mirrors/linux
1
0
Fork 1
mirror of https://github.com/torvalds/linux.git synced 2025-11-04 02:30:34 +02:00
Code Issues Projects Releases Packages Wiki Activity Actions

mm: code cleanup for MADV_FREE

Browse source 
Some comments for MADV_FREE is revised and added to help people understand
the MADV_FREE code, especially the page flag, PG_swapbacked.  This makes
page_is_file_cache() isn't consistent with its comments.  So the function
is renamed to page_is_file_lru() to make them consistent again.  All these
are put in one patch as one logical change.

Suggested-by: David Hildenbrand <david@redhat.com>
Suggested-by: Johannes Weiner <hannes@cmpxchg.org>
Suggested-by: David Rientjes <rientjes@google.com>
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Michal Hocko <mhocko@kernel.org>
Acked-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Rik van Riel <riel@surriel.com>
Link: http://lkml.kernel.org/r/20200317100342.2730705-1-ying.huang@intel.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Huang Ying 2020-04-06 20:04:41 -07:00 committed by Linus Torvalds
parent 7a9547fd4e
commit 9de4f22a60
13 changed files with 44 additions and 38 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

15
include/linux/mm_inline.h
View file

@ -6,19 +6,20 @@
#include <linux/swap.h> #include <linux/swap.h>
/** /**
* page_is_file_cache - should the page be on a file LRU or anon LRU? * page_is_file_lru - should the page be on a file LRU or anon LRU?
* @page: the page to test * @page: the page to test
* *
* Returns 1 if @page is page cache page backed by a regular filesystem, * Returns 1 if @page is a regular filesystem backed page cache page or a lazily
* or 0 if @page is anonymous, tmpfs or otherwise ram or swap backed. * freed anonymous page (e.g. via MADV_FREE). Returns 0 if @page is a normal
* Used by functions that manipulate the LRU lists, to sort a page * anonymous page, a tmpfs page or otherwise ram or swap backed page. Used by
* onto the right LRU list. * functions that manipulate the LRU lists, to sort a page onto the right LRU
* list.
* *
* We would like to get this info without a page flag, but the state * We would like to get this info without a page flag, but the state
* needs to survive until the page is last deleted from the LRU, which * needs to survive until the page is last deleted from the LRU, which
* could be as far down as __page_cache_release. * could be as far down as __page_cache_release.
*/ */
static inline int page_is_file_cache(struct page *page) static inline int page_is_file_lru(struct page *page)
{ {
return !PageSwapBacked(page); return !PageSwapBacked(page);
} }
@ -75,7 +76,7 @@ static __always_inline void del_page_from_lru_list(struct page *page,
*/ */
static inline enum lru_list page_lru_base_type(struct page *page) static inline enum lru_list page_lru_base_type(struct page *page)
{ {
if (page_is_file_cache(page)) if (page_is_file_lru(page))
return LRU_INACTIVE_FILE; return LRU_INACTIVE_FILE;
return LRU_INACTIVE_ANON; return LRU_INACTIVE_ANON;
} }

5
include/linux/page-flags.h
View file

@ -63,6 +63,11 @@
* page_waitqueue(page) is a wait queue of all tasks waiting for the page * page_waitqueue(page) is a wait queue of all tasks waiting for the page
* to become unlocked. * to become unlocked.
* *
* PG_swapbacked is set when a page uses swap as a backing storage. This are
* usually PageAnon or shmem pages but please note that even anonymous pages
* might lose their PG_swapbacked flag when they simply can be dropped (e.g. as
* a result of MADV_FREE).
*
* PG_uptodate tells whether the page's contents is valid. When a read * PG_uptodate tells whether the page's contents is valid. When a read
* completes, the page becomes uptodate, unless a disk I/O error happened. * completes, the page becomes uptodate, unless a disk I/O error happened.
* *

2
include/trace/events/vmscan.h
View file

@ -323,7 +323,7 @@ TRACE_EVENT(mm_vmscan_writepage,
TP_fast_assign( TP_fast_assign(
__entry->pfn = page_to_pfn(page); __entry->pfn = page_to_pfn(page);
__entry->reclaim_flags = trace_reclaim_flags( __entry->reclaim_flags = trace_reclaim_flags(
page_is_file_cache(page)); page_is_file_lru(page));
), ),
TP_printk("page=%p pfn=%lu flags=%s", TP_printk("page=%p pfn=%lu flags=%s",

