Commit graph

1091 commits

Author SHA1 Message Date
Jens Axboe
8026e49bff mm/filemap: add read support for RWF_DONTCACHE
Add RWF_DONTCACHE as a read operation flag, which means that any data read
wil be removed from the page cache upon completion.  Uses the page cache
to synchronize, and simply prunes folios that were instantiated when the
operation completes.  While it would be possible to use private pages for
this, using the page cache as synchronization is handy for a variety of
reasons:

1) No special truncate magic is needed
2) Async buffered reads need some place to serialize, using the page
   cache is a lot easier than writing extra code for this
3) The pruning cost is pretty reasonable

and the code to support this is much simpler as a result.

You can think of uncached buffered IO as being the much more attractive
cousin of O_DIRECT - it has none of the restrictions of O_DIRECT.  Yes, it
will copy the data, but unlike regular buffered IO, it doesn't run into
the unpredictability of the page cache in terms of reclaim.  As an
example, on a test box with 32 drives, reading them with buffered IO looks
as follows:

Reading bs 65536, uncached 0
  1s: 145945MB/sec
  2s: 158067MB/sec
  3s: 157007MB/sec
  4s: 148622MB/sec
  5s: 118824MB/sec
  6s: 70494MB/sec
  7s: 41754MB/sec
  8s: 90811MB/sec
  9s: 92204MB/sec
 10s: 95178MB/sec
 11s: 95488MB/sec
 12s: 95552MB/sec
 13s: 96275MB/sec

where it's quite easy to see where the page cache filled up, and
performance went from good to erratic, and finally settles at a much
lower rate. Looking at top while this is ongoing, we see:

 PID USER      PR  NI    VIRT    RES    SHR S  %CPU  %MEM     TIME+ COMMAND
7535 root      20   0  267004      0      0 S  3199   0.0   8:40.65 uncached
3326 root      20   0       0      0      0 R 100.0   0.0   0:16.40 kswapd4
3327 root      20   0       0      0      0 R 100.0   0.0   0:17.22 kswapd5
3328 root      20   0       0      0      0 R 100.0   0.0   0:13.29 kswapd6
3332 root      20   0       0      0      0 R 100.0   0.0   0:11.11 kswapd10
3339 root      20   0       0      0      0 R 100.0   0.0   0:16.25 kswapd17
3348 root      20   0       0      0      0 R 100.0   0.0   0:16.40 kswapd26
3343 root      20   0       0      0      0 R 100.0   0.0   0:16.30 kswapd21
3344 root      20   0       0      0      0 R 100.0   0.0   0:11.92 kswapd22
3349 root      20   0       0      0      0 R 100.0   0.0   0:16.28 kswapd27
3352 root      20   0       0      0      0 R  99.7   0.0   0:11.89 kswapd30
3353 root      20   0       0      0      0 R  96.7   0.0   0:16.04 kswapd31
3329 root      20   0       0      0      0 R  96.4   0.0   0:11.41 kswapd7
3345 root      20   0       0      0      0 R  96.4   0.0   0:13.40 kswapd23
3330 root      20   0       0      0      0 S  91.1   0.0   0:08.28 kswapd8
3350 root      20   0       0      0      0 S  86.8   0.0   0:11.13 kswapd28
3325 root      20   0       0      0      0 S  76.3   0.0   0:07.43 kswapd3
3341 root      20   0       0      0      0 S  74.7   0.0   0:08.85 kswapd19
3334 root      20   0       0      0      0 S  71.7   0.0   0:10.04 kswapd12
3351 root      20   0       0      0      0 R  60.5   0.0   0:09.59 kswapd29
3323 root      20   0       0      0      0 R  57.6   0.0   0:11.50 kswapd1
[...]

which is just showing a partial list of the 32 kswapd threads that are
running mostly full tilt, burning ~28 full CPU cores.

If the same test case is run with RWF_DONTCACHE set for the buffered read,
the output looks as follows:

Reading bs 65536, uncached 0
  1s: 153144MB/sec
  2s: 156760MB/sec
  3s: 158110MB/sec
  4s: 158009MB/sec
  5s: 158043MB/sec
  6s: 157638MB/sec
  7s: 157999MB/sec
  8s: 158024MB/sec
  9s: 157764MB/sec
 10s: 157477MB/sec
 11s: 157417MB/sec
 12s: 157455MB/sec
 13s: 157233MB/sec
 14s: 156692MB/sec

which is just chugging along at ~155GB/sec of read performance. Looking
at top, we see:

 PID USER      PR  NI    VIRT    RES    SHR S  %CPU  %MEM     TIME+ COMMAND
7961 root      20   0  267004      0      0 S  3180   0.0   5:37.95 uncached
8024 axboe     20   0   14292   4096      0 R   1.0   0.0   0:00.13 top

where just the test app is using CPU, no reclaim is taking place outside
of the main thread.  Not only is performance 65% better, it's also using
half the CPU to do it.

Link: https://lkml.kernel.org/r/20241220154831.1086649-9-axboe@kernel.dk
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Cc: Brian Foster <bfoster@redhat.com>
Cc: Chris Mason <clm@meta.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-01-25 20:22:43 -08:00
Jens Axboe
f598cdaafc mm/filemap: use page_cache_sync_ra() to kick off read-ahead
Rather than use the page_cache_sync_readahead() helper, define our own
ractl and use page_cache_sync_ra() directly.  In preparation for needing
to modify ractl inside filemap_get_pages().

No functional changes in this patch.

Link: https://lkml.kernel.org/r/20241220154831.1086649-3-axboe@kernel.dk
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Brian Foster <bfoster@redhat.com>
Cc: Chris Mason <clm@meta.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-01-25 20:22:42 -08:00
Jens Axboe
9ad6344568 mm/filemap: change filemap_create_folio() to take a struct kiocb
Patch series "Uncached buffered IO", v8.

5 years ago I posted patches adding support for RWF_UNCACHED, as a way to
do buffered IO that isn't page cache persistent.  The approach back then
was to have private pages for IO, and then get rid of them once IO was
done.  But that then runs into all the issues that O_DIRECT has, in terms
of synchronizing with the page cache.

So here's a new approach to the same concent, but using the page cache as
synchronization.  Due to excessive bike shedding on the naming, this is
now named RWF_DONTCACHE, and is less special in that it's just page cache
IO, except it prunes the ranges once IO is completed.

Why do this, you may ask?  The tldr is that device speeds are only getting
faster, while reclaim is not.  Doing normal buffered IO can be very
unpredictable, and suck up a lot of resources on the reclaim side.  This
leads people to use O_DIRECT as a work-around, which has its own set of
restrictions in terms of size, offset, and length of IO.  It's also
inherently synchronous, and now you need async IO as well.  While the
latter isn't necessarily a big problem as we have good options available
there, it also should not be a requirement when all you want to do is read
or write some data without caching.

Even on desktop type systems, a normal NVMe device can fill the entire
page cache in seconds.  On the big system I used for testing, there's a
lot more RAM, but also a lot more devices.  As can be seen in some of the
results in the following patches, you can still fill RAM in seconds even
when there's 1TB of it.  Hence this problem isn't solely a "big
hyperscaler system" issue, it's common across the board.

Common for both reads and writes with RWF_DONTCACHE is that they use the
page cache for IO.  Reads work just like a normal buffered read would,
with the only exception being that the touched ranges will get pruned
after data has been copied.  For writes, the ranges will get writeback
kicked off before the syscall returns, and then writeback completion will
prune the range.  Hence writes aren't synchronous, and it's easy to
pipeline writes using RWF_DONTCACHE.  Folios that aren't instantiated by
RWF_DONTCACHE IO are left untouched.  This means you that uncached IO will
take advantage of the page cache for uptodate data, but not leave anything
it instantiated/created in cache.

File systems need to support this.  This patchset adds support for the
generic read path, which covers file systems like ext4.  Patches exist to
add support for iomap/XFS and btrfs as well, which sit on top of this
series.  If RWF_DONTCACHE IO is attempted on a file system that doesn't
support it, -EOPNOTSUPP is returned.  Hence the user can rely on it either
working as designed, or flagging and error if that's not the case.  The
intent here is to give the application a sensible fallback path - eg, it
may fall back to O_DIRECT if appropriate, or just live with the fact that
uncached IO isn't available and do normal buffered IO.

Adding "support" to other file systems should be trivial, most of the time
just a one-liner adding FOP_DONTCACHE to the fop_flags in the
file_operations struct, if the file system is using either iomap or the
generic filemap helpers for reading and writing.

Performance results are in patch 8 for reads, and you can find the write
side results in the XFS patch adding support for DONTCACHE writes for XFS:

https://git.kernel.dk/cgit/linux/commit/?h=buffered-uncached-fs.10&id=257e92de795fdff7d7e256501e024fac6da6a7f4

with the tldr being that I see about a 65% improvement in performance for
both, with fully predictable IO times.  CPU reduction is substantial as
well, with no kswapd activity at all for reclaim when using uncached IO.

Using it from applications is trivial - just set RWF_DONTCACHE for the
read or write, using pwritev2(2) or preadv2(2).  For io_uring, same thing,
just set RWF_DONTCACHE in sqe->rw_flags for a buffered read/write
operation.  And that's it.

Patches 1..7 are just prep patches, and should have no functional changes
at all.  Patch 8 adds support for the filemap path for RWF_DONTCACHE
reads, and patches 9..12 are just prep patches for supporting the write
side of uncached writes.  In the below mentioned branch, there are then
patches to adopt uncached reads and writes for xfs, btrfs, and ext4.  The
latter currently relies on bit of a hack for passing whether this is an
uncached write or not through ->write_begin(), which can hopefully go away
once ext4 adopts iomap for buffered writes.  I say this is a hack as it's
not the prettiest way to do it, however it is fully solid and will work
just fine.

Passes full xfstests and fsx overnight runs, no issues observed.  That
includes the vm running the testing also using RWF_DONTCACHE on the host. 
I'll post fsstress and fsx patches for RWF_DONTCACHE separately.  As far
as I'm concerned, no further work needs doing here.

And git tree for the patches is here:

https://git.kernel.dk/cgit/linux/log/?h=buffered-uncached.10

with the file system patches on top adding support for xfs/btrfs/ext4
here:

https://git.kernel.dk/cgit/linux/log/?h=buffered-uncached-fs.10


This patch (of 12):

Rather than pass in both the file and position directly from the kiocb,
just take a struct kiocb instead.  With the kiocb being passed in, skip
passing in the address_space separately as well.  While doing so, move the
ki_flags checking into filemap_create_folio() as well.  In preparation for
actually needing the kiocb in the function.

No functional changes in this patch.

Link: https://lkml.kernel.org/r/20241220154831.1086649-1-axboe@kernel.dk
Link: https://lkml.kernel.org/r/20241220154831.1086649-2-axboe@kernel.dk
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Brian Foster <bfoster@redhat.com>
Cc: Chris Mason <clm@meta.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-01-25 20:22:42 -08:00
Linus Torvalds
8883957b3c \n
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Merge tag 'fsnotify_hsm_for_v6.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs

Pull fsnotify pre-content notification support from Jan Kara:
 "This introduces a new fsnotify event (FS_PRE_ACCESS) that gets
  generated before a file contents is accessed.

  The event is synchronous so if there is listener for this event, the
  kernel waits for reply. On success the execution continues as usual,
  on failure we propagate the error to userspace. This allows userspace
  to fill in file content on demand from slow storage. The context in
  which the events are generated has been picked so that we don't hold
  any locks and thus there's no risk of a deadlock for the userspace
  handler.

  The new pre-content event is available only for users with global
  CAP_SYS_ADMIN capability (similarly to other parts of fanotify
  functionality) and it is an administrator responsibility to make sure
  the userspace event handler doesn't do stupid stuff that can DoS the
  system.

  Based on your feedback from the last submission, fsnotify code has
  been improved and now file->f_mode encodes whether pre-content event
  needs to be generated for the file so the fast path when nobody wants
  pre-content event for the file just grows the additional file->f_mode
  check. As a bonus this also removes the checks whether the old
  FS_ACCESS event needs to be generated from the fast path. Also the
  place where the event is generated during page fault has been moved so
  now filemap_fault() generates the event if and only if there is no
  uptodate folio in the page cache.

  Also we have dropped FS_PRE_MODIFY event as current real-world users
  of the pre-content functionality don't really use it so let's start
  with the minimal useful feature set"

* tag 'fsnotify_hsm_for_v6.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs: (21 commits)
  fanotify: Fix crash in fanotify_init(2)
  fs: don't block write during exec on pre-content watched files
  fs: enable pre-content events on supported file systems
  ext4: add pre-content fsnotify hook for DAX faults
  btrfs: disable defrag on pre-content watched files
  xfs: add pre-content fsnotify hook for DAX faults
  fsnotify: generate pre-content permission event on page fault
  mm: don't allow huge faults for files with pre content watches
  fanotify: disable readahead if we have pre-content watches
  fanotify: allow to set errno in FAN_DENY permission response
  fanotify: report file range info with pre-content events
  fanotify: introduce FAN_PRE_ACCESS permission event
  fsnotify: generate pre-content permission event on truncate
  fsnotify: pass optional file access range in pre-content event
  fsnotify: introduce pre-content permission events
  fanotify: reserve event bit of deprecated FAN_DIR_MODIFY
  fanotify: rename a misnamed constant
  fanotify: don't skip extra event info if no info_mode is set
  fsnotify: check if file is actually being watched for pre-content events on open
  fsnotify: opt-in for permission events at file open time
  ...
2025-01-23 13:36:06 -08:00
Linus Torvalds
5f537664e7 cachestat: fix page cache statistics permission checking
When the 'cachestat()' system call was added in commit cf264e1329
("cachestat: implement cachestat syscall"), it was meant to be a much
more convenient (and performant) version of mincore() that didn't need
mapping things into the user virtual address space in order to work.

But it ended up missing the "check for writability or ownership" fix for
mincore(), done in commit 134fca9063 ("mm/mincore.c: make mincore()
more conservative").

This just adds equivalent logic to 'cachestat()', modified for the file
context (rather than vma).

Reported-by: Sudheendra Raghav Neela <sneela@tugraz.at>
Fixes: cf264e1329 ("cachestat: implement cachestat syscall")
Tested-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Nhat Pham <nphamcs@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2025-01-21 20:30:19 -08:00
Dr. David Alan Gilbert
1168b2bec7 filemap: remove unused folio_add_wait_queue
folio_add_wait_queue() has been unused since 2021's commit 850cba069c
("cachefiles: Delete the cachefiles driver pending rewrite")

Remove it.

Link: https://lkml.kernel.org/r/20241116151446.95555-1-linux@treblig.org
Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-01-13 22:40:38 -08:00
Matthew Wilcox (Oracle)
1c47c57818 mm: fix assertion in folio_end_read()
We only need to assert that the uptodate flag is clear if we're going to
set it.  This hasn't been a problem before now because we have only used
folio_end_read() when completing with an error, but it's convenient to use
it in squashfs if we discover the folio is already uptodate.

Link: https://lkml.kernel.org/r/20250110163300.3346321-1-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Phillip Lougher <phillip@squashfs.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-01-12 19:03:38 -08:00
Marco Nelissen
f505e6c91e filemap: avoid truncating 64-bit offset to 32 bits
On 32-bit kernels, folio_seek_hole_data() was inadvertently truncating a
64-bit value to 32 bits, leading to a possible infinite loop when writing
to an xfs filesystem.

Link: https://lkml.kernel.org/r/20250102190540.1356838-1-marco.nelissen@gmail.com
Fixes: 54fa39ac2e ("iomap: use mapping_seek_hole_data")
Signed-off-by: Marco Nelissen <marco.nelissen@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-01-12 19:03:35 -08:00
Kairui Song
62e72d2cf7 mm, madvise: fix potential workingset node list_lru leaks
Since commit 5abc1e37af ("mm: list_lru: allocate list_lru_one only when
needed"), all list_lru users need to allocate the items using the new
infrastructure that provides list_lru info for slab allocation, ensuring
that the corresponding memcg list_lru is allocated before use.

For workingset shadow nodes (which are xa_node), users are converted to
use the new infrastructure by commit 9bbdc0f324 ("xarray: use
kmem_cache_alloc_lru to allocate xa_node").  The xas->xa_lru will be set
correctly for filemap users.  However, there is a missing case: xa_node
allocations caused by madvise(..., MADV_COLLAPSE).

madvise(..., MADV_COLLAPSE) will also read in the absent parts of file
map, and there will be xa_nodes allocated for the caller's memcg (assuming
it's not rootcg).  However, these allocations won't trigger memcg list_lru
allocation because the proper xas info was not set.

If nothing else has allocated other xa_nodes for that memcg to trigger
list_lru creation, and memory pressure starts to evict file pages,
workingset_update_node will try to add these xa_nodes to their
corresponding memcg list_lru, and it does not exist (NULL).  So they will
be added to rootcg's list_lru instead.

This shouldn't be a significant issue in practice, but it is indeed
unexpected behavior, and these xa_nodes will not be reclaimed effectively.
And may lead to incorrect counting of the list_lru->nr_items counter.

This problem wasn't exposed until recent commit 28e98022b3
("mm/list_lru: simplify reparenting and initial allocation") added a
sanity check: only dying memcg could have a NULL list_lru when
list_lru_{add,del} is called.  This problem triggered this WARNING.

So make madvise(..., MADV_COLLAPSE) also call xas_set_lru() to pass the
list_lru which we may want to insert xa_node into later.  And move
mapping_set_update to mm/internal.h, and turn into a macro to avoid
including extra headers in mm/internal.h.

Link: https://lkml.kernel.org/r/20241222122936.67501-1-ryncsn@gmail.com
Fixes: 9bbdc0f324 ("xarray: use kmem_cache_alloc_lru to allocate xa_node")
Reported-by: syzbot+38a0cbd267eff2d286ff@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/lkml/675d01e9.050a0220.37aaf.00be.GAE@google.com/
Signed-off-by: Kairui Song <kasong@tencent.com>
Cc: Chengming Zhou <chengming.zhou@linux.dev>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Sasha Levin <sashal@kernel.org>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-12-30 17:59:11 -08:00
Josef Bacik
8392bc2ff8 fsnotify: generate pre-content permission event on page fault
FS_PRE_ACCESS will be generated on page fault depending on the faulting
method. This pre-content event is meant to be used by hierarchical storage
managers that want to fill in the file content on first read access.

Export a simple helper that file systems that have their own ->fault()
will use, and have a more complicated helper to be do fancy things in
filemap_fault.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/aa56c50ce81b1fd18d7f5d71dd2dfced5eba9687.1731684329.git.josef@toxicpanda.com
2024-12-11 17:28:41 +01:00
Josef Bacik
fac84846a2 fanotify: disable readahead if we have pre-content watches
With page faults we can trigger readahead on the file, and then
subsequent faults can find these pages and insert them into the file
without emitting an fanotify event.  To avoid this case, disable
readahead if we have pre-content watches on the file.  This way we are
guaranteed to get an event for every range we attempt to access on a
pre-content watched file.

Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/70a54e859f555e54bc7a47b32fe5aca92b085615.1731684329.git.josef@toxicpanda.com
2024-12-10 12:03:17 +01:00
David Hildenbrand
3203b3ab0f mm/filemap: don't call folio_test_locked() without a reference in next_uptodate_folio()
The folio can get freed + buddy-merged + reallocated in the meantime,
resulting in us calling folio_test_locked() possibly on a tail page.

This makes const_folio_flags VM_BUG_ON_PGFLAGS() when stumbling over the
tail page.

Could this result in other issues?  Doesn't look like it.  False positives
and false negatives don't really matter, because this folio would get
skipped either way when detecting that they have been reallocated in the
meantime.

Fix it by performing the folio_test_locked() checked after grabbing a
reference.  If this ever becomes a real problem, we could add a special
helper that racily checks if the bit is set even on tail pages ...  but
let's hope that's not required so we can just handle it cleaner: work on
the folio after we hold a reference.

Do we really need the folio_test_locked() check if we are going to trylock
briefly after?  Well, we can at least avoid a xas_reload().

It's a bit unclear which exact change introduced that issue.  Likely, ever
since we made PG_locked obey to the PF_NO_TAIL policy it could have been
triggered in some way.

Link: https://lkml.kernel.org/r/20241129125303.4033164-1-david@redhat.com
Fixes: 48c935ad88 ("page-flags: define PG_locked behavior on compound pages")
Signed-off-by: David Hildenbrand <david@redhat.com>
Reported-by: syzbot+9f9a7f73fb079b2387a6@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/lkml/674184c9.050a0220.1cc393.0001.GAE@google.com/
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: Hillf Danton <hdanton@sina.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-12-05 19:54:47 -08:00
Linus Torvalds
5c00ff742b - The series "zram: optimal post-processing target selection" from
Sergey Senozhatsky improves zram's post-processing selection algorithm.
   This leads to improved memory savings.
 
 - Wei Yang has gone to town on the mapletree code, contributing several
   series which clean up the implementation:
 
 	- "refine mas_mab_cp()"
 	- "Reduce the space to be cleared for maple_big_node"
 	- "maple_tree: simplify mas_push_node()"
 	- "Following cleanup after introduce mas_wr_store_type()"
 	- "refine storing null"
 
 - The series "selftests/mm: hugetlb_fault_after_madv improvements" from
   David Hildenbrand fixes this selftest for s390.
 
 - The series "introduce pte_offset_map_{ro|rw}_nolock()" from Qi Zheng
   implements some rationaizations and cleanups in the page mapping code.
 
 - The series "mm: optimize shadow entries removal" from Shakeel Butt
   optimizes the file truncation code by speeding up the handling of shadow
   entries.
 
 - The series "Remove PageKsm()" from Matthew Wilcox completes the
   migration of this flag over to being a folio-based flag.
 
 - The series "Unify hugetlb into arch_get_unmapped_area functions" from
   Oscar Salvador implements a bunch of consolidations and cleanups in the
   hugetlb code.
 
 - The series "Do not shatter hugezeropage on wp-fault" from Dev Jain
   takes away the wp-fault time practice of turning a huge zero page into
   small pages.  Instead we replace the whole thing with a THP.  More
   consistent cleaner and potentiall saves a large number of pagefaults.
 
 - The series "percpu: Add a test case and fix for clang" from Andy
   Shevchenko enhances and fixes the kernel's built in percpu test code.
 
 - The series "mm/mremap: Remove extra vma tree walk" from Liam Howlett
   optimizes mremap() by avoiding doing things which we didn't need to do.
 
 - The series "Improve the tmpfs large folio read performance" from
   Baolin Wang teaches tmpfs to copy data into userspace at the folio size
   rather than as individual pages.  A 20% speedup was observed.
 
 - The series "mm/damon/vaddr: Fix issue in
   damon_va_evenly_split_region()" fro Zheng Yejian fixes DAMON splitting.
 
 - The series "memcg-v1: fully deprecate charge moving" from Shakeel Butt
   removes the long-deprecated memcgv2 charge moving feature.
 
 - The series "fix error handling in mmap_region() and refactor" from
   Lorenzo Stoakes cleanup up some of the mmap() error handling and
   addresses some potential performance issues.
 
 - The series "x86/module: use large ROX pages for text allocations" from
   Mike Rapoport teaches x86 to use large pages for read-only-execute
   module text.
 
 - The series "page allocation tag compression" from Suren Baghdasaryan
   is followon maintenance work for the new page allocation profiling
   feature.
 
 - The series "page->index removals in mm" from Matthew Wilcox remove
   most references to page->index in mm/.  A slow march towards shrinking
   struct page.
 
 - The series "damon/{self,kunit}tests: minor fixups for DAMON debugfs
   interface tests" from Andrew Paniakin performs maintenance work for
   DAMON's self testing code.
 
 - The series "mm: zswap swap-out of large folios" from Kanchana Sridhar
   improves zswap's batching of compression and decompression.  It is a
   step along the way towards using Intel IAA hardware acceleration for
   this zswap operation.
 
 - The series "kasan: migrate the last module test to kunit" from
   Sabyrzhan Tasbolatov completes the migration of the KASAN built-in tests
   over to the KUnit framework.
 
 - The series "implement lightweight guard pages" from Lorenzo Stoakes
   permits userapace to place fault-generating guard pages within a single
   VMA, rather than requiring that multiple VMAs be created for this.
   Improved efficiencies for userspace memory allocators are expected.
 
 - The series "memcg: tracepoint for flushing stats" from JP Kobryn uses
   tracepoints to provide increased visibility into memcg stats flushing
   activity.
 
 - The series "zram: IDLE flag handling fixes" from Sergey Senozhatsky
   fixes a zram buglet which potentially affected performance.
 
 - The series "mm: add more kernel parameters to control mTHP" from
   Maíra Canal enhances our ability to control/configuremultisize THP from
   the kernel boot command line.
 
 - The series "kasan: few improvements on kunit tests" from Sabyrzhan
   Tasbolatov has a couple of fixups for the KASAN KUnit tests.
 
 - The series "mm/list_lru: Split list_lru lock into per-cgroup scope"
   from Kairui Song optimizes list_lru memory utilization when lockdep is
   enabled.
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Merge tag 'mm-stable-2024-11-18-19-27' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:

 - The series "zram: optimal post-processing target selection" from
   Sergey Senozhatsky improves zram's post-processing selection
   algorithm. This leads to improved memory savings.

