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mm/vmscan: convert shrink_active_list() to use a folio

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Remove a few hidden calls to compound_head, saving 411 bytes of text.

Link: https://lkml.kernel.org/r/20220617154248.700416-5-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Matthew Wilcox (Oracle) 2022-06-17 16:42:47 +01:00 committed by akpm
parent ff00a170d9
commit 07f67a8ded
1 changed files with 29 additions and 32 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

61
mm/vmscan.c
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@ -26,8 +26,7 @@
#include <linux/file.h> #include <linux/file.h>
#include <linux/writeback.h> #include <linux/writeback.h>
#include <linux/blkdev.h> #include <linux/blkdev.h>
#include <linux/buffer_head.h> /* for try_to_release_page(), #include <linux/buffer_head.h> /* for buffer_heads_over_limit */
buffer_heads_over_limit */
#include <linux/mm_inline.h> #include <linux/mm_inline.h>
#include <linux/backing-dev.h> #include <linux/backing-dev.h>
#include <linux/rmap.h> #include <linux/rmap.h>
@ -2483,21 +2482,21 @@ shrink_inactive_list(unsigned long nr_to_scan, struct lruvec *lruvec,
} }
/* /*
* shrink_active_list() moves pages from the active LRU to the inactive LRU. * shrink_active_list() moves folios from the active LRU to the inactive LRU.
* *
* We move them the other way if the page is referenced by one or more * We move them the other way if the folio is referenced by one or more
* processes. * processes.
* *
* If the pages are mostly unmapped, the processing is fast and it is * If the folios are mostly unmapped, the processing is fast and it is
* appropriate to hold lru_lock across the whole operation. But if * appropriate to hold lru_lock across the whole operation. But if
* the pages are mapped, the processing is slow (folio_referenced()), so * the folios are mapped, the processing is slow (folio_referenced()), so
* we should drop lru_lock around each page. It's impossible to balance * we should drop lru_lock around each folio. It's impossible to balance
* this, so instead we remove the pages from the LRU while processing them. * this, so instead we remove the folios from the LRU while processing them.
* It is safe to rely on PG_active against the non-LRU pages in here because * It is safe to rely on the active flag against the non-LRU folios in here
* nobody will play with that bit on a non-LRU page. * because nobody will play with that bit on a non-LRU folio.
* *
* The downside is that we have to touch page->_refcount against each page. * The downside is that we have to touch folio->_refcount against each folio.
* But we had to alter page->flags anyway. * But we had to alter folio->flags anyway.
*/ */
static void shrink_active_list(unsigned long nr_to_scan, static void shrink_active_list(unsigned long nr_to_scan,
struct lruvec *lruvec, struct lruvec *lruvec,
@ -2507,7 +2506,7 @@ static void shrink_active_list(unsigned long nr_to_scan,
unsigned long nr_taken; unsigned long nr_taken;
unsigned long nr_scanned; unsigned long nr_scanned;
unsigned long vm_flags; unsigned long vm_flags;
LIST_HEAD(l_hold); /* The pages which were snipped off */ LIST_HEAD(l_hold); /* The folios which were snipped off */
LIST_HEAD(l_active); LIST_HEAD(l_active);
LIST_HEAD(l_inactive); LIST_HEAD(l_inactive);
unsigned nr_deactivate, nr_activate; unsigned nr_deactivate, nr_activate;
@ -2532,23 +2531,21 @@ static void shrink_active_list(unsigned long nr_to_scan,
while (!list_empty(&l_hold)) { while (!list_empty(&l_hold)) {
struct folio *folio; struct folio *folio;
struct page *page;
cond_resched(); cond_resched();
folio = lru_to_folio(&l_hold); folio = lru_to_folio(&l_hold);
list_del(&folio->lru); list_del(&folio->lru);
page = &folio->page;
if (unlikely(!page_evictable(page))) { if (unlikely(!folio_evictable(folio))) {
putback_lru_page(page); folio_putback_lru(folio);
continue; continue;
} }
if (unlikely(buffer_heads_over_limit)) { if (unlikely(buffer_heads_over_limit)) {
if (page_has_private(page) && trylock_page(page)) { if (folio_get_private(folio) && folio_trylock(folio)) {
if (page_has_private(page)) if (folio_get_private(folio))
try_to_release_page(page, 0); filemap_release_folio(folio, 0);
unlock_page(page); folio_unlock(folio);
} }
} }
@ -2556,34 +2553,34 @@ static void shrink_active_list(unsigned long nr_to_scan,
if (folio_referenced(folio, 0, sc->target_mem_cgroup, if (folio_referenced(folio, 0, sc->target_mem_cgroup,
&vm_flags) != 0) { &vm_flags) != 0) {
/* /*
* Identify referenced, file-backed active pages and * Identify referenced, file-backed active folios and
* give them one more trip around the active list. So * give them one more trip around the active list. So
* that executable code get better chances to stay in * that executable code get better chances to stay in
* memory under moderate memory pressure. Anon pages * memory under moderate memory pressure. Anon folios
* are not likely to be evicted by use-once streaming * are not likely to be evicted by use-once streaming
* IO, plus JVM can create lots of anon VM_EXEC pages, * IO, plus JVM can create lots of anon VM_EXEC folios,
* so we ignore them here. * so we ignore them here.
*/ */
if ((vm_flags & VM_EXEC) && page_is_file_lru(page)) { if ((vm_flags & VM_EXEC) && folio_is_file_lru(folio)) {
nr_rotated += thp_nr_pages(page); nr_rotated += folio_nr_pages(folio);
list_add(&page->lru, &l_active); list_add(&folio->lru, &l_active);
continue; continue;
} }
} }
ClearPageActive(page); /* we are de-activating */ folio_clear_active(folio); /* we are de-activating */
SetPageWorkingset(page); folio_set_workingset(folio);
list_add(&page->lru, &l_inactive); list_add(&folio->lru, &l_inactive);
} }
/* /*
* Move pages back to the lru list. * Move folios back to the lru list.
*/ */
spin_lock_irq(&lruvec->lru_lock); spin_lock_irq(&lruvec->lru_lock);
nr_activate = move_pages_to_lru(lruvec, &l_active); nr_activate = move_pages_to_lru(lruvec, &l_active);
nr_deactivate = move_pages_to_lru(lruvec, &l_inactive); nr_deactivate = move_pages_to_lru(lruvec, &l_inactive);
/* Keep all free pages in l_active list */ /* Keep all free folios in l_active list */
list_splice(&l_inactive, &l_active); list_splice(&l_inactive, &l_active);
__count_vm_events(PGDEACTIVATE, nr_deactivate); __count_vm_events(PGDEACTIVATE, nr_deactivate);