2
mm/compaction.c
View file

@ -989,7 +989,7 @@ isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn,
/* Successfully isolated */ /* Successfully isolated */
del_page_from_lru_list(page, lruvec, page_lru(page)); del_page_from_lru_list(page, lruvec, page_lru(page));
mod_node_page_state(page_pgdat(page), mod_node_page_state(page_pgdat(page),
NR_ISOLATED_ANON + page_is_file_cache(page), NR_ISOLATED_ANON + page_is_file_lru(page),
hpage_nr_pages(page)); hpage_nr_pages(page));
isolate_success: isolate_success:

2
mm/gup.c
View file

@ -1677,7 +1677,7 @@ static long check_and_migrate_cma_pages(struct task_struct *tsk,
list_add_tail(&head->lru, &cma_page_list); list_add_tail(&head->lru, &cma_page_list);
mod_node_page_state(page_pgdat(head), mod_node_page_state(page_pgdat(head),
NR_ISOLATED_ANON + NR_ISOLATED_ANON +
page_is_file_cache(head), page_is_file_lru(head),
hpage_nr_pages(head)); hpage_nr_pages(head));
} }
} }

4
mm/khugepaged.c
View file

@ -511,7 +511,7 @@ void __khugepaged_exit(struct mm_struct *mm)
static void release_pte_page(struct page *page) static void release_pte_page(struct page *page)
{ {
dec_node_page_state(page, NR_ISOLATED_ANON + page_is_file_cache(page)); dec_node_page_state(page, NR_ISOLATED_ANON + page_is_file_lru(page));
unlock_page(page); unlock_page(page);
putback_lru_page(page); putback_lru_page(page);
} }
@ -611,7 +611,7 @@ static int __collapse_huge_page_isolate(struct vm_area_struct *vma,
goto out; goto out;
} }
inc_node_page_state(page, inc_node_page_state(page,
NR_ISOLATED_ANON + page_is_file_cache(page)); NR_ISOLATED_ANON + page_is_file_lru(page));
VM_BUG_ON_PAGE(!PageLocked(page), page); VM_BUG_ON_PAGE(!PageLocked(page), page);
VM_BUG_ON_PAGE(PageLRU(page), page); VM_BUG_ON_PAGE(PageLRU(page), page);

2
mm/memory-failure.c
View file

@ -1810,7 +1810,7 @@ static int __soft_offline_page(struct page *page, int flags)
*/ */
if (!__PageMovable(page)) if (!__PageMovable(page))
inc_node_page_state(page, NR_ISOLATED_ANON + inc_node_page_state(page, NR_ISOLATED_ANON +
page_is_file_cache(page)); page_is_file_lru(page));
list_add(&page->lru, &pagelist); list_add(&page->lru, &pagelist);
ret = migrate_pages(&pagelist, new_page, NULL, MPOL_MF_MOVE_ALL, ret = migrate_pages(&pagelist, new_page, NULL, MPOL_MF_MOVE_ALL,
MIGRATE_SYNC, MR_MEMORY_FAILURE); MIGRATE_SYNC, MR_MEMORY_FAILURE);

2
mm/memory_hotplug.c
View file

@ -1317,7 +1317,7 @@ do_migrate_range(unsigned long start_pfn, unsigned long end_pfn)
list_add_tail(&page->lru, &source); list_add_tail(&page->lru, &source);
if (!__PageMovable(page)) if (!__PageMovable(page))
inc_node_page_state(page, NR_ISOLATED_ANON + inc_node_page_state(page, NR_ISOLATED_ANON +
page_is_file_cache(page)); page_is_file_lru(page));
} else { } else {
pr_warn("failed to isolate pfn %lx\n", pfn); pr_warn("failed to isolate pfn %lx\n", pfn);