 - Wei Yang has gone to town on the mapletree code, contributing several
   series which clean up the implementation:
	- "refine mas_mab_cp()"
	- "Reduce the space to be cleared for maple_big_node"
	- "maple_tree: simplify mas_push_node()"
	- "Following cleanup after introduce mas_wr_store_type()"
	- "refine storing null"

 - The series "selftests/mm: hugetlb_fault_after_madv improvements" from
   David Hildenbrand fixes this selftest for s390.

 - The series "introduce pte_offset_map_{ro|rw}_nolock()" from Qi Zheng
   implements some rationaizations and cleanups in the page mapping
   code.

 - The series "mm: optimize shadow entries removal" from Shakeel Butt
   optimizes the file truncation code by speeding up the handling of
   shadow entries.

 - The series "Remove PageKsm()" from Matthew Wilcox completes the
   migration of this flag over to being a folio-based flag.

 - The series "Unify hugetlb into arch_get_unmapped_area functions" from
   Oscar Salvador implements a bunch of consolidations and cleanups in
   the hugetlb code.

 - The series "Do not shatter hugezeropage on wp-fault" from Dev Jain
   takes away the wp-fault time practice of turning a huge zero page
   into small pages. Instead we replace the whole thing with a THP. More
   consistent cleaner and potentiall saves a large number of pagefaults.

 - The series "percpu: Add a test case and fix for clang" from Andy
   Shevchenko enhances and fixes the kernel's built in percpu test code.

 - The series "mm/mremap: Remove extra vma tree walk" from Liam Howlett
   optimizes mremap() by avoiding doing things which we didn't need to
   do.

 - The series "Improve the tmpfs large folio read performance" from
   Baolin Wang teaches tmpfs to copy data into userspace at the folio
   size rather than as individual pages. A 20% speedup was observed.

 - The series "mm/damon/vaddr: Fix issue in
   damon_va_evenly_split_region()" fro Zheng Yejian fixes DAMON
   splitting.

 - The series "memcg-v1: fully deprecate charge moving" from Shakeel
   Butt removes the long-deprecated memcgv2 charge moving feature.

 - The series "fix error handling in mmap_region() and refactor" from
   Lorenzo Stoakes cleanup up some of the mmap() error handling and
   addresses some potential performance issues.

 - The series "x86/module: use large ROX pages for text allocations"
   from Mike Rapoport teaches x86 to use large pages for
   read-only-execute module text.

 - The series "page allocation tag compression" from Suren Baghdasaryan
   is followon maintenance work for the new page allocation profiling
   feature.

 - The series "page->index removals in mm" from Matthew Wilcox remove
   most references to page->index in mm/. A slow march towards shrinking
   struct page.

 - The series "damon/{self,kunit}tests: minor fixups for DAMON debugfs
   interface tests" from Andrew Paniakin performs maintenance work for
   DAMON's self testing code.

 - The series "mm: zswap swap-out of large folios" from Kanchana Sridhar
   improves zswap's batching of compression and decompression. It is a
   step along the way towards using Intel IAA hardware acceleration for
   this zswap operation.

 - The series "kasan: migrate the last module test to kunit" from
   Sabyrzhan Tasbolatov completes the migration of the KASAN built-in
   tests over to the KUnit framework.

 - The series "implement lightweight guard pages" from Lorenzo Stoakes
   permits userapace to place fault-generating guard pages within a
   single VMA, rather than requiring that multiple VMAs be created for
   this. Improved efficiencies for userspace memory allocators are
   expected.

 - The series "memcg: tracepoint for flushing stats" from JP Kobryn uses
   tracepoints to provide increased visibility into memcg stats flushing
   activity.

 - The series "zram: IDLE flag handling fixes" from Sergey Senozhatsky
   fixes a zram buglet which potentially affected performance.

 - The series "mm: add more kernel parameters to control mTHP" from
   Maíra Canal enhances our ability to control/configuremultisize THP
   from the kernel boot command line.

 - The series "kasan: few improvements on kunit tests" from Sabyrzhan
   Tasbolatov has a couple of fixups for the KASAN KUnit tests.

 - The series "mm/list_lru: Split list_lru lock into per-cgroup scope"
   from Kairui Song optimizes list_lru memory utilization when lockdep
   is enabled.

* tag 'mm-stable-2024-11-18-19-27' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (215 commits)
  cma: enforce non-zero pageblock_order during cma_init_reserved_mem()
  mm/kfence: add a new kunit test test_use_after_free_read_nofault()
  zram: fix NULL pointer in comp_algorithm_show()
  memcg/hugetlb: add hugeTLB counters to memcg
  vmstat: call fold_vm_zone_numa_events() before show per zone NUMA event
  mm: mmap_lock: check trace_mmap_lock_$type_enabled() instead of regcount
  zram: ZRAM_DEF_COMP should depend on ZRAM
  MAINTAINERS/MEMORY MANAGEMENT: add document files for mm
  Docs/mm/damon: recommend academic papers to read and/or cite
  mm: define general function pXd_init()
  kmemleak: iommu/iova: fix transient kmemleak false positive
  mm/list_lru: simplify the list_lru walk callback function
  mm/list_lru: split the lock to per-cgroup scope
  mm/list_lru: simplify reparenting and initial allocation
  mm/list_lru: code clean up for reparenting
  mm/list_lru: don't export list_lru_add
  mm/list_lru: don't pass unnecessary key parameters
  kasan: add kunit tests for kmalloc_track_caller, kmalloc_node_track_caller
  kasan: change kasan_atomics kunit test as KUNIT_CASE_SLOW
  kasan: use EXPORT_SYMBOL_IF_KUNIT to export symbols
  ...
2024-11-23 09:58:07 -08:00
Linus Torvalds
0f25f0e4ef the bulk of struct fd memory safety stuff
Making sure that struct fd instances are destroyed in the same
 scope where they'd been created, getting rid of reassignments
 and passing them by reference, converting to CLASS(fd{,_pos,_raw}).
 
 We are getting very close to having the memory safety of that stuff
 trivial to verify.
 
 Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Merge tag 'pull-fd' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull 'struct fd' class updates from Al Viro:
 "The bulk of struct fd memory safety stuff

  Making sure that struct fd instances are destroyed in the same scope
  where they'd been created, getting rid of reassignments and passing
  them by reference, converting to CLASS(fd{,_pos,_raw}).

  We are getting very close to having the memory safety of that stuff
  trivial to verify"

* tag 'pull-fd' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (28 commits)
  deal with the last remaing boolean uses of fd_file()
  css_set_fork(): switch to CLASS(fd_raw, ...)
  memcg_write_event_control(): switch to CLASS(fd)
  assorted variants of irqfd setup: convert to CLASS(fd)
  do_pollfd(): convert to CLASS(fd)
  convert do_select()
  convert vfs_dedupe_file_range().
  convert cifs_ioctl_copychunk()
  convert media_request_get_by_fd()
  convert spu_run(2)
  switch spufs_calls_{get,put}() to CLASS() use
  convert cachestat(2)
  convert do_preadv()/do_pwritev()
  fdget(), more trivial conversions
  fdget(), trivial conversions
  privcmd_ioeventfd_assign(): don't open-code eventfd_ctx_fdget()
  o2hb_region_dev_store(): avoid goto around fdget()/fdput()
  introduce "fd_pos" class, convert fdget_pos() users to it.
  fdget_raw() users: switch to CLASS(fd_raw)
  convert vmsplice() to CLASS(fd)
  ...
2024-11-18 12:24:06 -08:00
Linus Torvalds
70e7730c2a vfs-6.13.misc
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Merge tag 'vfs-6.13.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

Pull misc vfs updates from Christian Brauner:
 "Features:

   - Fixup and improve NLM and kNFSD file lock callbacks

     Last year both GFS2 and OCFS2 had some work done to make their
     locking more robust when exported over NFS. Unfortunately, part of
     that work caused both NLM (for NFS v3 exports) and kNFSD (for
     NFSv4.1+ exports) to no longer send lock notifications to clients

     This in itself is not a huge problem because most NFS clients will
     still poll the server in order to acquire a conflicted lock

     It's important for NLM and kNFSD that they do not block their
     kernel threads inside filesystem's file_lock implementations
     because that can produce deadlocks. We used to make sure of this by
     only trusting that posix_lock_file() can correctly handle blocking
     lock calls asynchronously, so the lock managers would only setup
     their file_lock requests for async callbacks if the filesystem did
     not define its own lock() file operation

     However, when GFS2 and OCFS2 grew the capability to correctly
     handle blocking lock requests asynchronously, they started
     signalling this behavior with EXPORT_OP_ASYNC_LOCK, and the check
     for also trusting posix_lock_file() was inadvertently dropped, so
     now most filesystems no longer produce lock notifications when
     exported over NFS

     Fix this by using an fop_flag which greatly simplifies the problem
     and grooms the way for future uses by both filesystems and lock
     managers alike

   - Add a sysctl to delete the dentry when a file is removed instead of
     making it a negative dentry

     Commit 681ce86235 ("vfs: Delete the associated dentry when
     deleting a file") introduced an unconditional deletion of the
     associated dentry when a file is removed. However, this led to
     performance regressions in specific benchmarks, such as
     ilebench.sum_operations/s, prompting a revert in commit
     4a4be1ad3a ("Revert "vfs: Delete the associated dentry when
     deleting a file""). This reintroduces the concept conditionally
     through a sysctl

   - Expand the statmount() system call:

       * Report the filesystem subtype in a new fs_subtype field to
         e.g., report fuse filesystem subtypes

       * Report the superblock source in a new sb_source field

       * Add a new way to return filesystem specific mount options in an
         option array that returns filesystem specific mount options
         separated by zero bytes and unescaped. This allows caller's to
         retrieve filesystem specific mount options and immediately pass
         them to e.g., fsconfig() without having to unescape or split
         them

       * Report security (LSM) specific mount options in a separate
         security option array. We don't lump them together with
         filesystem specific mount options as security mount options are
         generic and most users aren't interested in them

         The format is the same as for the filesystem specific mount
         option array

   - Support relative paths in fsconfig()'s FSCONFIG_SET_STRING command

   - Optimize acl_permission_check() to avoid costly {g,u}id ownership
     checks if possible

   - Use smp_mb__after_spinlock() to avoid full smp_mb() in evict()

   - Add synchronous wakeup support for ep_poll_callback.

     Currently, epoll only uses wake_up() to wake up task. But sometimes
     there are epoll users which want to use the synchronous wakeup flag
     to give a hint to the scheduler, e.g., the Android binder driver.
     So add a wake_up_sync() define, and use wake_up_sync() when sync is
     true in ep_poll_callback()

  Fixes:

   - Fix kernel documentation for inode_insert5() and iget5_locked()

   - Annotate racy epoll check on file->f_ep

   - Make F_DUPFD_QUERY associative

   - Avoid filename buffer overrun in initramfs

   - Don't let statmount() return empty strings

   - Add a cond_resched() to dump_user_range() to avoid hogging the CPU

   - Don't query the device logical blocksize multiple times for hfsplus

   - Make filemap_read() check that the offset is positive or zero

  Cleanups:

   - Various typo fixes

   - Cleanup wbc_attach_fdatawrite_inode()

   - Add __releases annotation to wbc_attach_and_unlock_inode()

   - Add hugetlbfs tracepoints

   - Fix various vfs kernel doc parameters

   - Remove obsolete TODO comment from io_cancel()

   - Convert wbc_account_cgroup_owner() to take a folio

   - Fix comments for BANDWITH_INTERVAL and wb_domain_writeout_add()

   - Reorder struct posix_acl to save 8 bytes

   - Annotate struct posix_acl with __counted_by()

   - Replace one-element array with flexible array member in freevxfs

   - Use idiomatic atomic64_inc_return() in alloc_mnt_ns()"

* tag 'vfs-6.13.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (35 commits)
  statmount: retrieve security mount options
  vfs: make evict() use smp_mb__after_spinlock instead of smp_mb
  statmount: add flag to retrieve unescaped options
  fs: add the ability for statmount() to report the sb_source
  writeback: wbc_attach_fdatawrite_inode out of line
  writeback: add a __releases annoation to wbc_attach_and_unlock_inode
  fs: add the ability for statmount() to report the fs_subtype
  fs: don't let statmount return empty strings
  fs:aio: Remove TODO comment suggesting hash or array usage in io_cancel()
  hfsplus: don't query the device logical block size multiple times
  freevxfs: Replace one-element array with flexible array member
  fs: optimize acl_permission_check()
  initramfs: avoid filename buffer overrun
  fs/writeback: convert wbc_account_cgroup_owner to take a folio
  acl: Annotate struct posix_acl with __counted_by()
  acl: Realign struct posix_acl to save 8 bytes
  epoll: Add synchronous wakeup support for ep_poll_callback
  coredump: add cond_resched() to dump_user_range
  mm/page-writeback.c: Fix comment of wb_domain_writeout_add()
  mm/page-writeback.c: Update comment for BANDWIDTH_INTERVAL
  ...
2024-11-18 09:35:30 -08:00
Trond Myklebust
ace149e083 filemap: Fix bounds checking in filemap_read()
If the caller supplies an iocb->ki_pos value that is close to the
filesystem upper limit, and an iterator with a count that causes us to
overflow that limit, then filemap_read() enters an infinite loop.

This behaviour was discovered when testing xfstests generic/525 with the
"localio" optimisation for loopback NFS mounts.

Reported-by: Mike Snitzer <snitzer@kernel.org>
Fixes: c2a9737f45 ("vfs,mm: fix a dead loop in truncate_inode_pages_range()")
Tested-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2024-11-10 14:07:08 -08:00
Shakeel Butt
a29c0e4b2e memcg-v1: remove memcg move locking code
The memcg v1's charge move feature has been deprecated.  All the places
using the memcg move lock, have stopped using it as they don't need the
protection any more.  Let's proceed to remove all the locking code related
to charge moving.

Link: https://lkml.kernel.org/r/20241025012304.2473312-7-shakeel.butt@linux.dev
Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Yosry Ahmed <yosryahmed@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-11-06 20:11:19 -08:00
Qi Zheng
bd6ad65ddc mm: filemap: filemap_fault_recheck_pte_none() use pte_offset_map_ro_nolock()
In filemap_fault_recheck_pte_none(), we just do pte_none() check, so
convert it to using pte_offset_map_ro_nolock().

Link: https://lkml.kernel.org/r/9f7cbbaa772385ced1b8931b67a8b9d246c9b82d.1727332572.git.zhengqi.arch@bytedance.com
Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Muchun Song <muchun.song@linux.dev>
Cc: Hugh Dickins <hughd@google.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: Peter Xu <peterx@redhat.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-11-05 16:56:26 -08:00
Al Viro
65c8941e7d convert cachestat(2)
fdput() can be transposed with copy_to_user()

Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2024-11-03 01:28:07 -05:00
Trond Myklebust
9d926f10b7
filemap: filemap_read() should check that the offset is positive or zero
We do check that the read offset is less than the filesystem limit,
however for good measure we should also check that it is positive or
zero, and return EINVAL if that is not the case.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Link: https://lore.kernel.org/r/482ee0b8a30b62324adb9f7c551a99926f037393.1726257832.git.trond.myklebust@hammerspace.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-10-02 07:52:12 +02:00
Steve Sistare
c225c4f605 mm/filemap: fix filemap_get_folios_contig THP panic
Patch series "memfd-pin huge page fixes".

Fix multiple bugs that occur when using memfd_pin_folios with hugetlb
pages and THP.  The hugetlb bugs only bite when the page is not yet
faulted in when memfd_pin_folios is called.  The THP bug bites when the
starting offset passed to memfd_pin_folios is not huge page aligned.  See
the commit messages for details.


This patch (of 5):

memfd_pin_folios on memory backed by THP panics if the requested start
offset is not huge page aligned:

BUG: kernel NULL pointer dereference, address: 0000000000000036
RIP: 0010:filemap_get_folios_contig+0xdf/0x290
RSP: 0018:ffffc9002092fbe8 EFLAGS: 00010202
RAX: 0000000000000002 RBX: 0000000000000002 RCX: 0000000000000002

The fault occurs here, because xas_load returns a folio with value 2:

    filemap_get_folios_contig()
        for (folio = xas_load(&xas); folio && xas.xa_index <= end;
                        folio = xas_next(&xas)) {
                ...
                if (!folio_try_get(folio))   <-- BOOM

"2" is an xarray sibling entry.  We get it because memfd_pin_folios does
not round the indices passed to filemap_get_folios_contig to huge page
boundaries for THP, so we load from the middle of a huge page range see a
sibling.  (It does round for hugetlbfs, at the is_file_hugepages test).

To fix, if the folio is a sibling, then return the next index as the
starting point for the next call to filemap_get_folios_contig.

Link: https://lkml.kernel.org/r/1725373521-451395-1-git-send-email-steven.sistare@oracle.com
Link: https://lkml.kernel.org/r/1725373521-451395-2-git-send-email-steven.sistare@oracle.com
Fixes: 89c1905d9c ("mm/gup: introduce memfd_pin_folios() for pinning memfd folios")
Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Peter Xu <peterx@redhat.com>
Cc: Vivek Kasireddy <vivek.kasireddy@intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-26 14:01:43 -07:00
Linus Torvalds
f8ffbc365f struct fd layout change (and conversion to accessor helpers)
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Merge tag 'pull-stable-struct_fd' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull 'struct fd' updates from Al Viro:
 "Just the 'struct fd' layout change, with conversion to accessor
  helpers"

* tag 'pull-stable-struct_fd' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  add struct fd constructors, get rid of __to_fd()
  struct fd: representation change
  introduce fd_file(), convert all accessors to it.
2024-09-23 09:35:36 -07:00
Linus Torvalds
617a814f14 ALong with the usual shower of singleton patches, notable patch series in
this pull request are:
 
 "Align kvrealloc() with krealloc()" from Danilo Krummrich.  Adds
 consistency to the APIs and behaviour of these two core allocation
 functions.  This also simplifies/enables Rustification.
 
 "Some cleanups for shmem" from Baolin Wang.  No functional changes - mode
 code reuse, better function naming, logic simplifications.
 
 "mm: some small page fault cleanups" from Josef Bacik.  No functional
 changes - code cleanups only.
 
 "Various memory tiering fixes" from Zi Yan.  A small fix and a little
 cleanup.
 
 "mm/swap: remove boilerplate" from Yu Zhao.  Code cleanups and
 simplifications and .text shrinkage.
 
 "Kernel stack usage histogram" from Pasha Tatashin and Shakeel Butt.  This
 is a feature, it adds new feilds to /proc/vmstat such as
 
     $ grep kstack /proc/vmstat
     kstack_1k 3
     kstack_2k 188
     kstack_4k 11391
     kstack_8k 243
     kstack_16k 0
 
 which tells us that 11391 processes used 4k of stack while none at all
 used 16k.  Useful for some system tuning things, but partivularly useful
 for "the dynamic kernel stack project".
 
 "kmemleak: support for percpu memory leak detect" from Pavel Tikhomirov.
 Teaches kmemleak to detect leaksage of percpu memory.
 
 "mm: memcg: page counters optimizations" from Roman Gushchin.  "3
 independent small optimizations of page counters".
 
 "mm: split PTE/PMD PT table Kconfig cleanups+clarifications" from David
 Hildenbrand.  Improves PTE/PMD splitlock detection, makes powerpc/8xx work
 correctly by design rather than by accident.
 
 "mm: remove arch_make_page_accessible()" from David Hildenbrand.  Some
 folio conversions which make arch_make_page_accessible() unneeded.
 
 "mm, memcg: cg2 memory{.swap,}.peak write handlers" fro David Finkel.
 Cleans up and fixes our handling of the resetting of the cgroup/process
 peak-memory-use detector.
 
 "Make core VMA operations internal and testable" from Lorenzo Stoakes.
 Rationalizaion and encapsulation of the VMA manipulation APIs.  With a
 view to better enable testing of the VMA functions, even from a
 userspace-only harness.
 
 "mm: zswap: fixes for global shrinker" from Takero Funaki.  Fix issues in
 the zswap global shrinker, resulting in improved performance.
 
 "mm: print the promo watermark in zoneinfo" from Kaiyang Zhao.  Fill in
 some missing info in /proc/zoneinfo.
 
 "mm: replace follow_page() by folio_walk" from David Hildenbrand.  Code
 cleanups and rationalizations (conversion to folio_walk()) resulting in
 the removal of follow_page().
 
 "improving dynamic zswap shrinker protection scheme" from Nhat Pham.  Some
 tuning to improve zswap's dynamic shrinker.  Significant reductions in
 swapin and improvements in performance are shown.
 
 "mm: Fix several issues with unaccepted memory" from Kirill Shutemov.
 Improvements to the new unaccepted memory feature,
 
 "mm/mprotect: Fix dax puds" from Peter Xu.  Implements mprotect on DAX
 PUDs.  This was missing, although nobody seems to have notied yet.
 
 "Introduce a store type enum for the Maple tree" from Sidhartha Kumar.
 Cleanups and modest performance improvements for the maple tree library
 code.
 
 "memcg: further decouple v1 code from v2" from Shakeel Butt.  Move more
 cgroup v1 remnants away from the v2 memcg code.
 
 "memcg: initiate deprecation of v1 features" from Shakeel Butt.  Adds
 various warnings telling users that memcg v1 features are deprecated.
 
 "mm: swap: mTHP swap allocator base on swap cluster order" from Chris Li.
 Greatly improves the success rate of the mTHP swap allocation.
 
 "mm: introduce numa_memblks" from Mike Rapoport.  Moves various disparate
 per-arch implementations of numa_memblk code into generic code.
 
 "mm: batch free swaps for zap_pte_range()" from Barry Song.  Greatly
 improves the performance of munmap() of swap-filled ptes.
 
 "support large folio swap-out and swap-in for shmem" from Baolin Wang.
 With this series we no longer split shmem large folios into simgle-page
 folios when swapping out shmem.
 
 "mm/hugetlb: alloc/free gigantic folios" from Yu Zhao.  Nice performance
 improvements and code reductions for gigantic folios.
 
 "support shmem mTHP collapse" from Baolin Wang.  Adds support for
 khugepaged's collapsing of shmem mTHP folios.
 
 "mm: Optimize mseal checks" from Pedro Falcato.  Fixes an mprotect()
 performance regression due to the addition of mseal().
 
 "Increase the number of bits available in page_type" from Matthew Wilcox.
 Increases the number of bits available in page_type!
 
 "Simplify the page flags a little" from Matthew Wilcox.  Many legacy page
 flags are now folio flags, so the page-based flags and their
 accessors/mutators can be removed.
 
 "mm: store zero pages to be swapped out in a bitmap" from Usama Arif.  An
 optimization which permits us to avoid writing/reading zero-filled zswap
 pages to backing store.
 
 "Avoid MAP_FIXED gap exposure" from Liam Howlett.  Fixes a race window
 which occurs when a MAP_FIXED operqtion is occurring during an unrelated
 vma tree walk.
 
 "mm: remove vma_merge()" from Lorenzo Stoakes.  Major rotorooting of the
 vma_merge() functionality, making ot cleaner, more testable and better
 tested.
 
 "misc fixups for DAMON {self,kunit} tests" from SeongJae Park.  Minor
 fixups of DAMON selftests and kunit tests.
 
 "mm: memory_hotplug: improve do_migrate_range()" from Kefeng Wang.  Code
 cleanups and folio conversions.
 
 "Shmem mTHP controls and stats improvements" from Ryan Roberts.  Cleanups
 for shmem controls and stats.
 
 "mm: count the number of anonymous THPs per size" from Barry Song.  Expose
 additional anon THP stats to userspace for improved tuning.
 
 "mm: finish isolate/putback_lru_page()" from Kefeng Wang: more folio
 conversions and removal of now-unused page-based APIs.
 
 "replace per-quota region priorities histogram buffer with per-context
 one" from SeongJae Park.  DAMON histogram rationalization.
 
 "Docs/damon: update GitHub repo URLs and maintainer-profile" from SeongJae
 Park.  DAMON documentation updates.
 
 "mm/vdpa: correct misuse of non-direct-reclaim __GFP_NOFAIL and improve
 related doc and warn" from Jason Wang: fixes usage of page allocator
 __GFP_NOFAIL and GFP_ATOMIC flags.
 
 "mm: split underused THPs" from Yu Zhao.  Improve THP=always policy - this
 was overprovisioning THPs in sparsely accessed memory areas.
 
 "zram: introduce custom comp backends API" frm Sergey Senozhatsky.  Add
 support for zram run-time compression algorithm tuning.
 
 "mm: Care about shadow stack guard gap when getting an unmapped area" from
 Mark Brown.  Fix up the various arch_get_unmapped_area() implementations
 to better respect guard areas.
 
 "Improve mem_cgroup_iter()" from Kinsey Ho.  Improve the reliability of
 mem_cgroup_iter() and various code cleanups.
 
 "mm: Support huge pfnmaps" from Peter Xu.  Extends the usage of huge
 pfnmap support.
 
 "resource: Fix region_intersects() vs add_memory_driver_managed()" from
 Huang Ying.  Fix a bug in region_intersects() for systems with CXL memory.
 
 "mm: hwpoison: two more poison recovery" from Kefeng Wang.  Teaches a
 couple more code paths to correctly recover from the encountering of
 poisoned memry.
 