2
mm/mempolicy.c
View file

@ -1022,7 +1022,7 @@ static int migrate_page_add(struct page *page, struct list_head *pagelist,
if (!isolate_lru_page(head)) { if (!isolate_lru_page(head)) {
list_add_tail(&head->lru, pagelist); list_add_tail(&head->lru, pagelist);
mod_node_page_state(page_pgdat(head), mod_node_page_state(page_pgdat(head),
NR_ISOLATED_ANON + page_is_file_cache(head), NR_ISOLATED_ANON + page_is_file_lru(head),
hpage_nr_pages(head)); hpage_nr_pages(head));
} else if (flags & MPOL_MF_STRICT) { } else if (flags & MPOL_MF_STRICT) {
/* /*

16
mm/migrate.c
View file

@ -193,7 +193,7 @@ void putback_movable_pages(struct list_head *l)
put_page(page); put_page(page);
} else { } else {
mod_node_page_state(page_pgdat(page), NR_ISOLATED_ANON + mod_node_page_state(page_pgdat(page), NR_ISOLATED_ANON +
page_is_file_cache(page), -hpage_nr_pages(page)); page_is_file_lru(page), -hpage_nr_pages(page));
putback_lru_page(page); putback_lru_page(page);
} }
} }
@ -1219,7 +1219,7 @@ static ICE_noinline int unmap_and_move(new_page_t get_new_page,
*/ */
if (likely(!__PageMovable(page))) if (likely(!__PageMovable(page)))
mod_node_page_state(page_pgdat(page), NR_ISOLATED_ANON + mod_node_page_state(page_pgdat(page), NR_ISOLATED_ANON +
page_is_file_cache(page), -hpage_nr_pages(page)); page_is_file_lru(page), -hpage_nr_pages(page));
} }
/* /*
@ -1592,7 +1592,7 @@ static int add_page_for_migration(struct mm_struct *mm, unsigned long addr,
err = 1; err = 1;
list_add_tail(&head->lru, pagelist); list_add_tail(&head->lru, pagelist);
mod_node_page_state(page_pgdat(head), mod_node_page_state(page_pgdat(head),
NR_ISOLATED_ANON + page_is_file_cache(head), NR_ISOLATED_ANON + page_is_file_lru(head),
hpage_nr_pages(head)); hpage_nr_pages(head));
} }
out_putpage: out_putpage:
@ -1955,7 +1955,7 @@ static int numamigrate_isolate_page(pg_data_t *pgdat, struct page *page)
return 0; return 0;
} }
page_lru = page_is_file_cache(page); page_lru = page_is_file_lru(page);
mod_node_page_state(page_pgdat(page), NR_ISOLATED_ANON + page_lru, mod_node_page_state(page_pgdat(page), NR_ISOLATED_ANON + page_lru,
hpage_nr_pages(page)); hpage_nr_pages(page));
@ -1991,7 +1991,7 @@ int migrate_misplaced_page(struct page *page, struct vm_area_struct *vma,
* Don't migrate file pages that are mapped in multiple processes * Don't migrate file pages that are mapped in multiple processes
* with execute permissions as they are probably shared libraries. * with execute permissions as they are probably shared libraries.
*/ */
if (page_mapcount(page) != 1 && page_is_file_cache(page) && if (page_mapcount(page) != 1 && page_is_file_lru(page) &&
(vma->vm_flags & VM_EXEC)) (vma->vm_flags & VM_EXEC))
goto out; goto out;
@ -1999,7 +1999,7 @@ int migrate_misplaced_page(struct page *page, struct vm_area_struct *vma,
* Also do not migrate dirty pages as not all filesystems can move * Also do not migrate dirty pages as not all filesystems can move
* dirty pages in MIGRATE_ASYNC mode which is a waste of cycles. * dirty pages in MIGRATE_ASYNC mode which is a waste of cycles.
*/ */
if (page_is_file_cache(page) && PageDirty(page)) if (page_is_file_lru(page) && PageDirty(page))
goto out; goto out;
isolated = numamigrate_isolate_page(pgdat, page); isolated = numamigrate_isolate_page(pgdat, page);
@ -2014,7 +2014,7 @@ int migrate_misplaced_page(struct page *page, struct vm_area_struct *vma,
if (!list_empty(&migratepages)) { if (!list_empty(&migratepages)) {
list_del(&page->lru); list_del(&page->lru);
dec_node_page_state(page, NR_ISOLATED_ANON + dec_node_page_state(page, NR_ISOLATED_ANON +
page_is_file_cache(page)); page_is_file_lru(page));
putback_lru_page(page); putback_lru_page(page);
} }
isolated = 0; isolated = 0;
@ -2044,7 +2044,7 @@ int migrate_misplaced_transhuge_page(struct mm_struct *mm,
pg_data_t *pgdat = NODE_DATA(node); pg_data_t *pgdat = NODE_DATA(node);
int isolated = 0; int isolated = 0;
struct page *new_page = NULL; struct page *new_page = NULL;
int page_lru = page_is_file_cache(page); int page_lru = page_is_file_lru(page);
unsigned long start = address & HPAGE_PMD_MASK; unsigned long start = address & HPAGE_PMD_MASK;
new_page = alloc_pages_node(node, new_page = alloc_pages_node(node,

2
mm/mprotect.c
View file

@ -98,7 +98,7 @@ static unsigned long change_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
* it cannot move them all from MIGRATE_ASYNC * it cannot move them all from MIGRATE_ASYNC
* context. * context.
*/ */
if (page_is_file_cache(page) && PageDirty(page)) if (page_is_file_lru(page) && PageDirty(page))
continue; continue;
/* /*

16
mm/swap.c
View file

@ -276,7 +276,7 @@ static void __activate_page(struct page *page, struct lruvec *lruvec,
void *arg) void *arg)
{ {
if (PageLRU(page) && !PageActive(page) && !PageUnevictable(page)) { if (PageLRU(page) && !PageActive(page) && !PageUnevictable(page)) {
int file = page_is_file_cache(page); int file = page_is_file_lru(page);
int lru = page_lru_base_type(page); int lru = page_lru_base_type(page);
del_page_from_lru_list(page, lruvec, lru); del_page_from_lru_list(page, lruvec, lru);
@ -394,7 +394,7 @@ void mark_page_accessed(struct page *page)
else else
__lru_cache_activate_page(page); __lru_cache_activate_page(page);
ClearPageReferenced(page); ClearPageReferenced(page);
if (page_is_file_cache(page)) if (page_is_file_lru(page))
workingset_activation(page); workingset_activation(page);
} }
if (page_is_idle(page)) if (page_is_idle(page))
@ -515,7 +515,7 @@ static void lru_deactivate_file_fn(struct page *page, struct lruvec *lruvec,
return; return;
active = PageActive(page); active = PageActive(page);
file = page_is_file_cache(page); file = page_is_file_lru(page);
lru = page_lru_base_type(page); lru = page_lru_base_type(page);
del_page_from_lru_list(page, lruvec, lru + active); del_page_from_lru_list(page, lruvec, lru + active);
@ -548,7 +548,7 @@ static void lru_deactivate_fn(struct page *page, struct lruvec *lruvec,
void *arg) void *arg)
{ {
if (PageLRU(page) && PageActive(page) && !PageUnevictable(page)) { if (PageLRU(page) && PageActive(page) && !PageUnevictable(page)) {
int file = page_is_file_cache(page); int file = page_is_file_lru(page);
int lru = page_lru_base_type(page); int lru = page_lru_base_type(page);
del_page_from_lru_list(page, lruvec, lru + LRU_ACTIVE); del_page_from_lru_list(page, lruvec, lru + LRU_ACTIVE);
@ -573,9 +573,9 @@ static void lru_lazyfree_fn(struct page *page, struct lruvec *lruvec,
ClearPageActive(page); ClearPageActive(page);
ClearPageReferenced(page); ClearPageReferenced(page);
/* /*
* lazyfree pages are clean anonymous pages. They have * Lazyfree pages are clean anonymous pages. They have
* SwapBacked flag cleared to distinguish normal anonymous * PG_swapbacked flag cleared, to distinguish them from normal
* pages * anonymous pages
*/ */
ClearPageSwapBacked(page); ClearPageSwapBacked(page);
add_page_to_lru_list(page, lruvec, LRU_INACTIVE_FILE); add_page_to_lru_list(page, lruvec, LRU_INACTIVE_FILE);
@ -962,7 +962,7 @@ static void __pagevec_lru_add_fn(struct page *page, struct lruvec *lruvec,
if (page_evictable(page)) { if (page_evictable(page)) {
lru = page_lru(page); lru = page_lru(page);
update_page_reclaim_stat(lruvec, page_is_file_cache(page), update_page_reclaim_stat(lruvec, page_is_file_lru(page),
PageActive(page)); PageActive(page));
if (was_unevictable) if (was_unevictable)
count_vm_event(UNEVICTABLE_PGRESCUED); count_vm_event(UNEVICTABLE_PGRESCUED);