 "mm: enable large folios swap-in support" from Barry Song.  Support the
 swapin of mTHP memory into appropriately-sized folios, rather than into
 single-page folios.
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Merge tag 'mm-stable-2024-09-20-02-31' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:
 "Along with the usual shower of singleton patches, notable patch series
  in this pull request are:

   - "Align kvrealloc() with krealloc()" from Danilo Krummrich. Adds
     consistency to the APIs and behaviour of these two core allocation
     functions. This also simplifies/enables Rustification.

   - "Some cleanups for shmem" from Baolin Wang. No functional changes -
     mode code reuse, better function naming, logic simplifications.

   - "mm: some small page fault cleanups" from Josef Bacik. No
     functional changes - code cleanups only.

   - "Various memory tiering fixes" from Zi Yan. A small fix and a
     little cleanup.

   - "mm/swap: remove boilerplate" from Yu Zhao. Code cleanups and
     simplifications and .text shrinkage.

   - "Kernel stack usage histogram" from Pasha Tatashin and Shakeel
     Butt. This is a feature, it adds new feilds to /proc/vmstat such as

       $ grep kstack /proc/vmstat
       kstack_1k 3
       kstack_2k 188
       kstack_4k 11391
       kstack_8k 243
       kstack_16k 0

     which tells us that 11391 processes used 4k of stack while none at
     all used 16k. Useful for some system tuning things, but
     partivularly useful for "the dynamic kernel stack project".

   - "kmemleak: support for percpu memory leak detect" from Pavel
     Tikhomirov. Teaches kmemleak to detect leaksage of percpu memory.

   - "mm: memcg: page counters optimizations" from Roman Gushchin. "3
     independent small optimizations of page counters".

   - "mm: split PTE/PMD PT table Kconfig cleanups+clarifications" from
     David Hildenbrand. Improves PTE/PMD splitlock detection, makes
     powerpc/8xx work correctly by design rather than by accident.

   - "mm: remove arch_make_page_accessible()" from David Hildenbrand.
     Some folio conversions which make arch_make_page_accessible()
     unneeded.

   - "mm, memcg: cg2 memory{.swap,}.peak write handlers" fro David
     Finkel. Cleans up and fixes our handling of the resetting of the
     cgroup/process peak-memory-use detector.

   - "Make core VMA operations internal and testable" from Lorenzo
     Stoakes. Rationalizaion and encapsulation of the VMA manipulation
     APIs. With a view to better enable testing of the VMA functions,
     even from a userspace-only harness.

   - "mm: zswap: fixes for global shrinker" from Takero Funaki. Fix
     issues in the zswap global shrinker, resulting in improved
     performance.

   - "mm: print the promo watermark in zoneinfo" from Kaiyang Zhao. Fill
     in some missing info in /proc/zoneinfo.

   - "mm: replace follow_page() by folio_walk" from David Hildenbrand.
     Code cleanups and rationalizations (conversion to folio_walk())
     resulting in the removal of follow_page().

   - "improving dynamic zswap shrinker protection scheme" from Nhat
     Pham. Some tuning to improve zswap's dynamic shrinker. Significant
     reductions in swapin and improvements in performance are shown.

   - "mm: Fix several issues with unaccepted memory" from Kirill
     Shutemov. Improvements to the new unaccepted memory feature,

   - "mm/mprotect: Fix dax puds" from Peter Xu. Implements mprotect on
     DAX PUDs. This was missing, although nobody seems to have notied
     yet.

   - "Introduce a store type enum for the Maple tree" from Sidhartha
     Kumar. Cleanups and modest performance improvements for the maple
     tree library code.

   - "memcg: further decouple v1 code from v2" from Shakeel Butt. Move
     more cgroup v1 remnants away from the v2 memcg code.

   - "memcg: initiate deprecation of v1 features" from Shakeel Butt.
     Adds various warnings telling users that memcg v1 features are
     deprecated.

   - "mm: swap: mTHP swap allocator base on swap cluster order" from
     Chris Li. Greatly improves the success rate of the mTHP swap
     allocation.

   - "mm: introduce numa_memblks" from Mike Rapoport. Moves various
     disparate per-arch implementations of numa_memblk code into generic
     code.

   - "mm: batch free swaps for zap_pte_range()" from Barry Song. Greatly
     improves the performance of munmap() of swap-filled ptes.

   - "support large folio swap-out and swap-in for shmem" from Baolin
     Wang. With this series we no longer split shmem large folios into
     simgle-page folios when swapping out shmem.

   - "mm/hugetlb: alloc/free gigantic folios" from Yu Zhao. Nice
     performance improvements and code reductions for gigantic folios.

   - "support shmem mTHP collapse" from Baolin Wang. Adds support for
     khugepaged's collapsing of shmem mTHP folios.

   - "mm: Optimize mseal checks" from Pedro Falcato. Fixes an mprotect()
     performance regression due to the addition of mseal().

   - "Increase the number of bits available in page_type" from Matthew
     Wilcox. Increases the number of bits available in page_type!

   - "Simplify the page flags a little" from Matthew Wilcox. Many legacy
     page flags are now folio flags, so the page-based flags and their
     accessors/mutators can be removed.

   - "mm: store zero pages to be swapped out in a bitmap" from Usama
     Arif. An optimization which permits us to avoid writing/reading
     zero-filled zswap pages to backing store.

   - "Avoid MAP_FIXED gap exposure" from Liam Howlett. Fixes a race
     window which occurs when a MAP_FIXED operqtion is occurring during
     an unrelated vma tree walk.

   - "mm: remove vma_merge()" from Lorenzo Stoakes. Major rotorooting of
     the vma_merge() functionality, making ot cleaner, more testable and
     better tested.

   - "misc fixups for DAMON {self,kunit} tests" from SeongJae Park.
     Minor fixups of DAMON selftests and kunit tests.

   - "mm: memory_hotplug: improve do_migrate_range()" from Kefeng Wang.
     Code cleanups and folio conversions.

   - "Shmem mTHP controls and stats improvements" from Ryan Roberts.
     Cleanups for shmem controls and stats.

   - "mm: count the number of anonymous THPs per size" from Barry Song.
     Expose additional anon THP stats to userspace for improved tuning.

   - "mm: finish isolate/putback_lru_page()" from Kefeng Wang: more
     folio conversions and removal of now-unused page-based APIs.

   - "replace per-quota region priorities histogram buffer with
     per-context one" from SeongJae Park. DAMON histogram
     rationalization.

   - "Docs/damon: update GitHub repo URLs and maintainer-profile" from
     SeongJae Park. DAMON documentation updates.

   - "mm/vdpa: correct misuse of non-direct-reclaim __GFP_NOFAIL and
     improve related doc and warn" from Jason Wang: fixes usage of page
     allocator __GFP_NOFAIL and GFP_ATOMIC flags.

   - "mm: split underused THPs" from Yu Zhao. Improve THP=always policy.
     This was overprovisioning THPs in sparsely accessed memory areas.

   - "zram: introduce custom comp backends API" frm Sergey Senozhatsky.
     Add support for zram run-time compression algorithm tuning.

   - "mm: Care about shadow stack guard gap when getting an unmapped
     area" from Mark Brown. Fix up the various arch_get_unmapped_area()
     implementations to better respect guard areas.

   - "Improve mem_cgroup_iter()" from Kinsey Ho. Improve the reliability
     of mem_cgroup_iter() and various code cleanups.

   - "mm: Support huge pfnmaps" from Peter Xu. Extends the usage of huge
     pfnmap support.

   - "resource: Fix region_intersects() vs add_memory_driver_managed()"
     from Huang Ying. Fix a bug in region_intersects() for systems with
     CXL memory.

   - "mm: hwpoison: two more poison recovery" from Kefeng Wang. Teaches
     a couple more code paths to correctly recover from the encountering
     of poisoned memry.

   - "mm: enable large folios swap-in support" from Barry Song. Support
     the swapin of mTHP memory into appropriately-sized folios, rather
     than into single-page folios"

* tag 'mm-stable-2024-09-20-02-31' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (416 commits)
  zram: free secondary algorithms names
  uprobes: turn xol_area->pages[2] into xol_area->page
  uprobes: introduce the global struct vm_special_mapping xol_mapping
  Revert "uprobes: use vm_special_mapping close() functionality"
  mm: support large folios swap-in for sync io devices
  mm: add nr argument in mem_cgroup_swapin_uncharge_swap() helper to support large folios
  mm: fix swap_read_folio_zeromap() for large folios with partial zeromap
  mm/debug_vm_pgtable: Use pxdp_get() for accessing page table entries
  set_memory: add __must_check to generic stubs
  mm/vma: return the exact errno in vms_gather_munmap_vmas()
  memcg: cleanup with !CONFIG_MEMCG_V1
  mm/show_mem.c: report alloc tags in human readable units
  mm: support poison recovery from copy_present_page()
  mm: support poison recovery from do_cow_fault()
  resource, kunit: add test case for region_intersects()
  resource: make alloc_free_mem_region() works for iomem_resource
  mm: z3fold: deprecate CONFIG_Z3FOLD
  vfio/pci: implement huge_fault support
  mm/arm64: support large pfn mappings
  mm/x86: support large pfn mappings
  ...
2024-09-21 07:29:05 -07:00
Linus Torvalds
171754c380 vfs-6.12.blocksize
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Merge tag 'vfs-6.12.blocksize' of gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs

Pull vfs blocksize updates from Christian Brauner:
 "This contains the vfs infrastructure as well as the xfs bits to enable
  support for block sizes (bs) larger than page sizes (ps) plus a few
  fixes to related infrastructure.

  There has been efforts over the last 16 years to enable enable Large
  Block Sizes (LBS), that is block sizes in filesystems where bs > page
  size. Through these efforts we have learned that one of the main
  blockers to supporting bs > ps in filesystems has been a way to
  allocate pages that are at least the filesystem block size on the page
  cache where bs > ps.

  Thanks to various previous efforts it is possible to support bs > ps
  in XFS with only a few changes in XFS itself. Most changes are to the
  page cache to support minimum order folio support for the target block
  size on the filesystem.

  A motivation for Large Block Sizes today is to support high-capacity
  (large amount of Terabytes) QLC SSDs where the internal Indirection
  Unit (IU) are typically greater than 4k to help reduce DRAM and so in
  turn cost and space. In practice this then allows different
  architectures to use a base page size of 4k while still enabling
  support for block sizes aligned to the larger IUs by relying on high
  order folios on the page cache when needed.

  It also allows to take advantage of the drive's support for atomics
  larger than 4k with buffered IO support in Linux. As described this
  year at LSFMM, supporting large atomics greater than 4k enables
  databases to remove the need to rely on their own journaling, so they
  can disable double buffered writes, which is a feature different cloud
  providers are already enabling through custom storage solutions"

* tag 'vfs-6.12.blocksize' of gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs: (22 commits)
  Documentation: iomap: fix a typo
  iomap: remove the iomap_file_buffered_write_punch_delalloc return value
  iomap: pass the iomap to the punch callback
  iomap: pass flags to iomap_file_buffered_write_punch_delalloc
  iomap: improve shared block detection in iomap_unshare_iter
  iomap: handle a post-direct I/O invalidate race in iomap_write_delalloc_release
  docs:filesystems: fix spelling and grammar mistakes in iomap design page
  filemap: fix htmldoc warning for mapping_align_index()
  iomap: make zero range flush conditional on unwritten mappings
  iomap: fix handling of dirty folios over unwritten extents
  iomap: add a private argument for iomap_file_buffered_write
  iomap: remove set_memor_ro() on zero page
  xfs: enable block size larger than page size support
  xfs: make the calculation generic in xfs_sb_validate_fsb_count()
  xfs: expose block size in stat
  xfs: use kvmalloc for xattr buffers
  iomap: fix iomap_dio_zero() for fs bs > system page size
  filemap: cap PTE range to be created to allowed zero fill in folio_map_range()
  mm: split a folio in minimum folio order chunks
  readahead: allocate folios with mapping_min_order in readahead
  ...
2024-09-20 17:53:17 -07:00
Linus Torvalds
adfc3ded5c for-6.12/io_uring-discard-20240913
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Merge tag 'for-6.12/io_uring-discard-20240913' of git://git.kernel.dk/linux

Pull io_uring async discard support from Jens Axboe:
 "Sitting on top of both the 6.12 block and io_uring core branches,
  here's support for async discard through io_uring.

  This allows applications to issue async discards, rather than rely on
  the blocking sync ioctl discards we already have. The sync support is
  difficult to use outside of idle/cleanup periods.

  On a real (but slow) device, testing shows the following results when
  compared to sync discard:

	qd64 sync discard: 21K IOPS, lat avg 3 msec (max 21 msec)
	qd64 async discard: 76K IOPS, lat avg 845 usec (max 2.2 msec)

	qd64 sync discard: 14K IOPS, lat avg 5 msec (max 25 msec)
	qd64 async discard: 56K IOPS, lat avg 1153 usec (max 3.6 msec)

  and synthetic null_blk testing with the same queue depth and block
  size settings as above shows:

	Type    Trim size       IOPS    Lat avg (usec)  Lat Max (usec)
	==============================================================
	sync    4k               144K       444            20314
	async   4k              1353K        47              595
	sync    1M                56K      1136            21031
	async   1M                94K       680              760"

* tag 'for-6.12/io_uring-discard-20240913' of git://git.kernel.dk/linux:
  block: implement async io_uring discard cmd
  block: introduce blk_validate_byte_range()
  filemap: introduce filemap_invalidate_pages
  io_uring/cmd: give inline space in request to cmds
  io_uring/cmd: expose iowq to cmds
2024-09-16 13:50:14 +02:00
Linus Torvalds
2775df6e5e vfs-6.12.folio
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Merge tag 'vfs-6.12.folio' of gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs

Pull vfs folio updates from Christian Brauner:
 "This contains work to port write_begin and write_end to rely on folios
  for various filesystems.

  This converts ocfs2, vboxfs, orangefs, jffs2, hostfs, fuse, f2fs,
  ecryptfs, ntfs3, nilfs2, reiserfs, minixfs, qnx6, sysv, ufs, and
  squashfs.

  After this series lands a bunch of the filesystems in this list do not
  mention struct page anymore"

* tag 'vfs-6.12.folio' of gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs: (61 commits)
  Squashfs: Ensure all readahead pages have been used
  Squashfs: Rewrite and update squashfs_readahead_fragment() to not use page->index
  Squashfs: Update squashfs_readpage_block() to not use page->index
  Squashfs: Update squashfs_readahead() to not use page->index
  Squashfs: Update page_actor to not use page->index
  jffs2: Use a folio in jffs2_garbage_collect_dnode()
  jffs2: Convert jffs2_do_readpage_nolock to take a folio
  buffer: Convert __block_write_begin() to take a folio
  ocfs2: Convert ocfs2_write_zero_page to use a folio
  fs: Convert aops->write_begin to take a folio
  fs: Convert aops->write_end to take a folio
  vboxsf: Use a folio in vboxsf_write_end()
  orangefs: Convert orangefs_write_begin() to use a folio
  orangefs: Convert orangefs_write_end() to use a folio
  jffs2: Convert jffs2_write_begin() to use a folio
  jffs2: Convert jffs2_write_end() to use a folio
  hostfs: Convert hostfs_write_end() to use a folio
  fuse: Convert fuse_write_begin() to use a folio
  fuse: Convert fuse_write_end() to use a folio
  f2fs: Convert f2fs_write_begin() to use a folio
  ...
2024-09-16 08:54:30 +02:00
Pavel Begunkov
a12c883a0a filemap: introduce filemap_invalidate_pages
kiocb_invalidate_pages() is useful for the write path, however not
everything is backed by kiocb and we want to reuse the function for bio
based discard implementation. Extract and and reuse a new helper called
filemap_invalidate_pages(), which takes a argument indicating whether it
should be non-blocking and might return -EAGAIN.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/f81374b52c92d0dce0f01a279d1eed42b54056aa.1726072086.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-09-11 10:44:10 -06:00
Shakeel Butt
354a595a4a mm: replace xa_get_order with xas_get_order where appropriate
The tracing of invalidation and truncation operations on large files
showed that xa_get_order() is among the top functions where kernel spends
a lot of CPUs.  xa_get_order() needs to traverse the tree to reach the
right node for a given index and then extract the order of the entry. 
However it seems like at many places it is being called within an already
happening tree traversal where there is no need to do another traversal. 
Just use xas_get_order() at those places.

Link: https://lkml.kernel.org/r/20240906230512.124643-1-shakeel.butt@linux.dev
Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Nhat Pham <nphamcs@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-09 16:39:17 -07:00
Takaya Saeki
fc1b43c422 filemap: fix the last_index of mm_filemap_get_pages
In commit b6273b55d8 ("filemap: add trace events for get_pages,
map_pages, and fault"), mm_filemap_get_pages was added to trace page cache
access.  However, it tracks an extra page beyond the end of the accessed
range.  This patch fixes it by replacing last_index with last_index - 1.

Link: https://lkml.kernel.org/r/20240903102100.70405-1-takayas@chromium.org
Fixes: b6273b55d8 ("filemap: add trace events for get_pages, map_pages, and fault")
Signed-off-by: Takaya Saeki <takayas@chromium.org>
Cc: Junichi Uekawa <uekawa@chromium.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-09 16:39:12 -07:00
Kefeng Wang
775d28fd45 mm: remove isolate_lru_page()
There are no more callers of isolate_lru_page(), remove it.

[wangkefeng.wang@huawei.com: convert page to folio in comment and document, per Matthew]
  Link: https://lkml.kernel.org/r/20240826144114.1928071-1-wangkefeng.wang@huawei.com
Link: https://lkml.kernel.org/r/20240826065814.1336616-6-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-09 16:38:59 -07:00
Yafang Shao
0a2d82946b mm: allow read-ahead with IOCB_NOWAIT set
Readahead support for IOCB_NOWAIT was introduced in commit 2e85abf053
("mm: allow read-ahead with IOCB_NOWAIT set").  However, this
implementation broke the semantics of IOCB_NOWAIT by potentially causing
it to wait on I/O during memory reclamation.  This behavior was later
modified in commit efa8480a83 ("fs: RWF_NOWAIT should imply IOCB_NOIO").

To resolve the blocking issue during memory reclamation, we can use
memalloc_noio_{save,restore} to ensure non-blocking behavior.  This change
restores the original functionality, allowing preadv2(IOCB_NOWAIT) to
trigger readahead if the file content is not present in the page cache.

While this process may trigger direct memory reclamation, the
__GFP_NORETRY flag is set in the readahead GFP flags, ensuring it won't
block.

A use case for this change is when we want to trigger readahead in the
preadv2(2) syscall if the file cache is absent, but without waiting for
certain filesystem locks, like xfs_ilock.  A simple example is as follows:

retry:
    if (preadv2(fd, iovec, cnt, offset, RWF_NOWAIT) < 0) {
        do_other_work();
        goto retry;
    }

Link: https://lore.gnuweeb.org/io-uring/20200624164127.GP21350@casper.infradead.org/
Link: https://lkml.kernel.org/r/20240820022639.89562-1-laoar.shao@gmail.com
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Christian Brauner <brauner@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-03 21:15:40 -07:00
Baolin Wang
fb72415938 mm: filemap: use xa_get_order() to get the swap entry order
In the following patches, shmem will support the swap out of large folios,
which means the shmem mappings may contain large order swap entries, so
using xa_get_order() to get the folio order of the shmem swap entry to
update the '*start' correctly.

[hughd@google.com: use xa_get_order() to get the swap entry order]
  Link: https://lkml.kernel.org/r/c336e6e4-da7f-b714-c0f1-12df715f2611@google.com
Link: https://lkml.kernel.org/r/6876d55145c1cc80e79df7884aa3a62e397b101d.1723434324.git.baolin.wang@linux.alibaba.com
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Chris Li <chrisl@kernel.org>
Cc: Daniel Gomez <da.gomez@samsung.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Lance Yang <ioworker0@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Pankaj Raghav <p.raghav@samsung.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-03 21:15:34 -07:00
Pankaj Raghav
743a2753a0 filemap: cap PTE range to be created to allowed zero fill in folio_map_range()
Usually the page cache does not extend beyond the size of the inode,
therefore, no PTEs are created for folios that extend beyond the size.

But with LBS support, we might extend page cache beyond the size of the
inode as we need to guarantee folios of minimum order. While doing a
read, do_fault_around() can create PTEs for pages that lie beyond the
EOF leading to incorrect error return when accessing a page beyond the
mapped file.

Cap the PTE range to be created for the page cache up to the end of
file(EOF) in filemap_map_pages() so that return error codes are consistent
with POSIX[1] for LBS configurations.

generic/749 has been created to trigger this edge case. This also fixes
generic/749 for tmpfs with huge=always on systems with 4k base page size.

[1](from mmap(2))  SIGBUS
    Attempted access to a page of the buffer that lies beyond the end
    of the mapped file.  For an explanation of the treatment  of  the
    bytes  in  the  page that corresponds to the end of a mapped file
    that is not a multiple of the page size, see NOTES.

Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Pankaj Raghav <p.raghav@samsung.com>
Link: https://lore.kernel.org/r/20240822135018.1931258-6-kernel@pankajraghav.com
Tested-by: David Howells <dhowells@redhat.com>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Daniel Gomez <da.gomez@samsung.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-09-02 16:19:43 +02:00
Takaya Saeki
b6273b55d8 filemap: add trace events for get_pages, map_pages, and fault
To allow precise tracking of page caches accessed, add new tracepoints
that trigger when a process actually accesses them.

The ureadahead program used by ChromeOS traces the disk access of programs
as they start up at boot up.  It uses mincore(2) or the
'mm_filemap_add_to_page_cache' trace event to accomplish this.  It stores
this information in a "pack" file and on subsequent boots, it will read
the pack file and call readahead(2) on the information so that disk
storage can be loaded into RAM before the applications actually need it.

A problem we see is that due to the kernel's readahead algorithm that can
aggressively pull in more data than needed (to try and accomplish the same
goal) and this data is also recorded.  The end result is that the pack
file contains a lot of pages on disk that are never actually used. 
Calling readahead(2) on these unused pages can slow down the system boot
up times.

To solve this, add 3 new trace events, get_pages, map_pages, and fault. 
These will be used to trace the pages are not only pulled in from disk,
but are actually used by the application.  Only those pages will be stored
in the pack file, and this helps out the performance of boot up.

With the combination of these 3 new trace events and
mm_filemap_add_to_page_cache, we observed a reduction in the pack file by
7.3% - 20% on ChromeOS varying by device.

Link: https://lkml.kernel.org/r/20240813100312.3930505-1-takayas@chromium.org
Signed-off-by: Takaya Saeki <takayas@chromium.org>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: Junichi Uekawa <uekawa@chromium.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01 20:26:10 -07:00
Matthew Wilcox (Oracle)
420e05d0de fs: remove calls to set and clear the folio error flag
Nobody checks the folio error flag any more, so we can stop setting and
clearing it.  Also remove the documentation suggesting to not bother
setting the error bit.

Link: https://lkml.kernel.org/r/20240807193528.1865100-1-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01 20:26:04 -07:00
David Hildenbrand
7290840de6 mm: remove follow_page()
All users are gone, let's remove it and any leftovers in comments.  We'll
leave any FOLL/follow_page_() naming cleanups as future work.

Link: https://lkml.kernel.org/r/20240802155524.517137-11-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Claudio Imbrenda <imbrenda@linux.ibm.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Janosch Frank <frankja@linux.ibm.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01 20:26:01 -07:00
David Howells
c26096ee02
mm: Fix filemap_invalidate_inode() to use invalidate_inode_pages2_range()
Fix filemap_invalidate_inode() to use invalidate_inode_pages2_range()
rather than truncate_inode_pages_range().  The latter clears the
invalidated bit of a partial pages rather than discarding it entirely.
This causes copy_file_range() to fail on cifs because the partial pages at
either end of the destination range aren't evicted and reread, but rather
just partly cleared.

This causes generic/075 and generic/112 xfstests to fail.

Fixes: 74e797d79c ("mm: Provide a means of invalidation without using launder_folio")
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20240828210249.1078637-5-dhowells@redhat.com
cc: Matthew Wilcox <willy@infradead.org>
cc: Miklos Szeredi <miklos@szeredi.hu>
cc: Trond Myklebust <trond.myklebust@hammerspace.com>
cc: Christoph Hellwig <hch@lst.de>
cc: Andrew Morton <akpm@linux-foundation.org>
cc: Alexander Viro <viro@zeniv.linux.org.uk>
cc: Christian Brauner <brauner@kernel.org>
cc: Jeff Layton <jlayton@kernel.org>
cc: linux-mm@kvack.org
cc: linux-fsdevel@vger.kernel.org
cc: netfs@lists.linux.dev
cc: v9fs@lists.linux.dev
cc: linux-afs@lists.infradead.org
cc: ceph-devel@vger.kernel.org
cc: linux-cifs@vger.kernel.org
cc: linux-nfs@vger.kernel.org
cc: devel@lists.orangefs.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-08-30 15:11:48 +02:00
Pankaj Raghav
ab95d23bab filemap: allocate mapping_min_order folios in the page cache
filemap_create_folio() and do_read_cache_folio() were always allocating
folio of order 0. __filemap_get_folio was trying to allocate higher
order folios when fgp_flags had higher order hint set but it will default
to order 0 folio if higher order memory allocation fails.

Supporting mapping_min_order implies that we guarantee each folio in the
page cache has at least an order of mapping_min_order. When adding new
folios to the page cache we must also ensure the index used is aligned to
the mapping_min_order as the page cache requires the index to be aligned
to the order of the folio.

Co-developed-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Pankaj Raghav <p.raghav@samsung.com>
Link: https://lore.kernel.org/r/20240822135018.1931258-3-kernel@pankajraghav.com
Tested-by: David Howells <dhowells@redhat.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Daniel Gomez <da.gomez@samsung.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-08-23 13:49:48 +02:00
Matthew Wilcox (Oracle)
84429b675b fs: Allow fine-grained control of folio sizes
We need filesystems to be able to communicate acceptable folio sizes
to the pagecache for a variety of uses (e.g. large block sizes).
Support a range of folio sizes between order-0 and order-31.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Co-developed-by: Pankaj Raghav <p.raghav@samsung.com>
Signed-off-by: Pankaj Raghav <p.raghav@samsung.com>
Link: https://lore.kernel.org/r/20240822135018.1931258-2-kernel@pankajraghav.com
Tested-by: David Howells <dhowells@redhat.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Daniel Gomez <da.gomez@samsung.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-08-23 13:49:48 +02:00
Al Viro
1da91ea87a introduce fd_file(), convert all accessors to it.
For any changes of struct fd representation we need to
turn existing accesses to fields into calls of wrappers.
Accesses to struct fd::flags are very few (3 in linux/file.h,
1 in net/socket.c, 3 in fs/overlayfs/file.c and 3 more in
explicit initializers).
	Those can be dealt with in the commit converting to
new layout; accesses to struct fd::file are too many for that.
	This commit converts (almost) all of f.file to
fd_file(f).  It's not entirely mechanical ('file' is used as
a member name more than just in struct fd) and it does not
even attempt to distinguish the uses in pointer context from
those in boolean context; the latter will be eventually turned
into a separate helper (fd_empty()).

	NOTE: mass conversion to fd_empty(), tempting as it
might be, is a bad idea; better do that piecewise in commit
that convert from fdget...() to CLASS(...).

[conflicts in fs/fhandle.c, kernel/bpf/syscall.c, mm/memcontrol.c
caught by git; fs/stat.c one got caught by git grep]
[fs/xattr.c conflict]

Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2024-08-12 22:00:43 -04:00
Matthew Wilcox (Oracle)
1da86618bd
fs: Convert aops->write_begin to take a folio
Convert all callers from working on a page to working on one page
of a folio (support for working on an entire folio can come later).
Removes a lot of folio->page->folio conversions.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-08-07 11:33:21 +02:00
Matthew Wilcox (Oracle)
a225800f32
fs: Convert aops->write_end to take a folio
Most callers have a folio, and most implementations operate on a folio,
so remove the conversion from folio->page->folio to fit through this
interface.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-08-07 11:32:02 +02:00
Linus Torvalds
fbc90c042c - 875fa64577da ("mm/hugetlb_vmemmap: fix race with speculative PFN
walkers") is known to cause a performance regression
   (https://lore.kernel.org/all/3acefad9-96e5-4681-8014-827d6be71c7a@linux.ibm.com/T/#mfa809800a7862fb5bdf834c6f71a3a5113eb83ff).
   Yu has a fix which I'll send along later via the hotfixes branch.
 
 - In the series "mm: Avoid possible overflows in dirty throttling" Jan
   Kara addresses a couple of issues in the writeback throttling code.
   These fixes are also targetted at -stable kernels.
 
 - Ryusuke Konishi's series "nilfs2: fix potential issues related to
   reserved inodes" does that.  This should actually be in the
   mm-nonmm-stable tree, along with the many other nilfs2 patches.  My bad.
 
 - More folio conversions from Kefeng Wang in the series "mm: convert to
   folio_alloc_mpol()"
 
 - Kemeng Shi has sent some cleanups to the writeback code in the series
   "Add helper functions to remove repeated code and improve readability of
   cgroup writeback"
 
 - Kairui Song has made the swap code a little smaller and a little
   faster in the series "mm/swap: clean up and optimize swap cache index".
 
 - In the series "mm/memory: cleanly support zeropage in
   vm_insert_page*(), vm_map_pages*() and vmf_insert_mixed()" David
   Hildenbrand has reworked the rather sketchy handling of the use of the
   zeropage in MAP_SHARED mappings.  I don't see any runtime effects here -
   more a cleanup/understandability/maintainablity thing.
 
 - Dev Jain has improved selftests/mm/va_high_addr_switch.c's handling of
   higher addresses, for aarch64.  The (poorly named) series is
   "Restructure va_high_addr_switch".
 
 - The core TLB handling code gets some cleanups and possible slight
   optimizations in Bang Li's series "Add update_mmu_tlb_range() to
   simplify code".
 
 - Jane Chu has improved the handling of our
   fake-an-unrecoverable-memory-error testing feature MADV_HWPOISON in the
   series "Enhance soft hwpoison handling and injection".
 
 - Jeff Johnson has sent a billion patches everywhere to add
   MODULE_DESCRIPTION() to everything.  Some landed in this pull.
 
 - In the series "mm: cleanup MIGRATE_SYNC_NO_COPY mode", Kefeng Wang has
   simplified migration's use of hardware-offload memory copying.
 
 - Yosry Ahmed performs more folio API conversions in his series "mm:
   zswap: trivial folio conversions".
 
 - In the series "large folios swap-in: handle refault cases first",
   Chuanhua Han inches us forward in the handling of large pages in the
   swap code.  This is a cleanup and optimization, working toward the end
   objective of full support of large folio swapin/out.
 
 - In the series "mm,swap: cleanup VMA based swap readahead window
   calculation", Huang Ying has contributed some cleanups and a possible
   fixlet to his VMA based swap readahead code.
 
 - In the series "add mTHP support for anonymous shmem" Baolin Wang has
   taught anonymous shmem mappings to use multisize THP.  By default this
   is a no-op - users must opt in vis sysfs controls.  Dramatic
   improvements in pagefault latency are realized.
 
 - David Hildenbrand has some cleanups to our remaining use of
   page_mapcount() in the series "fs/proc: move page_mapcount() to
   fs/proc/internal.h".
 
 - David also has some highmem accounting cleanups in the series
   "mm/highmem: don't track highmem pages manually".
 
 - Build-time fixes and cleanups from John Hubbard in the series
   "cleanups, fixes, and progress towards avoiding "make headers"".
 
 - Cleanups and consolidation of the core pagemap handling from Barry
   Song in the series "mm: introduce pmd|pte_needs_soft_dirty_wp helpers
   and utilize them".
 
 - Lance Yang's series "Reclaim lazyfree THP without splitting" has
   reduced the latency of the reclaim of pmd-mapped THPs under fairly
   common circumstances.  A 10x speedup is seen in a microbenchmark.
 
   It does this by punting to aother CPU but I guess that's a win unless
   all CPUs are pegged.
 
 - hugetlb_cgroup cleanups from Xiu Jianfeng in the series
   "mm/hugetlb_cgroup: rework on cftypes".
 
 - Miaohe Lin's series "Some cleanups for memory-failure" does just that
   thing.
 
 - Is anyone reading this stuff?  If so, email me!
 
 - Someone other than SeongJae has developed a DAMON feature in Honggyu
   Kim's series "DAMON based tiered memory management for CXL memory".
   This adds DAMON features which may be used to help determine the
   efficiency of our placement of CXL/PCIe attached DRAM.
 
 - DAMON user API centralization and simplificatio work in SeongJae
   Park's series "mm/damon: introduce DAMON parameters online commit
   function".
 
 - In the series "mm: page_type, zsmalloc and page_mapcount_reset()"
   David Hildenbrand does some maintenance work on zsmalloc - partially
   modernizing its use of pageframe fields.
 
 - Kefeng Wang provides more folio conversions in the series "mm: remove
   page_maybe_dma_pinned() and page_mkclean()".
 
 - More cleanup from David Hildenbrand, this time in the series
   "mm/memory_hotplug: use PageOffline() instead of PageReserved() for
   !ZONE_DEVICE".  It "enlightens memory hotplug more about PageOffline()
   pages" and permits the removal of some virtio-mem hacks.
 
 - Barry Song's series "mm: clarify folio_add_new_anon_rmap() and
   __folio_add_anon_rmap()" is a cleanup to the anon folio handling in
   preparation for mTHP (multisize THP) swapin.
 
 - Kefeng Wang's series "mm: improve clear and copy user folio"
   implements more folio conversions, this time in the area of large folio
   userspace copying.
 
 - The series "Docs/mm/damon/maintaier-profile: document a mailing tool
   and community meetup series" tells people how to get better involved
   with other DAMON developers.  From SeongJae Park.
 
 - A large series ("kmsan: Enable on s390") from Ilya Leoshkevich does
   that.
 
 - David Hildenbrand sends along more cleanups, this time against the
   migration code.  The series is "mm/migrate: move NUMA hinting fault
   folio isolation + checks under PTL".
 
 - Jan Kara has found quite a lot of strangenesses and minor errors in
   the readahead code.  He addresses this in the series "mm: Fix various
   readahead quirks".
 
 - SeongJae Park's series "selftests/damon: test DAMOS tried regions and
   {min,max}_nr_regions" adds features and addresses errors in DAMON's self
   testing code.
 
 - Gavin Shan has found a userspace-triggerable WARN in the pagecache
   code.  The series "mm/filemap: Limit page cache size to that supported
   by xarray" addresses this.  The series is marked cc:stable.
 
 - Chengming Zhou's series "mm/ksm: cmp_and_merge_page() optimizations
   and cleanup" cleans up and slightly optimizes KSM.
 
 - Roman Gushchin has separated the memcg-v1 and memcg-v2 code - lots of
   code motion.  The series (which also makes the memcg-v1 code
   Kconfigurable) are
 
   "mm: memcg: separate legacy cgroup v1 code and put under config
   option" and
   "mm: memcg: put cgroup v1-specific memcg data under CONFIG_MEMCG_V1"
 
 - Dan Schatzberg's series "Add swappiness argument to memory.reclaim"
   adds an additional feature to this cgroup-v2 control file.
 
 - The series "Userspace controls soft-offline pages" from Jiaqi Yan
   permits userspace to stop the kernel's automatic treatment of excessive
   correctable memory errors.  In order to permit userspace to monitor and
   handle this situation.
 
 - Kefeng Wang's series "mm: migrate: support poison recover from migrate
   folio" teaches the kernel to appropriately handle migration from
   poisoned source folios rather than simply panicing.
 
 - SeongJae Park's series "Docs/damon: minor fixups and improvements"
   does those things.
 
 - In the series "mm/zsmalloc: change back to per-size_class lock"
   Chengming Zhou improves zsmalloc's scalability and memory utilization.
 
 - Vivek Kasireddy's series "mm/gup: Introduce memfd_pin_folios() for
   pinning memfd folios" makes the GUP code use FOLL_PIN rather than bare
   refcount increments.  So these paes can first be moved aside if they
   reside in the movable zone or a CMA block.
 
 - Andrii Nakryiko has added a binary ioctl()-based API to /proc/pid/maps
   for much faster reading of vma information.  The series is "query VMAs
   from /proc/<pid>/maps".
 
 - In the series "mm: introduce per-order mTHP split counters" Lance Yang
   improves the kernel's presentation of developer information related to
   multisize THP splitting.
 
 - Michael Ellerman has developed the series "Reimplement huge pages
   without hugepd on powerpc (8xx, e500, book3s/64)".  This permits
   userspace to use all available huge page sizes.
 
 - In the series "revert unconditional slab and page allocator fault
   injection calls" Vlastimil Babka removes a performance-affecting and not
   very useful feature from slab fault injection.
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Merge tag 'mm-stable-2024-07-21-14-50' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:

 - In the series "mm: Avoid possible overflows in dirty throttling" Jan
   Kara addresses a couple of issues in the writeback throttling code.
   These fixes are also targetted at -stable kernels.

 - Ryusuke Konishi's series "nilfs2: fix potential issues related to
   reserved inodes" does that. This should actually be in the
   mm-nonmm-stable tree, along with the many other nilfs2 patches. My
   bad.

 - More folio conversions from Kefeng Wang in the series "mm: convert to
   folio_alloc_mpol()"

 - Kemeng Shi has sent some cleanups to the writeback code in the series
   "Add helper functions to remove repeated code and improve readability
   of cgroup writeback"

 - Kairui Song has made the swap code a little smaller and a little
   faster in the series "mm/swap: clean up and optimize swap cache
   index".

 - In the series "mm/memory: cleanly support zeropage in
   vm_insert_page*(), vm_map_pages*() and vmf_insert_mixed()" David
   Hildenbrand has reworked the rather sketchy handling of the use of
   the zeropage in MAP_SHARED mappings. I don't see any runtime effects
   here - more a cleanup/understandability/maintainablity thing.

 - Dev Jain has improved selftests/mm/va_high_addr_switch.c's handling
   of higher addresses, for aarch64. The (poorly named) series is
   "Restructure va_high_addr_switch".

 - The core TLB handling code gets some cleanups and possible slight
   optimizations in Bang Li's series "Add update_mmu_tlb_range() to
   simplify code".

 - Jane Chu has improved the handling of our
   fake-an-unrecoverable-memory-error testing feature MADV_HWPOISON in
   the series "Enhance soft hwpoison handling and injection".

 - Jeff Johnson has sent a billion patches everywhere to add
   MODULE_DESCRIPTION() to everything. Some landed in this pull.

 - In the series "mm: cleanup MIGRATE_SYNC_NO_COPY mode", Kefeng Wang
   has simplified migration's use of hardware-offload memory copying.

 - Yosry Ahmed performs more folio API conversions in his series "mm:
   zswap: trivial folio conversions".

 - In the series "large folios swap-in: handle refault cases first",
   Chuanhua Han inches us forward in the handling of large pages in the
   swap code. This is a cleanup and optimization, working toward the end
   objective of full support of large folio swapin/out.

 - In the series "mm,swap: cleanup VMA based swap readahead window
   calculation", Huang Ying has contributed some cleanups and a possible
   fixlet to his VMA based swap readahead code.

 - In the series "add mTHP support for anonymous shmem" Baolin Wang has
   taught anonymous shmem mappings to use multisize THP. By default this
   is a no-op - users must opt in vis sysfs controls. Dramatic
   improvements in pagefault latency are realized.

 - David Hildenbrand has some cleanups to our remaining use of
   page_mapcount() in the series "fs/proc: move page_mapcount() to
   fs/proc/internal.h".

 - David also has some highmem accounting cleanups in the series
   "mm/highmem: don't track highmem pages manually".

 - Build-time fixes and cleanups from John Hubbard in the series
   "cleanups, fixes, and progress towards avoiding "make headers"".

 - Cleanups and consolidation of the core pagemap handling from Barry
   Song in the series "mm: introduce pmd|pte_needs_soft_dirty_wp helpers
   and utilize them".

 - Lance Yang's series "Reclaim lazyfree THP without splitting" has
   reduced the latency of the reclaim of pmd-mapped THPs under fairly
   common circumstances. A 10x speedup is seen in a microbenchmark.

   It does this by punting to aother CPU but I guess that's a win unless
   all CPUs are pegged.

 - hugetlb_cgroup cleanups from Xiu Jianfeng in the series
   "mm/hugetlb_cgroup: rework on cftypes".

 - Miaohe Lin's series "Some cleanups for memory-failure" does just that
   thing.

 - Someone other than SeongJae has developed a DAMON feature in Honggyu
   Kim's series "DAMON based tiered memory management for CXL memory".
   This adds DAMON features which may be used to help determine the
   efficiency of our placement of CXL/PCIe attached DRAM.

 - DAMON user API centralization and simplificatio work in SeongJae
   Park's series "mm/damon: introduce DAMON parameters online commit
   function".

 - In the series "mm: page_type, zsmalloc and page_mapcount_reset()"
   David Hildenbrand does some maintenance work on zsmalloc - partially
   modernizing its use of pageframe fields.

 - Kefeng Wang provides more folio conversions in the series "mm: remove
   page_maybe_dma_pinned() and page_mkclean()".

 - More cleanup from David Hildenbrand, this time in the series
   "mm/memory_hotplug: use PageOffline() instead of PageReserved() for
   !ZONE_DEVICE". It "enlightens memory hotplug more about PageOffline()
   pages" and permits the removal of some virtio-mem hacks.

 - Barry Song's series "mm: clarify folio_add_new_anon_rmap() and
   __folio_add_anon_rmap()" is a cleanup to the anon folio handling in
   preparation for mTHP (multisize THP) swapin.

 - Kefeng Wang's series "mm: improve clear and copy user folio"
   implements more folio conversions, this time in the area of large
   folio userspace copying.

 - The series "Docs/mm/damon/maintaier-profile: document a mailing tool
   and community meetup series" tells people how to get better involved
   with other DAMON developers. From SeongJae Park.

 - A large series ("kmsan: Enable on s390") from Ilya Leoshkevich does
   that.

 - David Hildenbrand sends along more cleanups, this time against the
   migration code. The series is "mm/migrate: move NUMA hinting fault
   folio isolation + checks under PTL".

 - Jan Kara has found quite a lot of strangenesses and minor errors in
   the readahead code. He addresses this in the series "mm: Fix various
   readahead quirks".

 - SeongJae Park's series "selftests/damon: test DAMOS tried regions and
   {min,max}_nr_regions" adds features and addresses errors in DAMON's
   self testing code.

 - Gavin Shan has found a userspace-triggerable WARN in the pagecache
   code. The series "mm/filemap: Limit page cache size to that supported
   by xarray" addresses this. The series is marked cc:stable.

 - Chengming Zhou's series "mm/ksm: cmp_and_merge_page() optimizations
   and cleanup" cleans up and slightly optimizes KSM.

 - Roman Gushchin has separated the memcg-v1 and memcg-v2 code - lots of
   code motion. The series (which also makes the memcg-v1 code
   Kconfigurable) are "mm: memcg: separate legacy cgroup v1 code and put
   under config option" and "mm: memcg: put cgroup v1-specific memcg
   data under CONFIG_MEMCG_V1"

 - Dan Schatzberg's series "Add swappiness argument to memory.reclaim"
   adds an additional feature to this cgroup-v2 control file.

 - The series "Userspace controls soft-offline pages" from Jiaqi Yan
   permits userspace to stop the kernel's automatic treatment of
   excessive correctable memory errors. In order to permit userspace to
   monitor and handle this situation.

 - Kefeng Wang's series "mm: migrate: support poison recover from
   migrate folio" teaches the kernel to appropriately handle migration
   from poisoned source folios rather than simply panicing.

 - SeongJae Park's series "Docs/damon: minor fixups and improvements"
   does those things.

 - In the series "mm/zsmalloc: change back to per-size_class lock"
   Chengming Zhou improves zsmalloc's scalability and memory
   utilization.

 - Vivek Kasireddy's series "mm/gup: Introduce memfd_pin_folios() for
   pinning memfd folios" makes the GUP code use FOLL_PIN rather than
   bare refcount increments. So these paes can first be moved aside if
   they reside in the movable zone or a CMA block.

 - Andrii Nakryiko has added a binary ioctl()-based API to
   /proc/pid/maps for much faster reading of vma information. The series
   is "query VMAs from /proc/<pid>/maps".

 - In the series "mm: introduce per-order mTHP split counters" Lance
   Yang improves the kernel's presentation of developer information
   related to multisize THP splitting.

 - Michael Ellerman has developed the series "Reimplement huge pages
   without hugepd on powerpc (8xx, e500, book3s/64)". This permits
   userspace to use all available huge page sizes.

 - In the series "revert unconditional slab and page allocator fault
   injection calls" Vlastimil Babka removes a performance-affecting and
   not very useful feature from slab fault injection.

* tag 'mm-stable-2024-07-21-14-50' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (411 commits)
  mm/mglru: fix ineffective protection calculation
  mm/zswap: fix a white space issue
  mm/hugetlb: fix kernel NULL pointer dereference when migrating hugetlb folio
  mm/hugetlb: fix possible recursive locking detected warning
  mm/gup: clear the LRU flag of a page before adding to LRU batch
  mm/numa_balancing: teach mpol_to_str about the balancing mode
  mm: memcg1: convert charge move flags to unsigned long long
  alloc_tag: fix page_ext_get/page_ext_put sequence during page splitting
  lib: reuse page_ext_data() to obtain codetag_ref
  lib: add missing newline character in the warning message
  mm/mglru: fix overshooting shrinker memory
  mm/mglru: fix div-by-zero in vmpressure_calc_level()
  mm/kmemleak: replace strncpy() with strscpy()
  mm, page_alloc: put should_fail_alloc_page() back behing CONFIG_FAIL_PAGE_ALLOC
  mm, slab: put should_failslab() back behind CONFIG_SHOULD_FAILSLAB
  mm: ignore data-race in __swap_writepage
  hugetlbfs: ensure generic_hugetlb_get_unmapped_area() returns higher address than mmap_min_addr
  mm: shmem: rename mTHP shmem counters
  mm: swap_state: use folio_alloc_mpol() in __read_swap_cache_async()
  mm/migrate: putback split folios when numa hint migration fails
  ...
2024-07-21 17:15:46 -07:00
Linus Torvalds
4f40c636b2 NFS Client Updates for Linux 6.11
New Features:
   * Add support for large folios
   * Implement rpcrdma generic device removal notification
   * Add client support for attribute delegations
   * Use a LAYOUTRETURN during reboot recovery to report layoutstats and errors
   * Improve throughput for random buffered writes
   * Add NVMe support to pnfs/blocklayout
 
 Bugfixes:
   * Fix rpcrdma_reqs_reset()
   * Avoid soft lockups when using UDP
   * Fix an nfs/blocklayout premature PR key unregestration
   * Another fix for EXCHGID4_FLAG_USE_PNFS_DS for DS server
   * Do not extend writes to the entire folio
   * Pass explicit offset and count values to tracepoints
   * Fix a race to wake up sleeping SUNRPC sync tasks
   * Fix gss_status tracepoint output
 
 Cleanups:
   * Add missing MODULE_DESCRIPTION() macros
   * Add blocklayout / SCSI layout tracepoints
   * Remove asm-generic headers from xprtrdma verbs.c
   * Remove unused 'struct mnt_fhstatus'
   * Other delegation related cleanups
   * Other folio related cleanups
   * Other pNFS related cleanups
   * Other xprtrdma cleanups
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Merge tag 'nfs-for-6.11-1' of git://git.linux-nfs.org/projects/anna/linux-nfs

Pull NFS client updates from Anna Schumaker:
 "New Features:
   - Add support for large folios
   - Implement rpcrdma generic device removal notification
   - Add client support for attribute delegations
   - Use a LAYOUTRETURN during reboot recovery to report layoutstats
     and errors
   - Improve throughput for random buffered writes
   - Add NVMe support to pnfs/blocklayout

  Bugfixes:
   - Fix rpcrdma_reqs_reset()
   - Avoid soft lockups when using UDP
   - Fix an nfs/blocklayout premature PR key unregestration
   - Another fix for EXCHGID4_FLAG_USE_PNFS_DS for DS server
   - Do not extend writes to the entire folio
   - Pass explicit offset and count values to tracepoints
   - Fix a race to wake up sleeping SUNRPC sync tasks
   - Fix gss_status tracepoint output

  Cleanups:
   - Add missing MODULE_DESCRIPTION() macros
   - Add blocklayout / SCSI layout tracepoints
   - Remove asm-generic headers from xprtrdma verbs.c
   - Remove unused 'struct mnt_fhstatus'
   - Other delegation related cleanups
   - Other folio related cleanups
   - Other pNFS related cleanups
   - Other xprtrdma cleanups"

* tag 'nfs-for-6.11-1' of git://git.linux-nfs.org/projects/anna/linux-nfs: (63 commits)
  SUNRPC: Fixup gss_status tracepoint error output
  SUNRPC: Fix a race to wake a sync task
  nfs: split nfs_read_folio
  nfs: pass explicit offset/count to trace events
  nfs: do not extend writes to the entire folio
  nfs/blocklayout: add support for NVMe
  nfs: remove nfs_page_length
  nfs: remove the unused max_deviceinfo_size field from struct pnfs_layoutdriver_type
  nfs: don't reuse partially completed requests in nfs_lock_and_join_requests
  nfs: move nfs_wait_on_request to write.c
  nfs: fold nfs_page_group_lock_subrequests into nfs_lock_and_join_requests
  nfs: fold nfs_folio_find_and_lock_request into nfs_lock_and_join_requests
  nfs: simplify nfs_folio_find_and_lock_request
  nfs: remove nfs_folio_private_request
  nfs: remove dead code for the old swap over NFS implementation
  NFSv4.1 another fix for EXCHGID4_FLAG_USE_PNFS_DS for DS server
  nfs: Block on write congestion
  nfs: Properly initialize server->writeback
  nfs: Drop pointless check from nfs_commit_release_pages()
  nfs/blocklayout: SCSI layout trace points for reservation key reg/unreg
  ...
2024-07-18 17:17:30 -07:00
ZhangPeng
24be02a421 filemap: replace pte_offset_map() with pte_offset_map_nolock()
The vmf->ptl in filemap_fault_recheck_pte_none() is still set from
handle_pte_fault().  But at the same time, we did a pte_unmap(vmf->pte). 
After a pte_unmap(vmf->pte) unmap and rcu_read_unlock(), the page table
may be racily changed and vmf->ptl maybe fails to protect the actual page
table.  Fix this by replacing pte_offset_map() with
pte_offset_map_nolock().