12
mm/vmscan.c
View file

@ -919,7 +919,7 @@ static int __remove_mapping(struct address_space *mapping, struct page *page,
* exceptional entries and shadow exceptional entries in the * exceptional entries and shadow exceptional entries in the
* same address_space. * same address_space.
*/ */
if (reclaimed && page_is_file_cache(page) && if (reclaimed && page_is_file_lru(page) &&
!mapping_exiting(mapping) && !dax_mapping(mapping)) !mapping_exiting(mapping) && !dax_mapping(mapping))
shadow = workingset_eviction(page, target_memcg); shadow = workingset_eviction(page, target_memcg);
__delete_from_page_cache(page, shadow); __delete_from_page_cache(page, shadow);
@ -1043,7 +1043,7 @@ static void page_check_dirty_writeback(struct page *page,
* Anonymous pages are not handled by flushers and must be written * Anonymous pages are not handled by flushers and must be written
* from reclaim context. Do not stall reclaim based on them * from reclaim context. Do not stall reclaim based on them
*/ */
if (!page_is_file_cache(page) || if (!page_is_file_lru(page) ||
(PageAnon(page) && !PageSwapBacked(page))) { (PageAnon(page) && !PageSwapBacked(page))) {
*dirty = false; *dirty = false;
*writeback = false; *writeback = false;
@ -1315,7 +1315,7 @@ static unsigned long shrink_page_list(struct list_head *page_list,
* the rest of the LRU for clean pages and see * the rest of the LRU for clean pages and see
* the same dirty pages again (PageReclaim). * the same dirty pages again (PageReclaim).
*/ */
if (page_is_file_cache(page) && if (page_is_file_lru(page) &&
(!current_is_kswapd() || !PageReclaim(page) || (!current_is_kswapd() || !PageReclaim(page) ||
!test_bit(PGDAT_DIRTY, &pgdat->flags))) { !test_bit(PGDAT_DIRTY, &pgdat->flags))) {
/* /*
@ -1459,7 +1459,7 @@ static unsigned long shrink_page_list(struct list_head *page_list,
try_to_free_swap(page); try_to_free_swap(page);
VM_BUG_ON_PAGE(PageActive(page), page); VM_BUG_ON_PAGE(PageActive(page), page);
if (!PageMlocked(page)) { if (!PageMlocked(page)) {
int type = page_is_file_cache(page); int type = page_is_file_lru(page);
SetPageActive(page); SetPageActive(page);
stat->nr_activate[type] += nr_pages; stat->nr_activate[type] += nr_pages;
count_memcg_page_event(page, PGACTIVATE); count_memcg_page_event(page, PGACTIVATE);
@ -1497,7 +1497,7 @@ unsigned long reclaim_clean_pages_from_list(struct zone *zone,
LIST_HEAD(clean_pages); LIST_HEAD(clean_pages);
list_for_each_entry_safe(page, next, page_list, lru) { list_for_each_entry_safe(page, next, page_list, lru) {
if (page_is_file_cache(page) && !PageDirty(page) && if (page_is_file_lru(page) && !PageDirty(page) &&
!__PageMovable(page) && !PageUnevictable(page)) { !__PageMovable(page) && !PageUnevictable(page)) {
ClearPageActive(page); ClearPageActive(page);
list_move(&page->lru, &clean_pages); list_move(&page->lru, &clean_pages);
@ -2053,7 +2053,7 @@ static void shrink_active_list(unsigned long nr_to_scan,
* IO, plus JVM can create lots of anon VM_EXEC pages, * IO, plus JVM can create lots of anon VM_EXEC pages,
* so we ignore them here. * so we ignore them here.
*/ */
if ((vm_flags & VM_EXEC) && page_is_file_cache(page)) { if ((vm_flags & VM_EXEC) && page_is_file_lru(page)) {
list_add(&page->lru, &l_active); list_add(&page->lru, &l_active);
continue; continue;
} }