As David said, the PTL pointer might be stale so if we continue to use
it infilemap_fault_recheck_pte_none(), it might trigger UAF.  Also, if
the PTL fails, the issue fixed by commit 58f327f2ce ("filemap: avoid
unnecessary major faults in filemap_fault()") might reappear.

Link: https://lkml.kernel.org/r/20240313012913.2395414-1-zhangpeng362@huawei.com
Fixes: 58f327f2ce ("filemap: avoid unnecessary major faults in filemap_fault()")
Signed-off-by: ZhangPeng <zhangpeng362@huawei.com>
Suggested-by: David Hildenbrand <david@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Nanyong Sun <sunnanyong@huawei.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Yin Fengwei <fengwei.yin@intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-09 15:41:10 -07:00
Matthew Wilcox (Oracle)
9aac777aaf filemap: Convert generic_perform_write() to support large folios
Modelled after the loop in iomap_write_iter(), copy larger chunks from
userspace if the filesystem has created large folios.

[hch: use mapping_max_folio_size to keep supporting file systems that do
 not support large folios]

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Shaun Tancheff <shaun.tancheff@hpe.com>
Tested-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2024-07-08 10:55:39 -04:00
Andrew Morton
8ef6fd0e9e Merge branch 'mm-hotfixes-stable' into mm-stable to pick up "mm: fix
crashes from deferred split racing folio migration", needed by "mm:
migrate: split folio_migrate_mapping()".
2024-07-06 11:44:41 -07:00
Nhat Pham
5a4d8944d6 cachestat: do not flush stats in recency check
syzbot detects that cachestat() is flushing stats, which can sleep, in its
RCU read section (see [1]).  This is done in the workingset_test_recent()
step (which checks if the folio's eviction is recent).

Move the stat flushing step to before the RCU read section of cachestat,
and skip stat flushing during the recency check.

[1]: https://lore.kernel.org/cgroups/000000000000f71227061bdf97e0@google.com/

Link: https://lkml.kernel.org/r/20240627201737.3506959-1-nphamcs@gmail.com
Fixes: b006847222 ("mm: workingset: move the stats flush into workingset_test_recent()")
Signed-off-by: Nhat Pham <nphamcs@gmail.com>
Reported-by: syzbot+b7f13b2d0cc156edf61a@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/cgroups/000000000000f71227061bdf97e0@google.com/
Debugged-by: Johannes Weiner <hannes@cmpxchg.org>
Suggested-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: David Hildenbrand <david@redhat.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Kairui Song <kasong@tencent.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Yosry Ahmed <yosryahmed@google.com>
Cc: <stable@vger.kernel.org>	[6.8+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03 22:40:37 -07:00
Gavin Shan
3390916aca mm/filemap: skip to create PMD-sized page cache if needed
On ARM64, HPAGE_PMD_ORDER is 13 when the base page size is 64KB.  The
PMD-sized page cache can't be supported by xarray as the following error
messages indicate.

------------[ cut here ]------------
WARNING: CPU: 35 PID: 7484 at lib/xarray.c:1025 xas_split_alloc+0xf8/0x128
Modules linked in: nft_fib_inet nft_fib_ipv4 nft_fib_ipv6 nft_fib  \
nft_reject_inet nf_reject_ipv4 nf_reject_ipv6 nft_reject nft_ct    \
nft_chain_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4    \
ip_set rfkill nf_tables nfnetlink vfat fat virtio_balloon drm      \
fuse xfs libcrc32c crct10dif_ce ghash_ce sha2_ce sha256_arm64      \
sha1_ce virtio_net net_failover virtio_console virtio_blk failover \
dimlib virtio_mmio
CPU: 35 PID: 7484 Comm: test Kdump: loaded Tainted: G W 6.10.0-rc5-gavin+ #9
Hardware name: QEMU KVM Virtual Machine, BIOS edk2-20240524-1.el9 05/24/2024
pstate: 83400005 (Nzcv daif +PAN -UAO +TCO +DIT -SSBS BTYPE=--)
pc : xas_split_alloc+0xf8/0x128
lr : split_huge_page_to_list_to_order+0x1c4/0x720
sp : ffff800087a4f6c0
x29: ffff800087a4f6c0 x28: ffff800087a4f720 x27: 000000001fffffff
x26: 0000000000000c40 x25: 000000000000000d x24: ffff00010625b858
x23: ffff800087a4f720 x22: ffffffdfc0780000 x21: 0000000000000000
x20: 0000000000000000 x19: ffffffdfc0780000 x18: 000000001ff40000
x17: 00000000ffffffff x16: 0000018000000000 x15: 51ec004000000000
x14: 0000e00000000000 x13: 0000000000002000 x12: 0000000000000020
x11: 51ec000000000000 x10: 51ece1c0ffff8000 x9 : ffffbeb961a44d28
x8 : 0000000000000003 x7 : ffffffdfc0456420 x6 : ffff0000e1aa6eb8
x5 : 20bf08b4fe778fca x4 : ffffffdfc0456420 x3 : 0000000000000c40
x2 : 000000000000000d x1 : 000000000000000c x0 : 0000000000000000
Call trace:
 xas_split_alloc+0xf8/0x128
 split_huge_page_to_list_to_order+0x1c4/0x720
 truncate_inode_partial_folio+0xdc/0x160
 truncate_inode_pages_range+0x1b4/0x4a8
 truncate_pagecache_range+0x84/0xa0
 xfs_flush_unmap_range+0x70/0x90 [xfs]
 xfs_file_fallocate+0xfc/0x4d8 [xfs]
 vfs_fallocate+0x124/0x2e8
 ksys_fallocate+0x4c/0xa0
 __arm64_sys_fallocate+0x24/0x38
 invoke_syscall.constprop.0+0x7c/0xd8
 do_el0_svc+0xb4/0xd0
 el0_svc+0x44/0x1d8
 el0t_64_sync_handler+0x134/0x150
 el0t_64_sync+0x17c/0x180

Fix it by skipping to allocate PMD-sized page cache when its size is
larger than MAX_PAGECACHE_ORDER.  For this specific case, we will fall to
regular path where the readahead window is determined by BDI's sysfs file
(read_ahead_kb).

Link: https://lkml.kernel.org/r/20240627003953.1262512-4-gshan@redhat.com
Fixes: 4687fdbb80 ("mm/filemap: Support VM_HUGEPAGE for file mappings")
Signed-off-by: Gavin Shan <gshan@redhat.com>
Suggested-by: David Hildenbrand <david@redhat.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Darrick J. Wong <djwong@kernel.org>
Cc: Don Dutile <ddutile@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: William Kucharski <william.kucharski@oracle.com>
Cc: Zhenyu Zhang <zhenyzha@redhat.com>
Cc: <stable@vger.kernel.org>	[5.18+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03 22:40:37 -07:00
Yang Shi
fa2690af57 mm: page_ref: remove folio_try_get_rcu()
The below bug was reported on a non-SMP kernel:

[  275.267158][ T4335] ------------[ cut here ]------------
[  275.267949][ T4335] kernel BUG at include/linux/page_ref.h:275!
[  275.268526][ T4335] invalid opcode: 0000 [#1] KASAN PTI
[  275.269001][ T4335] CPU: 0 PID: 4335 Comm: trinity-c3 Not tainted 6.7.0-rc4-00061-gefa7df3e3bb5 #1
[  275.269787][ T4335] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
[  275.270679][ T4335] RIP: 0010:try_get_folio (include/linux/page_ref.h:275 (discriminator 3) mm/gup.c:79 (discriminator 3))
[  275.272813][ T4335] RSP: 0018:ffffc90005dcf650 EFLAGS: 00010202
[  275.273346][ T4335] RAX: 0000000000000246 RBX: ffffea00066e0000 RCX: 0000000000000000
[  275.274032][ T4335] RDX: fffff94000cdc007 RSI: 0000000000000004 RDI: ffffea00066e0034
[  275.274719][ T4335] RBP: ffffea00066e0000 R08: 0000000000000000 R09: fffff94000cdc006
[  275.275404][ T4335] R10: ffffea00066e0037 R11: 0000000000000000 R12: 0000000000000136
[  275.276106][ T4335] R13: ffffea00066e0034 R14: dffffc0000000000 R15: ffffea00066e0008
[  275.276790][ T4335] FS:  00007fa2f9b61740(0000) GS:ffffffff89d0d000(0000) knlGS:0000000000000000
[  275.277570][ T4335] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  275.278143][ T4335] CR2: 00007fa2f6c00000 CR3: 0000000134b04000 CR4: 00000000000406f0
[  275.278833][ T4335] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  275.279521][ T4335] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[  275.280201][ T4335] Call Trace:
[  275.280499][ T4335]  <TASK>
[ 275.280751][ T4335] ? die (arch/x86/kernel/dumpstack.c:421 arch/x86/kernel/dumpstack.c:434 arch/x86/kernel/dumpstack.c:447)
[ 275.281087][ T4335] ? do_trap (arch/x86/kernel/traps.c:112 arch/x86/kernel/traps.c:153)
[ 275.281463][ T4335] ? try_get_folio (include/linux/page_ref.h:275 (discriminator 3) mm/gup.c:79 (discriminator 3))
[ 275.281884][ T4335] ? try_get_folio (include/linux/page_ref.h:275 (discriminator 3) mm/gup.c:79 (discriminator 3))
[ 275.282300][ T4335] ? do_error_trap (arch/x86/kernel/traps.c:174)
[ 275.282711][ T4335] ? try_get_folio (include/linux/page_ref.h:275 (discriminator 3) mm/gup.c:79 (discriminator 3))
[ 275.283129][ T4335] ? handle_invalid_op (arch/x86/kernel/traps.c:212)
[ 275.283561][ T4335] ? try_get_folio (include/linux/page_ref.h:275 (discriminator 3) mm/gup.c:79 (discriminator 3))
[ 275.283990][ T4335] ? exc_invalid_op (arch/x86/kernel/traps.c:264)
[ 275.284415][ T4335] ? asm_exc_invalid_op (arch/x86/include/asm/idtentry.h:568)
[ 275.284859][ T4335] ? try_get_folio (include/linux/page_ref.h:275 (discriminator 3) mm/gup.c:79 (discriminator 3))
[ 275.285278][ T4335] try_grab_folio (mm/gup.c:148)
[ 275.285684][ T4335] __get_user_pages (mm/gup.c:1297 (discriminator 1))
[ 275.286111][ T4335] ? __pfx___get_user_pages (mm/gup.c:1188)
[ 275.286579][ T4335] ? __pfx_validate_chain (kernel/locking/lockdep.c:3825)
[ 275.287034][ T4335] ? mark_lock (kernel/locking/lockdep.c:4656 (discriminator 1))
[ 275.287416][ T4335] __gup_longterm_locked (mm/gup.c:1509 mm/gup.c:2209)
[ 275.288192][ T4335] ? __pfx___gup_longterm_locked (mm/gup.c:2204)
[ 275.288697][ T4335] ? __pfx_lock_acquire (kernel/locking/lockdep.c:5722)
[ 275.289135][ T4335] ? __pfx___might_resched (kernel/sched/core.c:10106)
[ 275.289595][ T4335] pin_user_pages_remote (mm/gup.c:3350)
[ 275.290041][ T4335] ? __pfx_pin_user_pages_remote (mm/gup.c:3350)
[ 275.290545][ T4335] ? find_held_lock (kernel/locking/lockdep.c:5244 (discriminator 1))
[ 275.290961][ T4335] ? mm_access (kernel/fork.c:1573)
[ 275.291353][ T4335] process_vm_rw_single_vec+0x142/0x360
[ 275.291900][ T4335] ? __pfx_process_vm_rw_single_vec+0x10/0x10
[ 275.292471][ T4335] ? mm_access (kernel/fork.c:1573)
[ 275.292859][ T4335] process_vm_rw_core+0x272/0x4e0
[ 275.293384][ T4335] ? hlock_class (arch/x86/include/asm/bitops.h:227 arch/x86/include/asm/bitops.h:239 include/asm-generic/bitops/instrumented-non-atomic.h:142 kernel/locking/lockdep.c:228)
[ 275.293780][ T4335] ? __pfx_process_vm_rw_core+0x10/0x10
[ 275.294350][ T4335] process_vm_rw (mm/process_vm_access.c:284)
[ 275.294748][ T4335] ? __pfx_process_vm_rw (mm/process_vm_access.c:259)
[ 275.295197][ T4335] ? __task_pid_nr_ns (include/linux/rcupdate.h:306 (discriminator 1) include/linux/rcupdate.h:780 (discriminator 1) kernel/pid.c:504 (discriminator 1))
[ 275.295634][ T4335] __x64_sys_process_vm_readv (mm/process_vm_access.c:291)
[ 275.296139][ T4335] ? syscall_enter_from_user_mode (kernel/entry/common.c:94 kernel/entry/common.c:112)
[ 275.296642][ T4335] do_syscall_64 (arch/x86/entry/common.c:51 (discriminator 1) arch/x86/entry/common.c:82 (discriminator 1))
[ 275.297032][ T4335] ? __task_pid_nr_ns (include/linux/rcupdate.h:306 (discriminator 1) include/linux/rcupdate.h:780 (discriminator 1) kernel/pid.c:504 (discriminator 1))
[ 275.297470][ T4335] ? lockdep_hardirqs_on_prepare (kernel/locking/lockdep.c:4300 kernel/locking/lockdep.c:4359)
[ 275.297988][ T4335] ? do_syscall_64 (arch/x86/include/asm/cpufeature.h:171 arch/x86/entry/common.c:97)
[ 275.298389][ T4335] ? lockdep_hardirqs_on_prepare (kernel/locking/lockdep.c:4300 kernel/locking/lockdep.c:4359)
[ 275.298906][ T4335] ? do_syscall_64 (arch/x86/include/asm/cpufeature.h:171 arch/x86/entry/common.c:97)
[ 275.299304][ T4335] ? do_syscall_64 (arch/x86/include/asm/cpufeature.h:171 arch/x86/entry/common.c:97)
[ 275.299703][ T4335] ? do_syscall_64 (arch/x86/include/asm/cpufeature.h:171 arch/x86/entry/common.c:97)
[ 275.300115][ T4335] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:129)

This BUG is the VM_BUG_ON(!in_atomic() && !irqs_disabled()) assertion in
folio_ref_try_add_rcu() for non-SMP kernel.

The process_vm_readv() calls GUP to pin the THP. An optimization for
pinning THP instroduced by commit 57edfcfd34 ("mm/gup: accelerate thp
gup even for "pages != NULL"") calls try_grab_folio() to pin the THP,
but try_grab_folio() is supposed to be called in atomic context for
non-SMP kernel, for example, irq disabled or preemption disabled, due to
the optimization introduced by commit e286781d5f ("mm: speculative
page references").

The commit efa7df3e3b ("mm: align larger anonymous mappings on THP
boundaries") is not actually the root cause although it was bisected to.
It just makes the problem exposed more likely.

The follow up discussion suggested the optimization for non-SMP kernel
may be out-dated and not worth it anymore [1].  So removing the
optimization to silence the BUG.

However calling try_grab_folio() in GUP slow path actually is
unnecessary, so the following patch will clean this up.

[1] https://lore.kernel.org/linux-mm/821cf1d6-92b9-4ac4-bacc-d8f2364ac14f@paulmck-laptop/

Link: https://lkml.kernel.org/r/20240625205350.1777481-1-yang@os.amperecomputing.com
Fixes: 57edfcfd34 ("mm/gup: accelerate thp gup even for "pages != NULL"")
Signed-off-by: Yang Shi <yang@os.amperecomputing.com>
Reported-by: kernel test robot <oliver.sang@intel.com>
Tested-by: Oliver Sang <oliver.sang@intel.com>
Acked-by: Peter Xu <peterx@redhat.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Vivek Kasireddy <vivek.kasireddy@intel.com>
Cc: <stable@vger.kernel.org>	[6.6+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03 22:40:35 -07:00
Jan Kara
901a269ff3 filemap: fix page_cache_next_miss() when no hole found
page_cache_next_miss() should return value outside of the specified range
when no hole is found.  However currently it will return the last index
*in* the specified range confusing ondemand_readahead() to think there's a
hole in the searched range and upsetting readahead logic.

Link: https://lkml.kernel.org/r/20240625101909.12234-2-jack@suse.cz
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Tested-by: Zhang Peng <zhangpengpeng0808@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03 19:30:27 -07:00
David Hildenbrand
9bf46441ad mm/filemap: reinitialize folio->_mapcount directly
Let's get rid of the page_mapcount_reset() call and simply reinitialize
folio->_mapcount directly.

Link: https://lkml.kernel.org/r/20240529111904.2069608-6-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Tested-by: Sergey Senozhatsky <senozhatsky@chromium.org>	[zram/zsmalloc workloads]
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03 19:30:17 -07:00
Suren Baghdasaryan
9415983599 mm: fix xyz_noprof functions calling profiled functions
Grepping /proc/allocinfo for "noprof" reveals several xyz_noprof
functions, which means internally they are calling profiled functions. 
This should never happen as such calls move allocation charge from a
higher level location where it should be accounted for into these lower
level helpers.  Fix this by replacing profiled function calls with noprof
ones.

Link: https://lkml.kernel.org/r/20240531205350.3973009-1-surenb@google.com
Fixes: b951aaff50 ("mm: enable page allocation tagging")
Fixes: e26d8769da ("mempool: hook up to memory allocation profiling")
Fixes: 88ae5fb755 ("mm: vmalloc: enable memory allocation profiling")
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Reviewed-by: Kees Cook <kees@kernel.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-06-05 19:19:26 -07:00
Linus Torvalds
61307b7be4 The usual shower of singleton fixes and minor series all over MM,
documented (hopefully adequately) in the respective changelogs.  Notable
 series include:
 
 - Lucas Stach has provided some page-mapping
   cleanup/consolidation/maintainability work in the series "mm/treewide:
   Remove pXd_huge() API".
 
 - In the series "Allow migrate on protnone reference with
   MPOL_PREFERRED_MANY policy", Donet Tom has optimized mempolicy's
   MPOL_PREFERRED_MANY mode, yielding almost doubled performance in one
   test.
 
 - In their series "Memory allocation profiling" Kent Overstreet and
   Suren Baghdasaryan have contributed a means of determining (via
   /proc/allocinfo) whereabouts in the kernel memory is being allocated:
   number of calls and amount of memory.
 
 - Matthew Wilcox has provided the series "Various significant MM
   patches" which does a number of rather unrelated things, but in largely
   similar code sites.
 
 - In his series "mm: page_alloc: freelist migratetype hygiene" Johannes
   Weiner has fixed the page allocator's handling of migratetype requests,
   with resulting improvements in compaction efficiency.
 
 - In the series "make the hugetlb migration strategy consistent" Baolin
   Wang has fixed a hugetlb migration issue, which should improve hugetlb
   allocation reliability.
 
 - Liu Shixin has hit an I/O meltdown caused by readahead in a
   memory-tight memcg.  Addressed in the series "Fix I/O high when memory
   almost met memcg limit".
 
 - In the series "mm/filemap: optimize folio adding and splitting" Kairui
   Song has optimized pagecache insertion, yielding ~10% performance
   improvement in one test.
 
 - Baoquan He has cleaned up and consolidated the early zone
   initialization code in the series "mm/mm_init.c: refactor
   free_area_init_core()".
 
 - Baoquan has also redone some MM initializatio code in the series
   "mm/init: minor clean up and improvement".
 
 - MM helper cleanups from Christoph Hellwig in his series "remove
   follow_pfn".
 
 - More cleanups from Matthew Wilcox in the series "Various page->flags
   cleanups".
 
 - Vlastimil Babka has contributed maintainability improvements in the
   series "memcg_kmem hooks refactoring".
 
 - More folio conversions and cleanups in Matthew Wilcox's series
 
 	"Convert huge_zero_page to huge_zero_folio"
 	"khugepaged folio conversions"
 	"Remove page_idle and page_young wrappers"
 	"Use folio APIs in procfs"
 	"Clean up __folio_put()"
 	"Some cleanups for memory-failure"
 	"Remove page_mapping()"
 	"More folio compat code removal"
 
 - David Hildenbrand chipped in with "fs/proc/task_mmu: convert hugetlb
   functions to work on folis".
 
 - Code consolidation and cleanup work related to GUP's handling of
   hugetlbs in Peter Xu's series "mm/gup: Unify hugetlb, part 2".
 
 - Rick Edgecombe has developed some fixes to stack guard gaps in the
   series "Cover a guard gap corner case".
 
 - Jinjiang Tu has fixed KSM's behaviour after a fork+exec in the series
   "mm/ksm: fix ksm exec support for prctl".
 
 - Baolin Wang has implemented NUMA balancing for multi-size THPs.  This
   is a simple first-cut implementation for now.  The series is "support
   multi-size THP numa balancing".
 
 - Cleanups to vma handling helper functions from Matthew Wilcox in the
   series "Unify vma_address and vma_pgoff_address".
 
 - Some selftests maintenance work from Dev Jain in the series
   "selftests/mm: mremap_test: Optimizations and style fixes".
 
 - Improvements to the swapping of multi-size THPs from Ryan Roberts in
   the series "Swap-out mTHP without splitting".
 
 - Kefeng Wang has significantly optimized the handling of arm64's
   permission page faults in the series
 
 	"arch/mm/fault: accelerate pagefault when badaccess"
 	"mm: remove arch's private VM_FAULT_BADMAP/BADACCESS"
 
 - GUP cleanups from David Hildenbrand in "mm/gup: consistently call it
   GUP-fast".
 
 - hugetlb fault code cleanups from Vishal Moola in "Hugetlb fault path to
   use struct vm_fault".
 
 - selftests build fixes from John Hubbard in the series "Fix
   selftests/mm build without requiring "make headers"".
 
 - Memory tiering fixes/improvements from Ho-Ren (Jack) Chuang in the
   series "Improved Memory Tier Creation for CPUless NUMA Nodes".  Fixes
   the initialization code so that migration between different memory types
   works as intended.
 
 - David Hildenbrand has improved follow_pte() and fixed an errant driver
   in the series "mm: follow_pte() improvements and acrn follow_pte()
   fixes".
 
 - David also did some cleanup work on large folio mapcounts in his
   series "mm: mapcount for large folios + page_mapcount() cleanups".
 
 - Folio conversions in KSM in Alex Shi's series "transfer page to folio
   in KSM".
 
 - Barry Song has added some sysfs stats for monitoring multi-size THP's
   in the series "mm: add per-order mTHP alloc and swpout counters".
 
 - Some zswap cleanups from Yosry Ahmed in the series "zswap same-filled
   and limit checking cleanups".
 
 - Matthew Wilcox has been looking at buffer_head code and found the
   documentation to be lacking.  The series is "Improve buffer head
   documentation".
 
 - Multi-size THPs get more work, this time from Lance Yang.  His series
   "mm/madvise: enhance lazyfreeing with mTHP in madvise_free" optimizes
   the freeing of these things.
 
 - Kemeng Shi has added more userspace-visible writeback instrumentation
   in the series "Improve visibility of writeback".
 
 - Kemeng Shi then sent some maintenance work on top in the series "Fix
   and cleanups to page-writeback".
 
 - Matthew Wilcox reduces mmap_lock traffic in the anon vma code in the
   series "Improve anon_vma scalability for anon VMAs".  Intel's test bot
   reported an improbable 3x improvement in one test.
 
 - SeongJae Park adds some DAMON feature work in the series
 
 	"mm/damon: add a DAMOS filter type for page granularity access recheck"
 	"selftests/damon: add DAMOS quota goal test"
 
 - Also some maintenance work in the series
 
 	"mm/damon/paddr: simplify page level access re-check for pageout"
 	"mm/damon: misc fixes and improvements"
 
 - David Hildenbrand has disabled some known-to-fail selftests ni the
   series "selftests: mm: cow: flag vmsplice() hugetlb tests as XFAIL".
 
 - memcg metadata storage optimizations from Shakeel Butt in "memcg:
   reduce memory consumption by memcg stats".
 
 - DAX fixes and maintenance work from Vishal Verma in the series
   "dax/bus.c: Fixups for dax-bus locking".
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Merge tag 'mm-stable-2024-05-17-19-19' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull mm updates from Andrew Morton:
 "The usual shower of singleton fixes and minor series all over MM,
  documented (hopefully adequately) in the respective changelogs.
  Notable series include:

   - Lucas Stach has provided some page-mapping cleanup/consolidation/
     maintainability work in the series "mm/treewide: Remove pXd_huge()
     API".

   - In the series "Allow migrate on protnone reference with
     MPOL_PREFERRED_MANY policy", Donet Tom has optimized mempolicy's
     MPOL_PREFERRED_MANY mode, yielding almost doubled performance in
     one test.

   - In their series "Memory allocation profiling" Kent Overstreet and
     Suren Baghdasaryan have contributed a means of determining (via
     /proc/allocinfo) whereabouts in the kernel memory is being
     allocated: number of calls and amount of memory.

   - Matthew Wilcox has provided the series "Various significant MM
     patches" which does a number of rather unrelated things, but in
     largely similar code sites.

   - In his series "mm: page_alloc: freelist migratetype hygiene"
     Johannes Weiner has fixed the page allocator's handling of
     migratetype requests, with resulting improvements in compaction
     efficiency.

   - In the series "make the hugetlb migration strategy consistent"
     Baolin Wang has fixed a hugetlb migration issue, which should
     improve hugetlb allocation reliability.

   - Liu Shixin has hit an I/O meltdown caused by readahead in a
     memory-tight memcg. Addressed in the series "Fix I/O high when
     memory almost met memcg limit".

   - In the series "mm/filemap: optimize folio adding and splitting"
     Kairui Song has optimized pagecache insertion, yielding ~10%
     performance improvement in one test.

   - Baoquan He has cleaned up and consolidated the early zone
     initialization code in the series "mm/mm_init.c: refactor
     free_area_init_core()".

   - Baoquan has also redone some MM initializatio code in the series
     "mm/init: minor clean up and improvement".

   - MM helper cleanups from Christoph Hellwig in his series "remove
     follow_pfn".

   - More cleanups from Matthew Wilcox in the series "Various
     page->flags cleanups".

   - Vlastimil Babka has contributed maintainability improvements in the
     series "memcg_kmem hooks refactoring".

   - More folio conversions and cleanups in Matthew Wilcox's series:
	"Convert huge_zero_page to huge_zero_folio"
	"khugepaged folio conversions"
	"Remove page_idle and page_young wrappers"
	"Use folio APIs in procfs"
	"Clean up __folio_put()"
	"Some cleanups for memory-failure"
	"Remove page_mapping()"
	"More folio compat code removal"

   - David Hildenbrand chipped in with "fs/proc/task_mmu: convert
     hugetlb functions to work on folis".

   - Code consolidation and cleanup work related to GUP's handling of
     hugetlbs in Peter Xu's series "mm/gup: Unify hugetlb, part 2".

   - Rick Edgecombe has developed some fixes to stack guard gaps in the
     series "Cover a guard gap corner case".

   - Jinjiang Tu has fixed KSM's behaviour after a fork+exec in the
     series "mm/ksm: fix ksm exec support for prctl".

   - Baolin Wang has implemented NUMA balancing for multi-size THPs.
     This is a simple first-cut implementation for now. The series is
     "support multi-size THP numa balancing".

   - Cleanups to vma handling helper functions from Matthew Wilcox in
     the series "Unify vma_address and vma_pgoff_address".

   - Some selftests maintenance work from Dev Jain in the series
     "selftests/mm: mremap_test: Optimizations and style fixes".

   - Improvements to the swapping of multi-size THPs from Ryan Roberts
     in the series "Swap-out mTHP without splitting".

   - Kefeng Wang has significantly optimized the handling of arm64's
     permission page faults in the series
	"arch/mm/fault: accelerate pagefault when badaccess"
	"mm: remove arch's private VM_FAULT_BADMAP/BADACCESS"

   - GUP cleanups from David Hildenbrand in "mm/gup: consistently call
     it GUP-fast".

   - hugetlb fault code cleanups from Vishal Moola in "Hugetlb fault
     path to use struct vm_fault".

   - selftests build fixes from John Hubbard in the series "Fix
     selftests/mm build without requiring "make headers"".

   - Memory tiering fixes/improvements from Ho-Ren (Jack) Chuang in the
     series "Improved Memory Tier Creation for CPUless NUMA Nodes".
     Fixes the initialization code so that migration between different
     memory types works as intended.

   - David Hildenbrand has improved follow_pte() and fixed an errant
     driver in the series "mm: follow_pte() improvements and acrn
     follow_pte() fixes".

   - David also did some cleanup work on large folio mapcounts in his
     series "mm: mapcount for large folios + page_mapcount() cleanups".

   - Folio conversions in KSM in Alex Shi's series "transfer page to
     folio in KSM".

   - Barry Song has added some sysfs stats for monitoring multi-size
     THP's in the series "mm: add per-order mTHP alloc and swpout
     counters".

   - Some zswap cleanups from Yosry Ahmed in the series "zswap
     same-filled and limit checking cleanups".

   - Matthew Wilcox has been looking at buffer_head code and found the
     documentation to be lacking. The series is "Improve buffer head
     documentation".

   - Multi-size THPs get more work, this time from Lance Yang. His
     series "mm/madvise: enhance lazyfreeing with mTHP in madvise_free"
     optimizes the freeing of these things.

   - Kemeng Shi has added more userspace-visible writeback
     instrumentation in the series "Improve visibility of writeback".

   - Kemeng Shi then sent some maintenance work on top in the series
     "Fix and cleanups to page-writeback".

   - Matthew Wilcox reduces mmap_lock traffic in the anon vma code in
     the series "Improve anon_vma scalability for anon VMAs". Intel's
     test bot reported an improbable 3x improvement in one test.

   - SeongJae Park adds some DAMON feature work in the series
	"mm/damon: add a DAMOS filter type for page granularity access recheck"
	"selftests/damon: add DAMOS quota goal test"

   - Also some maintenance work in the series
	"mm/damon/paddr: simplify page level access re-check for pageout"
	"mm/damon: misc fixes and improvements"

   - David Hildenbrand has disabled some known-to-fail selftests ni the
     series "selftests: mm: cow: flag vmsplice() hugetlb tests as
     XFAIL".

   - memcg metadata storage optimizations from Shakeel Butt in "memcg:
     reduce memory consumption by memcg stats".

   - DAX fixes and maintenance work from Vishal Verma in the series
     "dax/bus.c: Fixups for dax-bus locking""

* tag 'mm-stable-2024-05-17-19-19' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (426 commits)
  memcg, oom: cleanup unused memcg_oom_gfp_mask and memcg_oom_order
  selftests/mm: hugetlb_madv_vs_map: avoid test skipping by querying hugepage size at runtime
  mm/hugetlb: add missing VM_FAULT_SET_HINDEX in hugetlb_wp
  mm/hugetlb: add missing VM_FAULT_SET_HINDEX in hugetlb_fault
  selftests: cgroup: add tests to verify the zswap writeback path
  mm: memcg: make alloc_mem_cgroup_per_node_info() return bool
  mm/damon/core: fix return value from damos_wmark_metric_value
  mm: do not update memcg stats for NR_{FILE/SHMEM}_PMDMAPPED
  selftests: cgroup: remove redundant enabling of memory controller
  Docs/mm/damon/maintainer-profile: allow posting patches based on damon/next tree
  Docs/mm/damon/maintainer-profile: change the maintainer's timezone from PST to PT
  Docs/mm/damon/design: use a list for supported filters
  Docs/admin-guide/mm/damon/usage: fix wrong schemes effective quota update command
  Docs/admin-guide/mm/damon/usage: fix wrong example of DAMOS filter matching sysfs file
  selftests/damon: classify tests for functionalities and regressions
  selftests/damon/_damon_sysfs: use 'is' instead of '==' for 'None'
  selftests/damon/_damon_sysfs: find sysfs mount point from /proc/mounts
  selftests/damon/_damon_sysfs: check errors from nr_schemes file reads
  mm/damon/core: initialize ->esz_bp from damos_quota_init_priv()
  selftests/damon: add a test for DAMOS quota goal
  ...
2024-05-19 09:21:03 -07:00
Kefeng Wang
ceca44991f mm: filemap: batch mm counter updating in filemap_map_pages()
Like copy_pte_range()/zap_pte_range(), make mm counter batch updating in
filemap_map_pages(), since folios type are same(MM_SHMEMPAGES or
MM_FILEPAGES) in filemap_map_pages(), only check the first folio type is
enough, the 'lat_pagefault -P 1 file' test from lmbench shows 12%
improvement, and the percpu_counter_add_batch() is gone from perf flame
graph.

Link: https://lkml.kernel.org/r/20240412064751.119015-3-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-05 17:53:36 -07:00
Kefeng Wang
1f2d8b4421 mm: move mm counter updating out of set_pte_range()
Patch series "mm: batch mm counter updating in filemap_map_pages()", v3.

Let's batch mm counter updating to accelerate filemap_map_pages().


This patch (of 2):

In order to support batch mm counter updating in filemap_map_pages(), move
mm counter updating out of set_pte_range(), the folios are file from
filemap, and distinguish folios by vmf->flags and vma->vm_flags from
another caller finish_fault().

Link: https://lkml.kernel.org/r/20240412064751.119015-1-wangkefeng.wang@huawei.com
Link: https://lkml.kernel.org/r/20240412064751.119015-2-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-05 17:53:36 -07:00
David Hildenbrand
f0376c7109 mm/filemap: use folio_mapcount() in filemap_unaccount_folio()
We want to limit the use of page_mapcount() to the places where it is
absolutely necessary.

Let's use folio_mapcount() instead of filemap_unaccount_folio().

No functional change intended, because we're only dealing with small
folios.

Link: https://lkml.kernel.org/r/20240409192301.907377-14-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: Hugh Dickins <hughd@google.com>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Richard Chang <richardycc@google.com>
Cc: Rich Felker <dalias@libc.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Yin Fengwei <fengwei.yin@intel.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-05 17:53:30 -07:00
David Howells
74e797d79c mm: Provide a means of invalidation without using launder_folio
Implement a replacement for launder_folio.  The key feature of
invalidate_inode_pages2() is that it locks each folio individually, unmaps
it to prevent mmap'd accesses interfering and calls the ->launder_folio()
address_space op to flush it.  This has problems: firstly, each folio is
written individually as one or more small writes; secondly, adjacent folios
cannot be added so easily into the laundry; thirdly, it's yet another op to
implement.

Instead, use the invalidate lock to cause anyone wanting to add a folio to
the inode to wait, then unmap all the folios if we have mmaps, then,
conditionally, use ->writepages() to flush any dirty data back and then
discard all pages.

The invalidate lock prevents ->read_iter(), ->write_iter() and faulting
through mmap all from adding pages for the duration.

This is then used from netfslib to handle the flusing in unbuffered and
direct writes.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Matthew Wilcox <willy@infradead.org>
cc: Miklos Szeredi <miklos@szeredi.hu>
cc: Trond Myklebust <trond.myklebust@hammerspace.com>
cc: Christoph Hellwig <hch@lst.de>
cc: Andrew Morton <akpm@linux-foundation.org>
cc: Alexander Viro <viro@zeniv.linux.org.uk>
cc: Christian Brauner <brauner@kernel.org>
cc: Jeff Layton <jlayton@kernel.org>
cc: linux-mm@kvack.org
cc: linux-fsdevel@vger.kernel.org
cc: netfs@lists.linux.dev
cc: v9fs@lists.linux.dev
cc: linux-afs@lists.infradead.org
cc: ceph-devel@vger.kernel.org
cc: linux-cifs@vger.kernel.org
cc: linux-nfs@vger.kernel.org
cc: devel@lists.orangefs.org
2024-05-01 18:07:06 +01:00
David Howells
2e9d7e4b98 mm: Remove the PG_fscache alias for PG_private_2
Remove the PG_fscache alias for PG_private_2 and use the latter directly.
Use of this flag for marking pages undergoing writing to the cache should
be considered deprecated and the folios should be marked dirty instead and
the write done in ->writepages().

Note that PG_private_2 itself should be considered deprecated and up for
future removal by the MM folks too.

Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
cc: Matthew Wilcox (Oracle) <willy@infradead.org>
cc: Ilya Dryomov <idryomov@gmail.com>
cc: Xiubo Li <xiubli@redhat.com>
cc: Steve French <sfrench@samba.org>
cc: Paulo Alcantara <pc@manguebit.com>
cc: Ronnie Sahlberg <ronniesahlberg@gmail.com>
cc: Shyam Prasad N <sprasad@microsoft.com>
cc: Tom Talpey <tom@talpey.com>
cc: Bharath SM <bharathsm@microsoft.com>
cc: Trond Myklebust <trond.myklebust@hammerspace.com>
cc: Anna Schumaker <anna@kernel.org>
cc: netfs@lists.linux.dev
cc: ceph-devel@vger.kernel.org
cc: linux-cifs@vger.kernel.org
cc: linux-nfs@vger.kernel.org
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
2024-04-29 15:01:42 +01:00
David Hildenbrand
0ae0b2b325 mm: use "GUP-fast" instead "fast GUP" in remaining comments
Let's fixup the remaining comments to consistently call that thing
"GUP-fast".  With this change, we consistently call it "GUP-fast".

Link: https://lkml.kernel.org/r/20240402125516.223131-4-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Cc: Peter Xu <peterx@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-25 20:56:41 -07:00
Kairui Song
6758c1128c mm/filemap: optimize filemap folio adding
Instead of doing multiple tree walks, do one optimism range check with
lock hold, and exit if raced with another insertion.  If a shadow exists,
check it with a new xas_get_order helper before releasing the lock to
avoid redundant tree walks for getting its order.

Drop the lock and do the allocation only if a split is needed.

In the best case, it only need to walk the tree once.  If it needs to
alloc and split, 3 walks are issued (One for first ranged conflict check
and order retrieving, one for the second check after allocation, one for
the insert after split).

Testing with 4K pages, in an 8G cgroup, with 16G brd as block device:

  echo 3 > /proc/sys/vm/drop_caches

  fio -name=cached --numjobs=16 --filename=/mnt/test.img \
    --buffered=1 --ioengine=mmap --rw=randread --time_based \
    --ramp_time=30s --runtime=5m --group_reporting

Before:
bw (  MiB/s): min= 1027, max= 3520, per=100.00%, avg=2445.02, stdev=18.90, samples=8691
iops        : min=263001, max=901288, avg=625924.36, stdev=4837.28, samples=8691

After (+7.3%):
bw (  MiB/s): min=  493, max= 3947, per=100.00%, avg=2625.56, stdev=25.74, samples=8651
iops        : min=126454, max=1010681, avg=672142.61, stdev=6590.48, samples=8651

Test result with THP (do a THP randread then switch to 4K page in hope it
issues a lot of splitting):

  echo 3 > /proc/sys/vm/drop_caches

  fio -name=cached --numjobs=16 --filename=/mnt/test.img \
      --buffered=1 --ioengine=mmap -thp=1 --readonly \
      --rw=randread --time_based --ramp_time=30s --runtime=10m \
      --group_reporting

  fio -name=cached --numjobs=16 --filename=/mnt/test.img \
      --buffered=1 --ioengine=mmap \
      --rw=randread --time_based --runtime=5s --group_reporting

Before:
bw (  KiB/s): min= 4141, max=14202, per=100.00%, avg=7935.51, stdev=96.85, samples=18976
iops        : min= 1029, max= 3548, avg=1979.52, stdev=24.23, samples=18976·

READ: bw=4545B/s (4545B/s), 4545B/s-4545B/s (4545B/s-4545B/s), io=64.0KiB (65.5kB), run=14419-14419msec

After (+12.5%):
bw (  KiB/s): min= 4611, max=15370, per=100.00%, avg=8928.74, stdev=105.17, samples=19146
iops        : min= 1151, max= 3842, avg=2231.27, stdev=26.29, samples=19146

READ: bw=4635B/s (4635B/s), 4635B/s-4635B/s (4635B/s-4635B/s), io=64.0KiB (65.5kB), run=14137-14137msec

The performance is better for both 4K (+7.5%) and THP (+12.5%) cached read.

Link: https://lkml.kernel.org/r/20240415171857.19244-5-ryncsn@gmail.com
Signed-off-by: Kairui Song <kasong@tencent.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-25 20:56:09 -07:00
Kairui Song
b2ebcf9d3d mm/filemap: clean up hugetlb exclusion code
__filemap_add_folio only has two callers, one never passes hugetlb folio
and one always passes in hugetlb folio.  So move the hugetlb related
cgroup charging out of it to make the code cleaner.

Link: https://lkml.kernel.org/r/20240415171857.19244-3-ryncsn@gmail.com
Signed-off-by: Kairui Song <kasong@tencent.com>
Acked-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-25 20:56:09 -07:00
Kairui Song
de60fd8dde mm/filemap: return early if failed to allocate memory for split
Patch series "mm/filemap: optimize folio adding and splitting", v4.

Currently, at least 3 tree walks are needed for filemap folio adding if
the folio is previously evicted.  One for getting the order of current
slot, one for ranged conflict check, and one for another order retrieving.
If a split is needed, more walks are needed.

This series is trying to merge these walks, and speed up
filemap_add_folio, I see a 7.5% - 12.5% performance gain for fio stress
test.

So instead of doing multiple tree walks, do one optimism range check with
lock hold, and exit if raced with another insertion.  If a shadow exists,
check it with a new xas_get_order helper before releasing the lock to
avoid redundant tree walks for getting its order.

Drop the lock and do the allocation only if a split is needed.

In the best case, it only need to walk the tree once.  If it needs to
alloc and split, 3 walks are issued (One for first ranged conflict check
and order retrieving, one for the second check after allocation, one for
the insert after split).

Testing with 4K pages, in an 8G cgroup, with 16G brd as block device:

  echo 3 > /proc/sys/vm/drop_caches

  fio -name=cached --numjobs=16 --filename=/mnt/test.img \
    --buffered=1 --ioengine=mmap --rw=randread --time_based \
    --ramp_time=30s --runtime=5m --group_reporting

Before:
bw (  MiB/s): min= 1027, max= 3520, per=100.00%, avg=2445.02, stdev=18.90, samples=8691
iops        : min=263001, max=901288, avg=625924.36, stdev=4837.28, samples=8691

After (+7.3%):
bw (  MiB/s): min=  493, max= 3947, per=100.00%, avg=2625.56, stdev=25.74, samples=8651
iops        : min=126454, max=1010681, avg=672142.61, stdev=6590.48, samples=8651

Test result with THP (do a THP randread then switch to 4K page in hope it
issues a lot of splitting):

  echo 3 > /proc/sys/vm/drop_caches

  fio -name=cached --numjobs=16 --filename=/mnt/test.img \
      --buffered=1 --ioengine=mmap -thp=1 --readonly \
      --rw=randread --time_based --ramp_time=30s --runtime=10m \
      --group_reporting

  fio -name=cached --numjobs=16 --filename=/mnt/test.img \
      --buffered=1 --ioengine=mmap \
      --rw=randread --time_based --runtime=5s --group_reporting

Before:
bw (  KiB/s): min= 4141, max=14202, per=100.00%, avg=7935.51, stdev=96.85, samples=18976
iops        : min= 1029, max= 3548, avg=1979.52, stdev=24.23, samples=18976·

READ: bw=4545B/s (4545B/s), 4545B/s-4545B/s (4545B/s-4545B/s), io=64.0KiB (65.5kB), run=14419-14419msec

After (+10.4%):
bw (  KiB/s): min= 4611, max=15370, per=100.00%, avg=8928.74, stdev=105.17, samples=19146
iops        : min= 1151, max= 3842, avg=2231.27, stdev=26.29, samples=19146

READ: bw=4635B/s (4635B/s), 4635B/s-4635B/s (4635B/s-4635B/s), io=64.0KiB (65.5kB), run=14137-14137msec

The performance is better for both 4K (+7.5%) and THP (+12.5%) cached read.


This patch (of 4):

xas_split_alloc could fail with NOMEM, and in such case, it should abort
early instead of keep going and fail the xas_split below.

Link: https://lkml.kernel.org/r/20240416071722.45997-1-ryncsn@gmail.com
Link: https://lkml.kernel.org/r/20240415171857.19244-1-ryncsn@gmail.com
Link: https://lkml.kernel.org/r/20240415171857.19244-2-ryncsn@gmail.com
Signed-off-by: Kairui Song <kasong@tencent.com>
Acked-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-25 20:56:09 -07:00
Liu Shixin
5c46d5319b mm/filemap: don't decrease mmap_miss when folio has workingset flag
If there are too many folios that are recently evicted in a file, then
they will probably continue to be evicted.  In such situation, there is no
positive effect to read-ahead this file since it is only a waste of IO.

The mmap_miss is increased in do_sync_mmap_readahead() and decreased in
both do_async_mmap_readahead() and filemap_map_pages().  In order to skip
read-ahead in above scenario, the mmap_miss have to increased exceed
MMAP_LOTSAMISS.  This can be done by stop decreased mmap_miss when folio
has workingset flag.  The async path is not to care because in above
scenario, it's hard to run into the async path.

[liushixin2@huawei.com: add comments]
  Link: https://lkml.kernel.org/r/20240326065026.1910584-1-liushixin2@huawei.com
Link: https://lkml.kernel.org/r/20240322093555.226789-3-liushixin2@huawei.com
Signed-off-by: Liu Shixin <liushixin2@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Jinjiang Tu <tujinjiang@huawei.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-25 20:56:07 -07:00
Suren Baghdasaryan
b951aaff50 mm: enable page allocation tagging
Redefine page allocators to record allocation tags upon their invocation. 
Instrument post_alloc_hook and free_pages_prepare to modify current
allocation tag.

[surenb@google.com: undo _noprof additions in the documentation]
  Link: https://lkml.kernel.org/r/20240326231453.1206227-3-surenb@google.com
Link: https://lkml.kernel.org/r/20240321163705.3067592-19-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Co-developed-by: Kent Overstreet <kent.overstreet@linux.dev>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Reviewed-by: Kees Cook <keescook@chromium.org>
Tested-by: Kees Cook <keescook@chromium.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Alex Gaynor <alex.gaynor@gmail.com>
Cc: Alice Ryhl <aliceryhl@google.com>
Cc: Andreas Hindborg <a.hindborg@samsung.com>
Cc: Benno Lossin <benno.lossin@proton.me>
Cc: "Björn Roy Baron" <bjorn3_gh@protonmail.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Gary Guo <gary@garyguo.net>
Cc: Miguel Ojeda <ojeda@kernel.org>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wedson Almeida Filho <wedsonaf@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-25 20:55:54 -07:00
Johannes Weiner
d5d39c707a mm: cachestat: fix two shmem bugs
When cachestat on shmem races with swapping and invalidation, there
are two possible bugs:

1) A swapin error can have resulted in a poisoned swap entry in the
   shmem inode's xarray. Calling get_shadow_from_swap_cache() on it
   will result in an out-of-bounds access to swapper_spaces[].

   Validate the entry with non_swap_entry() before going further.

2) When we find a valid swap entry in the shmem's inode, the shadow
   entry in the swapcache might not exist yet: swap IO is still in
   progress and we're before __remove_mapping; swapin, invalidation,
   or swapoff have removed the shadow from swapcache after we saw the
   shmem swap entry.

   This will send a NULL to workingset_test_recent(). The latter
   purely operates on pointer bits, so it won't crash - node 0, memcg
   ID 0, eviction timestamp 0, etc. are all valid inputs - but it's a
   bogus test. In theory that could result in a false "recently
   evicted" count.

   Such a false positive wouldn't be the end of the world. But for
   code clarity and (future) robustness, be explicit about this case.

   Bail on get_shadow_from_swap_cache() returning NULL.

Link: https://lkml.kernel.org/r/20240315095556.GC581298@cmpxchg.org
Fixes: cf264e1329 ("cachestat: implement cachestat syscall")
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reported-by: Chengming Zhou <chengming.zhou@linux.dev>	[Bug #1]
Reported-by: Jann Horn <jannh@google.com>		[Bug #2]
Reviewed-by: Chengming Zhou <chengming.zhou@linux.dev>
Reviewed-by: Nhat Pham <nphamcs@gmail.com>
Cc: <stable@vger.kernel.org>				[v6.5+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-03-26 11:07:20 -07:00
Linus Torvalds
902861e34c - Sumanth Korikkar has taught s390 to allocate hotplug-time page frames
from hotplugged memory rather than only from main memory.  Series
   "implement "memmap on memory" feature on s390".
 
 - More folio conversions from Matthew Wilcox in the series
 
 	"Convert memcontrol charge moving to use folios"
 	"mm: convert mm counter to take a folio"
 
 - Chengming Zhou has optimized zswap's rbtree locking, providing
   significant reductions in system time and modest but measurable
   reductions in overall runtimes.  The series is "mm/zswap: optimize the
   scalability of zswap rb-tree".
 
 - Chengming Zhou has also provided the series "mm/zswap: optimize zswap
   lru list" which provides measurable runtime benefits in some
   swap-intensive situations.
 
 - And Chengming Zhou further optimizes zswap in the series "mm/zswap:
   optimize for dynamic zswap_pools".  Measured improvements are modest.
 
 - zswap cleanups and simplifications from Yosry Ahmed in the series "mm:
   zswap: simplify zswap_swapoff()".
 
 - In the series "Add DAX ABI for memmap_on_memory", Vishal Verma has
   contributed several DAX cleanups as well as adding a sysfs tunable to
   control the memmap_on_memory setting when the dax device is hotplugged
   as system memory.
 
 - Johannes Weiner has added the large series "mm: zswap: cleanups",
   which does that.
 
 - More DAMON work from SeongJae Park in the series
 
 	"mm/damon: make DAMON debugfs interface deprecation unignorable"
 	"selftests/damon: add more tests for core functionalities and corner cases"
 	"Docs/mm/damon: misc readability improvements"
 	"mm/damon: let DAMOS feeds and tame/auto-tune itself"
 
 - In the series "mm/mempolicy: weighted interleave mempolicy and sysfs
   extension" Rakie Kim has developed a new mempolicy interleaving policy
   wherein we allocate memory across nodes in a weighted fashion rather
   than uniformly.  This is beneficial in heterogeneous memory environments
   appearing with CXL.
 
 - Christophe Leroy has contributed some cleanup and consolidation work
   against the ARM pagetable dumping code in the series "mm: ptdump:
   Refactor CONFIG_DEBUG_WX and check_wx_pages debugfs attribute".
 
 - Luis Chamberlain has added some additional xarray selftesting in the
   series "test_xarray: advanced API multi-index tests".
 
 - Muhammad Usama Anjum has reworked the selftest code to make its
   human-readable output conform to the TAP ("Test Anything Protocol")
   format.  Amongst other things, this opens up the use of third-party
   tools to parse and process out selftesting results.
 
 - Ryan Roberts has added fork()-time PTE batching of THP ptes in the
   series "mm/memory: optimize fork() with PTE-mapped THP".  Mainly
   targeted at arm64, this significantly speeds up fork() when the process
   has a large number of pte-mapped folios.
 
 - David Hildenbrand also gets in on the THP pte batching game in his
   series "mm/memory: optimize unmap/zap with PTE-mapped THP".  It
   implements batching during munmap() and other pte teardown situations.
   The microbenchmark improvements are nice.
 
 - And in the series "Transparent Contiguous PTEs for User Mappings" Ryan
   Roberts further utilizes arm's pte's contiguous bit ("contpte
   mappings").  Kernel build times on arm64 improved nicely.  Ryan's series
   "Address some contpte nits" provides some followup work.
 
 - In the series "mm/hugetlb: Restore the reservation" Breno Leitao has
   fixed an obscure hugetlb race which was causing unnecessary page faults.
   He has also added a reproducer under the selftest code.
 
 - In the series "selftests/mm: Output cleanups for the compaction test",
   Mark Brown did what the title claims.
 
 - Kinsey Ho has added the series "mm/mglru: code cleanup and refactoring".
 
 - Even more zswap material from Nhat Pham.  The series "fix and extend
   zswap kselftests" does as claimed.
 
 - In the series "Introduce cpu_dcache_is_aliasing() to fix DAX
   regression" Mathieu Desnoyers has cleaned up and fixed rather a mess in
   our handling of DAX on archiecctures which have virtually aliasing data
   caches.  The arm architecture is the main beneficiary.
 
 - Lokesh Gidra's series "per-vma locks in userfaultfd" provides dramatic
   improvements in worst-case mmap_lock hold times during certain
   userfaultfd operations.
 
 - Some page_owner enhancements and maintenance work from Oscar Salvador
   in his series
 
 	"page_owner: print stacks and their outstanding allocations"
 	"page_owner: Fixup and cleanup"
 
 - Uladzislau Rezki has contributed some vmalloc scalability improvements
   in his series "Mitigate a vmap lock contention".  It realizes a 12x
   improvement for a certain microbenchmark.
 
 - Some kexec/crash cleanup work from Baoquan He in the series "Split
   crash out from kexec and clean up related config items".
 
 - Some zsmalloc maintenance work from Chengming Zhou in the series
 
 	"mm/zsmalloc: fix and optimize objects/page migration"
 	"mm/zsmalloc: some cleanup for get/set_zspage_mapping()"
 
 - Zi Yan has taught the MM to perform compaction on folios larger than
   order=0.  This a step along the path to implementaton of the merging of
   large anonymous folios.  The series is named "Enable >0 order folio
   memory compaction".
 
 - Christoph Hellwig has done quite a lot of cleanup work in the
   pagecache writeback code in his series "convert write_cache_pages() to
   an iterator".
 
 - Some modest hugetlb cleanups and speedups in Vishal Moola's series
   "Handle hugetlb faults under the VMA lock".
 
 - Zi Yan has changed the page splitting code so we can split huge pages
   into sizes other than order-0 to better utilize large folios.  The
   series is named "Split a folio to any lower order folios".
 
 - David Hildenbrand has contributed the series "mm: remove
   total_mapcount()", a cleanup.
 
 - Matthew Wilcox has sought to improve the performance of bulk memory
   freeing in his series "Rearrange batched folio freeing".
 
 - Gang Li's series "hugetlb: parallelize hugetlb page init on boot"
   provides large improvements in bootup times on large machines which are
   configured to use large numbers of hugetlb pages.
 
 - Matthew Wilcox's series "PageFlags cleanups" does that.
 
 - Qi Zheng's series "minor fixes and supplement for ptdesc" does that
   also.  S390 is affected.
 
 - Cleanups to our pagemap utility functions from Peter Xu in his series
   "mm/treewide: Replace pXd_large() with pXd_leaf()".
 
 - Nico Pache has fixed a few things with our hugepage selftests in his
   series "selftests/mm: Improve Hugepage Test Handling in MM Selftests".
 
 - Also, of course, many singleton patches to many things.  Please see
   the individual changelogs for details.
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Merge tag 'mm-stable-2024-03-13-20-04' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:

 - Sumanth Korikkar has taught s390 to allocate hotplug-time page frames
   from hotplugged memory rather than only from main memory. Series
   "implement "memmap on memory" feature on s390".

 - More folio conversions from Matthew Wilcox in the series

	"Convert memcontrol charge moving to use folios"
	"mm: convert mm counter to take a folio"

 - Chengming Zhou has optimized zswap's rbtree locking, providing
   significant reductions in system time and modest but measurable
   reductions in overall runtimes. The series is "mm/zswap: optimize the
   scalability of zswap rb-tree".

 - Chengming Zhou has also provided the series "mm/zswap: optimize zswap
   lru list" which provides measurable runtime benefits in some
   swap-intensive situations.

 - And Chengming Zhou further optimizes zswap in the series "mm/zswap:
   optimize for dynamic zswap_pools". Measured improvements are modest.

 - zswap cleanups and simplifications from Yosry Ahmed in the series
   "mm: zswap: simplify zswap_swapoff()".

 - In the series "Add DAX ABI for memmap_on_memory", Vishal Verma has
   contributed several DAX cleanups as well as adding a sysfs tunable to
   control the memmap_on_memory setting when the dax device is
   hotplugged as system memory.

 - Johannes Weiner has added the large series "mm: zswap: cleanups",
   which does that.

 - More DAMON work from SeongJae Park in the series

	"mm/damon: make DAMON debugfs interface deprecation unignorable"
	"selftests/damon: add more tests for core functionalities and corner cases"
	"Docs/mm/damon: misc readability improvements"
	"mm/damon: let DAMOS feeds and tame/auto-tune itself"

 - In the series "mm/mempolicy: weighted interleave mempolicy and sysfs
   extension" Rakie Kim has developed a new mempolicy interleaving
   policy wherein we allocate memory across nodes in a weighted fashion
   rather than uniformly. This is beneficial in heterogeneous memory
   environments appearing with CXL.

 - Christophe Leroy has contributed some cleanup and consolidation work
   against the ARM pagetable dumping code in the series "mm: ptdump:
   Refactor CONFIG_DEBUG_WX and check_wx_pages debugfs attribute".

 - Luis Chamberlain has added some additional xarray selftesting in the
   series "test_xarray: advanced API multi-index tests".

 - Muhammad Usama Anjum has reworked the selftest code to make its
   human-readable output conform to the TAP ("Test Anything Protocol")
   format. Amongst other things, this opens up the use of third-party
   tools to parse and process out selftesting results.

 - Ryan Roberts has added fork()-time PTE batching of THP ptes in the
   series "mm/memory: optimize fork() with PTE-mapped THP". Mainly
   targeted at arm64, this significantly speeds up fork() when the
   process has a large number of pte-mapped folios.

 - David Hildenbrand also gets in on the THP pte batching game in his
   series "mm/memory: optimize unmap/zap with PTE-mapped THP". It
   implements batching during munmap() and other pte teardown
   situations. The microbenchmark improvements are nice.

 - And in the series "Transparent Contiguous PTEs for User Mappings"
   Ryan Roberts further utilizes arm's pte's contiguous bit ("contpte
   mappings"). Kernel build times on arm64 improved nicely. Ryan's
   series "Address some contpte nits" provides some followup work.

 - In the series "mm/hugetlb: Restore the reservation" Breno Leitao has
   fixed an obscure hugetlb race which was causing unnecessary page
   faults. He has also added a reproducer under the selftest code.

 - In the series "selftests/mm: Output cleanups for the compaction
   test", Mark Brown did what the title claims.

 - Kinsey Ho has added the series "mm/mglru: code cleanup and
   refactoring".

 - Even more zswap material from Nhat Pham. The series "fix and extend
   zswap kselftests" does as claimed.

 - In the series "Introduce cpu_dcache_is_aliasing() to fix DAX
   regression" Mathieu Desnoyers has cleaned up and fixed rather a mess
   in our handling of DAX on archiecctures which have virtually aliasing
   data caches. The arm architecture is the main beneficiary.

 - Lokesh Gidra's series "per-vma locks in userfaultfd" provides
   dramatic improvements in worst-case mmap_lock hold times during
   certain userfaultfd operations.

 - Some page_owner enhancements and maintenance work from Oscar Salvador
   in his series

	"page_owner: print stacks and their outstanding allocations"
	"page_owner: Fixup and cleanup"

 - Uladzislau Rezki has contributed some vmalloc scalability
   improvements in his series "Mitigate a vmap lock contention". It
   realizes a 12x improvement for a certain microbenchmark.

 - Some kexec/crash cleanup work from Baoquan He in the series "Split
   crash out from kexec and clean up related config items".

 - Some zsmalloc maintenance work from Chengming Zhou in the series

	"mm/zsmalloc: fix and optimize objects/page migration"
	"mm/zsmalloc: some cleanup for get/set_zspage_mapping()"

 - Zi Yan has taught the MM to perform compaction on folios larger than
   order=0. This a step along the path to implementaton of the merging
   of large anonymous folios. The series is named "Enable >0 order folio
   memory compaction".

 - Christoph Hellwig has done quite a lot of cleanup work in the
   pagecache writeback code in his series "convert write_cache_pages()
   to an iterator".

 - Some modest hugetlb cleanups and speedups in Vishal Moola's series
   "Handle hugetlb faults under the VMA lock".

 - Zi Yan has changed the page splitting code so we can split huge pages
   into sizes other than order-0 to better utilize large folios. The
   series is named "Split a folio to any lower order folios".

 - David Hildenbrand has contributed the series "mm: remove
   total_mapcount()", a cleanup.

 - Matthew Wilcox has sought to improve the performance of bulk memory
   freeing in his series "Rearrange batched folio freeing".

 - Gang Li's series "hugetlb: parallelize hugetlb page init on boot"
   provides large improvements in bootup times on large machines which
   are configured to use large numbers of hugetlb pages.

 - Matthew Wilcox's series "PageFlags cleanups" does that.

 - Qi Zheng's series "minor fixes and supplement for ptdesc" does that
   also. S390 is affected.

 - Cleanups to our pagemap utility functions from Peter Xu in his series
   "mm/treewide: Replace pXd_large() with pXd_leaf()".

 - Nico Pache has fixed a few things with our hugepage selftests in his
   series "selftests/mm: Improve Hugepage Test Handling in MM
   Selftests".

 - Also, of course, many singleton patches to many things. Please see
   the individual changelogs for details.

* tag 'mm-stable-2024-03-13-20-04' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (435 commits)
  mm/zswap: remove the memcpy if acomp is not sleepable
  crypto: introduce: acomp_is_async to expose if comp drivers might sleep
  memtest: use {READ,WRITE}_ONCE in memory scanning
  mm: prohibit the last subpage from reusing the entire large folio
  mm: recover pud_leaf() definitions in nopmd case
  selftests/mm: skip the hugetlb-madvise tests on unmet hugepage requirements
  selftests/mm: skip uffd hugetlb tests with insufficient hugepages
  selftests/mm: dont fail testsuite due to a lack of hugepages
  mm/huge_memory: skip invalid debugfs new_order input for folio split
  mm/huge_memory: check new folio order when split a folio
  mm, vmscan: retry kswapd's priority loop with cache_trim_mode off on failure
  mm: add an explicit smp_wmb() to UFFDIO_CONTINUE
  mm: fix list corruption in put_pages_list
  mm: remove folio from deferred split list before uncharging it
  filemap: avoid unnecessary major faults in filemap_fault()
  mm,page_owner: drop unnecessary check
  mm,page_owner: check for null stack_record before bumping its refcount
  mm: swap: fix race between free_swap_and_cache() and swapoff()
  mm/treewide: align up pXd_leaf() retval across archs
  mm/treewide: drop pXd_large()
  ...
2024-03-14 17:43:30 -07:00
Linus Torvalds
babbcc0232 New code for 6.9:
* Online Repair;
   ** New ondisk structures being repaired.
      - Inode's mode field by trying to obtain file type value from the a
        directory entry.
      - Quota counters.
      - Link counts of inodes.
      - FS summary counters.
      - rmap btrees.
        Support for in-memory btrees has been added to support repair of rmap
        btrees.
   ** Misc changes
      - Report corruption of metadata to the health tracking subsystem.
      - Enable indirect health reporting when resources are scarce.
      - Reduce memory usage while reparing refcount btree.
      - Extend "Bmap update" intent item to support atomic extent swapping on
        the realtime device.
      - Extend "Bmap update" intent item to support extended attribute fork and
        unwritten extents.
   ** Code cleanups
      - Bmap log intent.
      - Btree block pointer checking.
      - Btree readahead.
      - Buffer target.
      - Symbolic link code.
   * Remove mrlock wrapper around the rwsem.
   * Convert all the GFP_NOFS flag usages to use the scoped
     memalloc_nofs_save() API instead of direct calls with the GFP_NOFS.
   * Refactor and simplify xfile abstraction. Lower level APIs in
     shmem.c are required to be exported in order to achieve this.
   * Skip checking alignment constraints for inode chunk allocations when block
     size is larger than inode chunk size.
   * Do not submit delwri buffers collected during log recovery when an error
     has been encountered.
   * Fix SEEK_HOLE/DATA for file regions which have active COW extents.
   * Fix lock order inversion when executing error handling path during
     shrinking a filesystem.
   * Remove duplicate ifdefs.
 
 Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
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Merge tag 'xfs-6.9-merge-8' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux

Pull xfs updates from Chandan Babu:

 - Online repair updates:
    - More ondisk structures being repaired:
        - Inode's mode field by trying to obtain file type value from
          the a directory entry
        - Quota counters
        - Link counts of inodes
        - FS summary counters
        - Support for in-memory btrees has been added to support repair
          of rmap btrees
    - Misc changes:
        - Report corruption of metadata to the health tracking subsystem
        - Enable indirect health reporting when resources are scarce
        - Reduce memory usage while repairing refcount btree
        - Extend "Bmap update" intent item to support atomic extent
          swapping on the realtime device
        - Extend "Bmap update" intent item to support extended attribute
          fork and unwritten extents
    - Code cleanups:
        - Bmap log intent
        - Btree block pointer checking
        - Btree readahead
        - Buffer target
        - Symbolic link code

 - Remove mrlock wrapper around the rwsem

 - Convert all the GFP_NOFS flag usages to use the scoped
   memalloc_nofs_save() API instead of direct calls with the GFP_NOFS

 - Refactor and simplify xfile abstraction. Lower level APIs in shmem.c
   are required to be exported in order to achieve this

 - Skip checking alignment constraints for inode chunk allocations when
   block size is larger than inode chunk size

 - Do not submit delwri buffers collected during log recovery when an
   error has been encountered

 - Fix SEEK_HOLE/DATA for file regions which have active COW extents

 - Fix lock order inversion when executing error handling path during
   shrinking a filesystem

 - Remove duplicate ifdefs

* tag 'xfs-6.9-merge-8' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: (183 commits)
  xfs: shrink failure needs to hold AGI buffer
  mm/shmem.c: Use new form of *@param in kernel-doc
  kernel-doc: Add unary operator * to $type_param_ref
  xfs: use kvfree() in xlog_cil_free_logvec()
  xfs: xfs_btree_bload_prep_block() should use __GFP_NOFAIL
  xfs: fix scrub stats file permissions
  xfs: fix log recovery erroring out on refcount recovery failure
  xfs: move symlink target write function to libxfs
  xfs: move remote symlink target read function to libxfs
  xfs: move xfs_symlink_remote.c declarations to xfs_symlink_remote.h
  xfs: xfs_bmap_finish_one should map unwritten extents properly
  xfs: support deferred bmap updates on the attr fork
  xfs: support recovering bmap intent items targetting realtime extents
  xfs: add a realtime flag to the bmap update log redo items
  xfs: add a xattr_entry helper
  xfs: fix xfs_bunmapi to allow unmapping of partial rt extents
  xfs: move xfs_bmap_defer_add to xfs_bmap_item.c
  xfs: reuse xfs_bmap_update_cancel_item
  xfs: add a bi_entry helper
  xfs: remove xfs_trans_set_bmap_flags
  ...
2024-03-13 13:52:24 -07:00
Linus Torvalds
7ea65c89d8 vfs-6.9.misc
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Merge tag 'vfs-6.9.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

Pull misc vfs updates from Christian Brauner:
 "Misc features, cleanups, and fixes for vfs and individual filesystems.

  Features:

   - Support idmapped mounts for hugetlbfs.

   - Add RWF_NOAPPEND flag for pwritev2(). This allows us to fix a bug
     where the passed offset is ignored if the file is O_APPEND. The new
     flag allows a caller to enforce that the offset is honored to
     conform to posix even if the file was opened in append mode.

   - Move i_mmap_rwsem in struct address_space to avoid false sharing
     between i_mmap and i_mmap_rwsem.

   - Convert efs, qnx4, and coda to use the new mount api.

   - Add a generic is_dot_dotdot() helper that's used by various
     filesystems and the VFS code instead of open-coding it multiple
     times.

   - Recently we've added stable offsets which allows stable ordering
     when iterating directories exported through NFS on e.g., tmpfs
     filesystems. Originally an xarray was used for the offset map but
     that caused slab fragmentation issues over time. This switches the
     offset map to the maple tree which has a dense mode that handles
     this scenario a lot better. Includes tests.

   - Finally merge the case-insensitive improvement series Gabriel has
     been working on for a long time. This cleanly propagates case
     insensitive operations through ->s_d_op which in turn allows us to
     remove the quite ugly generic_set_encrypted_ci_d_ops() operations.
     It also improves performance by trying a case-sensitive comparison
     first and then fallback to case-insensitive lookup if that fails.
     This also fixes a bug where overlayfs would be able to be mounted
     over a case insensitive directory which would lead to all sort of
     odd behaviors.

  Cleanups:

   - Make file_dentry() a simple accessor now that ->d_real() is
     simplified because of the backing file work we did the last two
     cycles.

   - Use the dedicated file_mnt_idmap helper in ntfs3.

   - Use smp_load_acquire/store_release() in the i_size_read/write
     helpers and thus remove the hack to handle i_size reads in the
     filemap code.

   - The SLAB_MEM_SPREAD is a nop now. Remove it from various places in
     fs/

   - It's no longer necessary to perform a second built-in initramfs
     unpack call because we retain the contents of the previous
     extraction. Remove it.

   - Now that we have removed various allocators kfree_rcu() always
     works with kmem caches and kmalloc(). So simplify various places
     that only use an rcu callback in order to handle the kmem cache
     case.

   - Convert the pipe code to use a lockdep comparison function instead
     of open-coding the nesting making lockdep validation easier.

   - Move code into fs-writeback.c that was located in a header but can
     be made static as it's only used in that one file.

   - Rewrite the alignment checking iterators for iovec and bvec to be
     easier to read, and also significantly more compact in terms of
     generated code. This saves 270 bytes of text on x86-64 (with
     clang-18) and 224 bytes on arm64 (with gcc-13). In profiles it also
     saves a bit of time for the same workload.

   - Switch various places to use KMEM_CACHE instead of
     kmem_cache_create().

   - Use inode_set_ctime_to_ts() in inode_set_ctime_current()

   - Use kzalloc() in name_to_handle_at() to avoid kernel infoleak.

   - Various smaller cleanups for eventfds.

  Fixes:

   - Fix various comments and typos, and unneeded initializations.

   - Fix stack allocation hack for clang in the select code.

   - Improve dump_mapping() debug code on a best-effort basis.

   - Fix build errors in various selftests.

   - Avoid wrap-around instrumentation in various places.

   - Don't allow user namespaces without an idmapping to be used for
     idmapped mounts.

   - Fix sysv sb_read() call.

   - Fix fallback implementation of the get_name() export operation"

* tag 'vfs-6.9.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (70 commits)
  hugetlbfs: support idmapped mounts
  qnx4: convert qnx4 to use the new mount api
  fs: use inode_set_ctime_to_ts to set inode ctime to current time
  libfs: Drop generic_set_encrypted_ci_d_ops
  ubifs: Configure dentry operations at dentry-creation time
  f2fs: Configure dentry operations at dentry-creation time
  ext4: Configure dentry operations at dentry-creation time
  libfs: Add helper to choose dentry operations at mount-time
  libfs: Merge encrypted_ci_dentry_ops and ci_dentry_ops
  fscrypt: Drop d_revalidate once the key is added
  fscrypt: Drop d_revalidate for valid dentries during lookup
  fscrypt: Factor out a helper to configure the lookup dentry
  ovl: Always reject mounting over case-insensitive directories
  libfs: Attempt exact-match comparison first during casefolded lookup
  efs: remove SLAB_MEM_SPREAD flag usage
  jfs: remove SLAB_MEM_SPREAD flag usage
  minix: remove SLAB_MEM_SPREAD flag usage
  openpromfs: remove SLAB_MEM_SPREAD flag usage
  proc: remove SLAB_MEM_SPREAD flag usage
  qnx6: remove SLAB_MEM_SPREAD flag usage
  ...
2024-03-11 09:38:17 -07:00
ZhangPeng
58f327f2ce filemap: avoid unnecessary major faults in filemap_fault()
A major fault occurred when using mlockall(MCL_CURRENT | MCL_FUTURE) in
application, which leading to an unexpected issue[1].

This is caused by temporarily cleared PTE during a read+clear/modify/write
update of the PTE, eg, do_numa_page()/change_pte_range().

For the data segment of the user-mode program, the global variable area is
a private mapping.  After the pagecache is loaded, the private anonymous
page is generated after the COW is triggered.  Mlockall can lock COW pages
(anonymous pages), but the original file pages cannot be locked and may be
reclaimed.  If the global variable (private anon page) is accessed when
vmf->pte is zeroed in numa fault, a file page fault will be triggered.  At
this time, the original private file page may have been reclaimed.  If the
page cache is not available at this time, a major fault will be triggered
and the file will be read, causing additional overhead.

This issue affects our traffic analysis service.  The inbound traffic is
heavy.  If a major fault occurs, the I/O schedule is triggered and the
original I/O is suspended.  Generally, the I/O schedule is 0.7 ms.  If
other applications are operating disks, the system needs to wait for more
than 10 ms.  However, the inbound traffic is heavy and the NIC buffer is
small.  As a result, packet loss occurs.  But the traffic analysis service
can't tolerate packet loss.

Fix this by holding PTL and rechecking the PTE in filemap_fault() before
triggering a major fault.  We do this check only if vma is VM_LOCKED to
reduce the performance impact in common scenarios.

In our product environment, there were 7 major faults every 12 hours. 
After the patch is applied, no major fault have been triggered.

Testing file page read and write page fault performance in ext4 and
ramdisk using will-it-scale[2] on a x86 physical machine.  The data is the
average change compared with the mainline after the patch is applied.  The
test results are within the range of fluctuation.  We do this check only
if vma is VM_LOCKED, therefore, no performance regressions is caused for
most common cases.

The test results are as follows:
                          processes processes_idle  threads threads_idle
ext4    private file write:  0.22%    0.26%           1.21%  -0.15%
ext4    private file  read:  0.03%    1.00%           1.39%   0.34%
ext4    shared  file write: -0.50%   -0.02%          -0.14%  -0.02%
ramdisk private file write:  0.07%    0.02%           0.53%   0.04%
ramdisk private file  read:  0.01%    1.60%          -0.32%  -0.02%

[1] https://lore.kernel.org/linux-mm/9e62fd9a-bee0-52bf-50a7-498fa17434ee@huawei.com/
[2] https://github.com/antonblanchard/will-it-scale/

Link: https://lkml.kernel.org/r/20240306083809.1236634-1-zhangpeng362@huawei.com
Signed-off-by: ZhangPeng <zhangpeng362@huawei.com>
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Suggested-by: "Huang, Ying" <ying.huang@intel.com>
Suggested-by: David Hildenbrand <david@redhat.com>
Reviewed-by: "Huang, Ying" <ying.huang@intel.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-03-06 13:04:20 -08:00
Matthew Wilcox (Oracle)
8897277acf mm: support order-1 folios in the page cache
Folios of order 1 have no space to store the deferred list.  This is not a
problem for the page cache as file-backed folios are never placed on the
deferred list.  All we need to do is prevent the core MM from touching the
deferred list for order 1 folios and remove the code which prevented us
from allocating order 1 folios.

Link: https://lore.kernel.org/linux-mm/90344ea7-4eec-47ee-5996-0c22f42d6a6a@google.com/
Link: https://lkml.kernel.org/r/20240226205534.1603748-3-zi.yan@sent.com
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Zi Yan <ziy@nvidia.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Michal Koutny <mkoutny@suse.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Yu Zhao <yuzhao@google.com>
Cc: Zach O'Keefe <zokeefe@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-03-04 17:01:19 -08:00
Andrew Morton
1f1183c4c0 merge mm-hotfixes-stable into mm-nonmm-stable to pick up stackdepot changes 2024-02-23 17:28:43 -08:00
Nhat Pham
3a75cb05d5 mm: cachestat: fix folio read-after-free in cache walk
In cachestat, we access the folio from the page cache's xarray to compute
its page offset, and check for its dirty and writeback flags.  However, we
do not hold a reference to the folio before performing these actions,
which means the folio can concurrently be released and reused as another
folio/page/slab.

Get around this altogether by just using xarray's existing machinery for
the folio page offsets and dirty/writeback states.

This changes behavior for tmpfs files to now always report zeroes in their
dirty and writeback counters.  This is okay as tmpfs doesn't follow
conventional writeback cache behavior: its pages get "cleaned" during
swapout, after which they're no longer resident etc.

Link: https://lkml.kernel.org/r/20240220153409.GA216065@cmpxchg.org
Fixes: cf264e1329 ("cachestat: implement cachestat syscall")
Reported-by: Jann Horn <jannh@google.com>
Suggested-by: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Nhat Pham <nphamcs@gmail.com>
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Tested-by: Jann Horn <jannh@google.com>
Cc: <stable@vger.kernel.org>	[6.4+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-23 17:27:13 -08:00
Matthew Wilcox (Oracle)
5662400a9a mm: add pfn_swap_entry_folio()
Patch series "mm: convert mm counter to take a folio", v3.

Make sure all mm_counter() and mm_counter_file() callers have a folio,
then convert mm counter functions to take a folio, which saves some
compound_head() calls.


This patch (of 10):  

Thanks to the compound_head() hidden inside PageLocked(), this saves a
call to compound_head() over calling page_folio(pfn_swap_entry_to_page())

Link: https://lkml.kernel.org/r/20240111152429.3374566-1-willy@infradead.org
Link: https://lkml.kernel.org/r/20240111152429.3374566-2-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-21 16:00:03 -08:00
Hongbo Li
6212eb4d7a mm/filemap: avoid type conversion
The return type of function folio_test_hugetlb is bool type, there is no
need to assign it to an integer type.

Link: https://lkml.kernel.org/r/20240108044815.3291487-1-lihongbo22@huawei.com
Signed-off-by: Hongbo Li <lihongbo22@huawei.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-21 16:00:02 -08:00
Christoph Hellwig
b64e74e95a mm: move mapping_set_update out of <linux/swap.h>
mapping_set_update is only used inside mm/.  Move mapping_set_update to
mm/internal.h and turn it into an inline function instead of a macro.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
2024-02-21 11:36:50 +05:30
Baokun Li
4b944f8ef9 Revert "mm/filemap: avoid buffered read/write race to read inconsistent data"
This reverts commit e2c27b803b ("mm/filemap: avoid buffered read/write
race to read inconsistent data"). After making the i_size_read/write
helpers be smp_load_acquire/store_release(), it is already guaranteed that
changes to page contents are visible before we see increased inode size,
so the extra smp_rmb() in filemap_read() can be removed.

Signed-off-by: Baokun Li <libaokun1@huawei.com>
Link: https://lore.kernel.org/r/20240124142857.4146716-3-libaokun1@huawei.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-01-25 17:23:51 +01:00
Linus Torvalds
16df6e07d6 vfs-6.8.netfs
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Merge tag 'vfs-6.8.netfs' of gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs

Pull netfs updates from Christian Brauner:
 "This extends the netfs helper library that network filesystems can use
  to replace their own implementations. Both afs and 9p are ported. cifs
  is ready as well but the patches are way bigger and will be routed
  separately once this is merged. That will remove lots of code as well.

  The overal goal is to get high-level I/O and knowledge of the page
  cache and ouf of the filesystem drivers. This includes knowledge about
  the existence of pages and folios

  The pull request converts afs and 9p. This removes about 800 lines of
  code from afs and 300 from 9p. For 9p it is now possible to do writes
  in larger than a page chunks. Additionally, multipage folio support
  can be turned on for 9p. Separate patches exist for cifs removing
  another 2000+ lines. I've included detailed information in the
  individual pulls I took.

  Summary:

   - Add NFS-style (and Ceph-style) locking around DIO vs buffered I/O
     calls to prevent these from happening at the same time.

   - Support for direct and unbuffered I/O.

   - Support for write-through caching in the page cache.

   - O_*SYNC and RWF_*SYNC writes use write-through rather than writing
     to the page cache and then flushing afterwards.

   - Support for write-streaming.

   - Support for write grouping.

   - Skip reads for which the server could only return zeros or EOF.

   - The fscache module is now part of the netfs library and the
     corresponding maintainer entry is updated.

   - Some helpers from the fscache subsystem are renamed to mark them as
     belonging to the netfs library.

   - Follow-up fixes for the netfs library.

   - Follow-up fixes for the 9p conversion"

* tag 'vfs-6.8.netfs' of gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs: (50 commits)
  netfs: Fix wrong #ifdef hiding wait
  cachefiles: Fix signed/unsigned mixup
  netfs: Fix the loop that unmarks folios after writing to the cache
  netfs: Fix interaction between write-streaming and cachefiles culling
  netfs: Count DIO writes
  netfs: Mark netfs_unbuffered_write_iter_locked() static
  netfs: Fix proc/fs/fscache symlink to point to "netfs" not "../netfs"
  netfs: Rearrange netfs_io_subrequest to put request pointer first
  9p: Use length of data written to the server in preference to error
  9p: Do a couple of cleanups
  9p: Fix initialisation of netfs_inode for 9p
  cachefiles: Fix __cachefiles_prepare_write()
  9p: Use netfslib read/write_iter
  afs: Use the netfs write helpers
  netfs: Export the netfs_sreq tracepoint
  netfs: Optimise away reads above the point at which there can be no data
  netfs: Implement a write-through caching option
  netfs: Provide a launder_folio implementation
  netfs: Provide a writepages implementation
  netfs, cachefiles: Pass upper bound length to allow expansion
  ...
2024-01-19 09:10:23 -08:00
Linus Torvalds
78273df7f6 header cleanups for 6.8
The goal is to get sched.h down to a type only header, so the main thing
 happening in this patchset is splitting out various _types.h headers and
 dependency fixups, as well as moving some things out of sched.h to
 better locations.
 
 This is prep work for the memory allocation profiling patchset which
 adds new sched.h interdepencencies.
 
 Testing - it's been in -next, and fixes from pretty much all
 architectures have percolated in - nothing major.
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Merge tag 'header_cleanup-2024-01-10' of https://evilpiepirate.org/git/bcachefs

Pull header cleanups from Kent Overstreet:
 "The goal is to get sched.h down to a type only header, so the main
  thing happening in this patchset is splitting out various _types.h
  headers and dependency fixups, as well as moving some things out of
  sched.h to better locations.

  This is prep work for the memory allocation profiling patchset which
  adds new sched.h interdepencencies"

* tag 'header_cleanup-2024-01-10' of https://evilpiepirate.org/git/bcachefs: (51 commits)
  Kill sched.h dependency on rcupdate.h
  kill unnecessary thread_info.h include
  Kill unnecessary kernel.h include
  preempt.h: Kill dependency on list.h
  rseq: Split out rseq.h from sched.h
  LoongArch: signal.c: add header file to fix build error
  restart_block: Trim includes
  lockdep: move held_lock to lockdep_types.h
  sem: Split out sem_types.h
  uidgid: Split out uidgid_types.h
  seccomp: Split out seccomp_types.h
  refcount: Split out refcount_types.h
  uapi/linux/resource.h: fix include
  x86/signal: kill dependency on time.h
  syscall_user_dispatch.h: split out *_types.h
  mm_types_task.h: Trim dependencies
  Split out irqflags_types.h
  ipc: Kill bogus dependency on spinlock.h
  shm: Slim down dependencies
  workqueue: Split out workqueue_types.h
  ...
2024-01-10 16:43:55 -08:00
David Hildenbrand
4d8f7418e8 mm/rmap: remove page_remove_rmap()
All callers are gone, let's remove it and some leftover traces.

Link: https://lkml.kernel.org/r/20231220224504.646757-33-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Yin Fengwei <fengwei.yin@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-29 11:58:55 -08:00
David Howells
153a9961b5 netfs: Implement unbuffered/DIO write support
Implement support for unbuffered writes and direct I/O writes.  If the
write is misaligned with respect to the fscrypt block size, then RMW cycles
are performed if necessary.  DIO writes are a special case of unbuffered
writes with extra restriction imposed, such as block size alignment
requirements.

Also provide a field that can tell the code to add some extra space onto
the bounce buffer for use by the filesystem in the case of a
content-encrypted file.

Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
2023-12-28 09:45:24 +00:00
David Howells
016dc8516a netfs: Implement unbuffered/DIO read support
Implement support for unbuffered and DIO reads in the netfs library,
utilising the existing read helper code to do block splitting and
individual queuing.  The code also handles extraction of the destination
buffer from the supplied iterator, allowing async unbuffered reads to take
place.

The read will be split up according to the rsize setting and, if supplied,
the ->clamp_length() method.  Note that the next subrequest will be issued
as soon as issue_op returns, without waiting for previous ones to finish.
The network filesystem needs to pause or handle queuing them if it doesn't
want to fire them all at the server simultaneously.

Once all the subrequests have finished, the state will be assessed and the
amount of data to be indicated as having being obtained will be
determined.  As the subrequests may finish in any order, if an intermediate
subrequest is short, any further subrequests may be copied into the buffer
and then abandoned.

In the future, this will also take care of doing an unbuffered read from
encrypted content, with the decryption being done by the library.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
2023-12-28 09:45:23 +00:00
Kent Overstreet
1e2f2d3199 Kill sched.h dependency on rcupdate.h
by moving cond_resched_rcu() to rcupdate_wait.h, we can kill another big
sched.h dependency.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-12-27 11:50:20 -05:00
Andrew Morton
a721aeac8b sync mm-stable with mm-hotfixes-stable to pick up depended-upon changes 2023-12-20 14:47:18 -08:00
Baokun Li
e2c27b803b mm/filemap: avoid buffered read/write race to read inconsistent data
The following concurrency may cause the data read to be inconsistent with
the data on disk:

             cpu1                           cpu2
------------------------------|------------------------------
                               // Buffered write 2048 from 0
                               ext4_buffered_write_iter
                                generic_perform_write
                                 copy_page_from_iter_atomic
                                 ext4_da_write_end
                                  ext4_da_do_write_end
                                   block_write_end
                                    __block_commit_write
                                     folio_mark_uptodate
// Buffered read 4096 from 0          smp_wmb()
ext4_file_read_iter                   set_bit(PG_uptodate, folio_flags)
 generic_file_read_iter            i_size_write // 2048
  filemap_read                     unlock_page(page)
   filemap_get_pages
    filemap_get_read_batch
    folio_test_uptodate(folio)
     ret = test_bit(PG_uptodate, folio_flags)
     if (ret)
      smp_rmb();
      // Ensure that the data in page 0-2048 is up-to-date.

                               // New buffered write 2048 from 2048
                               ext4_buffered_write_iter
                                generic_perform_write
                                 copy_page_from_iter_atomic
                                 ext4_da_write_end
                                  ext4_da_do_write_end
                                   block_write_end
                                    __block_commit_write
                                     folio_mark_uptodate
                                      smp_wmb()
                                      set_bit(PG_uptodate, folio_flags)
                                   i_size_write // 4096
                                   unlock_page(page)

   isize = i_size_read(inode) // 4096
   // Read the latest isize 4096, but without smp_rmb(), there may be
   // Load-Load disorder resulting in the data in the 2048-4096 range
   // in the page is not up-to-date.
   copy_page_to_iter
   // copyout 4096

In the concurrency above, we read the updated i_size, but there is no read
barrier to ensure that the data in the page is the same as the i_size at
this point, so we may copy the unsynchronized page out.  Hence adding the
missing read memory barrier to fix this.

This is a Load-Load reordering issue, which only occurs on some weak
mem-ordering architectures (e.g.  ARM64, ALPHA), but not on strong
mem-ordering architectures (e.g.  X86).  And theoretically the problem
doesn't only happen on ext4, filesystems that call filemap_read() but
don't hold inode lock (e.g.  btrfs, f2fs, ubifs ...) will have this
problem, while filesystems with inode lock (e.g.  xfs, nfs) won't have
this problem.

Link: https://lkml.kernel.org/r/20231213062324.739009-1-libaokun1@huawei.com
Signed-off-by: Baokun Li <libaokun1@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: yangerkun <yangerkun@huawei.com>
Cc: Yu Kuai <yukuai3@huawei.com>
Cc: Zhang Yi <yi.zhang@huawei.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-20 13:46:19 -08:00
Li zeming
a1748f85be mm: filemap: remove unnecessary iitialization of ret
The ret variable can be defined without assigning a value, as it is
assigned before use.

Link: https://lkml.kernel.org/r/20231205022954.101045-1-zeming@nfschina.com
Signed-off-by: Li zeming <zeming@nfschina.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-12 10:57:07 -08:00
Minjie Du
8ff252663d mm/filemap: increase usage of folio_next_index() helper
Simplify code pattern of 'folio->index + folio_nr_pages(folio)' by using
the existing helper folio_next_index() in filemap_get_folios_contig().

Link: https://lkml.kernel.org/r/20231107024635.4512-1-duminjie@vivo.com
Signed-off-by: Minjie Du <duminjie@vivo.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-10 16:51:35 -08:00
Hugh Dickins
9aa1345d66 mm: fix oops when filemap_map_pmd() without prealloc_pte
syzbot reports oops in lockdep's __lock_acquire(), called from
__pte_offset_map_lock() called from filemap_map_pages(); or when I run the
repro, the oops comes in pmd_install(), called from filemap_map_pmd()
called from filemap_map_pages(), just before the __pte_offset_map_lock().

The problem is that filemap_map_pmd() has been assuming that when it finds
pmd_none(), a page table has already been prepared in prealloc_pte; and
indeed do_fault_around() has been careful to preallocate one there, when
it finds pmd_none(): but what if *pmd became none in between?

My 6.6 mods in mm/khugepaged.c, avoiding mmap_lock for write, have made it
easy for *pmd to be cleared while servicing a page fault; but even before
those, a huge *pmd might be zapped while a fault is serviced.

The difference in symptomatic stack traces comes from the "memory model"
in use: pmd_install() uses pmd_populate() uses page_to_pfn(): in some
models that is strict, and will oops on the NULL prealloc_pte; in other
models, it will construct a bogus value to be populated into *pmd, then
__pte_offset_map_lock() oops when trying to access split ptlock pointer
(or some other symptom in normal case of ptlock embedded not pointer).

Link: https://lore.kernel.org/linux-mm/20231115065506.19780-1-jose.pekkarinen@foxhound.fi/
Link: https://lkml.kernel.org/r/6ed0c50c-78ef-0719-b3c5-60c0c010431c@google.com
Fixes: f9ce0be71d ("mm: Cleanup faultaround and finish_fault() codepaths")
Signed-off-by: Hugh Dickins <hughd@google.com>
Reported-and-tested-by: syzbot+89edd67979b52675ddec@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/linux-mm/0000000000005e44550608a0806c@google.com/
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Jann Horn <jannh@google.com>,
Cc: José Pekkarinen <jose.pekkarinen@foxhound.fi>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: <stable@vger.kernel.org>    [5.12+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-06 16:12:45 -08:00
Ryan Roberts
afccb0804f mm: more ptep_get() conversion
Commit c33c794828 ("mm: ptep_get() conversion") converted all (non-arch)
call sites to use ptep_get() instead of doing a direct dereference of the
pte.  Full rationale can be found in that commit's log.

Since then, three new call sites have snuck in, which directly dereference
the pte, so let's fix those up.

Unfortunately there is no reliable automated mechanism to catch these; I'm
relying on a combination of Coccinelle (which throws up a lot of false
positives) and some compiler magic to force a compiler error on
dereference (While this approach finds dereferences, it also yields a
non-booting kernel so can't be committed).

Link: https://lkml.kernel.org/r/20231114154945.490401-1-ryan.roberts@arm.com
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-11-15 15:30:09 -08:00
Lorenzo Stoakes
e8e17ee90e mm: drop the assumption that VM_SHARED always implies writable
Patch series "permit write-sealed memfd read-only shared mappings", v4.

The man page for fcntl() describing memfd file seals states the following
about F_SEAL_WRITE:-

    Furthermore, trying to create new shared, writable memory-mappings via
    mmap(2) will also fail with EPERM.

With emphasis on 'writable'.  In turns out in fact that currently the
kernel simply disallows all new shared memory mappings for a memfd with
F_SEAL_WRITE applied, rendering this documentation inaccurate.

This matters because users are therefore unable to obtain a shared mapping
to a memfd after write sealing altogether, which limits their usefulness. 
This was reported in the discussion thread [1] originating from a bug
report [2].

This is a product of both using the struct address_space->i_mmap_writable
atomic counter to determine whether writing may be permitted, and the
kernel adjusting this counter when any VM_SHARED mapping is performed and
more generally implicitly assuming VM_SHARED implies writable.

It seems sensible that we should only update this mapping if VM_MAYWRITE
is specified, i.e.  whether it is possible that this mapping could at any
point be written to.

If we do so then all we need to do to permit write seals to function as
documented is to clear VM_MAYWRITE when mapping read-only.  It turns out
this functionality already exists for F_SEAL_FUTURE_WRITE - we can
therefore simply adapt this logic to do the same for F_SEAL_WRITE.

We then hit a chicken and egg situation in mmap_region() where the check
for VM_MAYWRITE occurs before we are able to clear this flag.  To work
around this, perform this check after we invoke call_mmap(), with careful
consideration of error paths.

Thanks to Andy Lutomirski for the suggestion!

[1]:https://lore.kernel.org/all/20230324133646.16101dfa666f253c4715d965@linux-foundation.org/
[2]:https://bugzilla.kernel.org/show_bug.cgi?id=217238


This patch (of 3):

There is a general assumption that VMAs with the VM_SHARED flag set are
writable.  If the VM_MAYWRITE flag is not set, then this is simply not the
case.

Update those checks which affect the struct address_space->i_mmap_writable
field to explicitly test for this by introducing
[vma_]is_shared_maywrite() helper functions.

This remains entirely conservative, as the lack of VM_MAYWRITE guarantees
that the VMA cannot be written to.

Link: https://lkml.kernel.org/r/cover.1697116581.git.lstoakes@gmail.com
Link: https://lkml.kernel.org/r/d978aefefa83ec42d18dfa964ad180dbcde34795.1697116581.git.lstoakes@gmail.com
Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com>
Suggested-by: Andy Lutomirski <luto@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-18 14:34:19 -07:00
Matthew Wilcox (Oracle)
b0b598ee08 filemap: remove use of wait bookmarks
The original problem of the overly long list of waiters on a locked page
was solved properly by commit 9a1ea439b1 ("mm:
put_and_wait_on_page_locked() while page is migrated").  In the meantime,
using bookmarks for the writeback bit can cause livelocks, so we need to
stop using them.

Link: https://lkml.kernel.org/r/20231010035829.544242-1-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Bin Lai <sclaibin@gmail.com>
Cc: Benjamin Segall <bsegall@google.com>
Cc: Daniel Bristot de Oliveira <bristot@redhat.com>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: Valentin Schneider <vschneid@redhat.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>

Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-18 14:34:18 -07:00
Nhat Pham
85ce2c517a memcontrol: only transfer the memcg data for migration
For most migration use cases, only transfer the memcg data from the old
folio to the new folio, and clear the old folio's memcg data.  No charging
and uncharging will be done.

This shaves off some work on the migration path, and avoids the temporary
double charging of a folio during its migration.

The only exception is replace_page_cache_folio(), which will use the old
mem_cgroup_migrate() (now renamed to mem_cgroup_replace_folio).  In that
context, the isolation of the old page isn't quite as thorough as with
migration, so we cannot use our new implementation directly.

This patch is the result of the following discussion on the new hugetlb
memcg accounting behavior:

https://lore.kernel.org/lkml/20231003171329.GB314430@monkey/

Link: https://lkml.kernel.org/r/20231006184629.155543-3-nphamcs@gmail.com
Signed-off-by: Nhat Pham <nphamcs@gmail.com>
Suggested-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Frank van der Linden <fvdl@google.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Rik van Riel <riel@surriel.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Tejun heo <tj@kernel.org>
Cc: Yosry Ahmed <yosryahmed@google.com>
Cc: Zefan Li <lizefan.x@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-18 14:34:17 -07:00
Matthew Wilcox (Oracle)
2580d55458 mm: use folio_xor_flags_has_waiters() in folio_end_writeback()
Match how folio_unlock() works by combining the test for PG_waiters with
the clearing of PG_writeback.  This should have a small performance win,
and removes the last user of folio_wake().

Link: https://lkml.kernel.org/r/20231004165317.1061855-18-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Richard Henderson <richard.henderson@linaro.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-18 14:34:17 -07:00
Matthew Wilcox (Oracle)
7d0795d098 mm: make __end_folio_writeback() return void
Rather than check the result of test-and-clear, just check that we have
the writeback bit set at the start.  This wouldn't catch every case, but
it's good enough (and enables the next patch).

Link: https://lkml.kernel.org/r/20231004165317.1061855-17-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Richard Henderson <richard.henderson@linaro.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-18 14:34:17 -07:00
Matthew Wilcox (Oracle)
0410cd844e mm: add folio_xor_flags_has_waiters()
Optimise folio_end_read() by setting the uptodate bit at the same time we
clear the unlock bit.  This saves at least one memory barrier and one
write-after-write hazard.

Link: https://lkml.kernel.org/r/20231004165317.1061855-16-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Richard Henderson <richard.henderson@linaro.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-18 14:34:17 -07:00
Matthew Wilcox (Oracle)
f12fb73b74 mm: delete checks for xor_unlock_is_negative_byte()
Architectures which don't define their own use the one in
asm-generic/bitops/lock.h.  Get rid of all the ifdefs around "maybe we
don't have it".

Link: https://lkml.kernel.org/r/20231004165317.1061855-15-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Richard Henderson <richard.henderson@linaro.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-18 14:34:17 -07:00
Matthew Wilcox (Oracle)
247dbcdbf7 bitops: add xor_unlock_is_negative_byte()
Replace clear_bit_and_unlock_is_negative_byte() with
xor_unlock_is_negative_byte().  We have a few places that like to lock a
folio, set a flag and unlock it again.  Allow for the possibility of
combining the latter two operations for efficiency.  We are guaranteed
that the caller holds the lock, so it is safe to unlock it with the xor. 
The caller must guarantee that nobody else will set the flag without
holding the lock; it is not safe to do this with the PG_dirty flag, for
example.

Link: https://lkml.kernel.org/r/20231004165317.1061855-8-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Richard Henderson <richard.henderson@linaro.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-18 14:34:16 -07:00
Matthew Wilcox (Oracle)
0b237047d5 mm: add folio_end_read()
Provide a function for filesystems to call when they have finished reading
an entire folio.

Link: https://lkml.kernel.org/r/20231004165317.1061855-4-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Richard Henderson <richard.henderson@linaro.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-18 14:34:16 -07:00
Pankaj Raghav
bafd7e9d35 filemap: call filemap_get_folios_tag() from filemap_get_folios()
filemap_get_folios() is filemap_get_folios_tag() with XA_PRESENT as the
tag that is being matched.  Return filemap_get_folios_tag() with
XA_PRESENT as the tag instead of duplicating the code in
filemap_get_folios().

No functional changes.

Link: https://lkml.kernel.org/r/20231006110120.136809-1-kernel@pankajraghav.com
Signed-off-by: Pankaj Raghav <p.raghav@samsung.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-18 14:34:16 -07:00
Matthew Wilcox (Oracle)
5d74b2ab2c mm: make lock_folio_maybe_drop_mmap() VMA lock aware
Patch series "Handle more faults under the VMA lock", v2.

At this point, we're handling the majority of file-backed page faults
under the VMA lock, using the ->map_pages entry point.  This patch set
attempts to expand that for the following siutations:

 - We have to do a read.  This could be because we've hit the point in
   the readahead window where we need to kick off the next readahead,
   or because the page is simply not present in cache.
 - We're handling a write fault.  Most applications don't do I/O by writes
   to shared mmaps for very good reasons, but some do, and it'd be nice
   to not make that slow unnecessarily.
 - We're doing a COW of a private mapping (both PTE already present
   and PTE not-present).  These are two different codepaths and I handle
   both of them in this patch set.

There is no support in this patch set for drivers to mark themselves as
being VMA lock friendly; they could implement the ->map_pages
vm_operation, but if they do, they would be the first.  This is probably
something we want to change at some point in the future, and I've marked
where to make that change in the code.

There is very little performance change in the benchmarks we've run;
mostly because the vast majority of page faults are handled through the
other paths.  I still think this patch series is useful for workloads that
may take these paths more often, and just for cleaning up the fault path
in general (it's now clearer why we have to retry in these cases).


This patch (of 6):

Drop the VMA lock instead of the mmap_lock if that's the one which
is held.

Link: https://lkml.kernel.org/r/20231006195318.4087158-1-willy@infradead.org
Link: https://lkml.kernel.org/r/20231006195318.4087158-2-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-18 14:34:14 -07:00