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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
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61
mm/vmscan.c
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@ -26,8 +26,7 @@
#include <linux/file.h>
#include <linux/writeback.h>
#include <linux/blkdev.h>
#include <linux/buffer_head.h> /* for try_to_release_page(),
buffer_heads_over_limit */
#include <linux/buffer_head.h> /* for buffer_heads_over_limit */
#include <linux/mm_inline.h>
#include <linux/backing-dev.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.
*
* 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
* the pages are mapped, the processing is slow (folio_referenced()), so
* we should drop lru_lock around each page. It's impossible to balance
* this, so instead we remove the pages from the LRU while processing them.
* It is safe to rely on PG_active against the non-LRU pages in here because
* nobody will play with that bit on a non-LRU page.
* the folios are mapped, the processing is slow (folio_referenced()), so
* we should drop lru_lock around each folio. It's impossible to balance
* this, so instead we remove the folios from the LRU while processing them.
* It is safe to rely on the active flag against the non-LRU folios in here
* 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.
* But we had to alter page->flags anyway.
* The downside is that we have to touch folio->_refcount against each folio.
* But we had to alter folio->flags anyway.
*/
static void shrink_active_list(unsigned long nr_to_scan,
struct lruvec *lruvec,
@ -2507,7 +2506,7 @@ static void shrink_active_list(unsigned long nr_to_scan,
unsigned long nr_taken;
unsigned long nr_scanned;
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_inactive);
unsigned nr_deactivate, nr_activate;
@ -2532,23 +2531,21 @@ static void shrink_active_list(unsigned long nr_to_scan,
while (!list_empty(&l_hold)) {
struct folio *folio;
struct page *page;
cond_resched();
folio = lru_to_folio(&l_hold);
list_del(&folio->lru);
page = &folio->page;
if (unlikely(!page_evictable(page))) {
putback_lru_page(page);
if (unlikely(!folio_evictable(folio))) {
folio_putback_lru(folio);
continue;
}
if (unlikely(buffer_heads_over_limit)) {
if (page_has_private(page) && trylock_page(page)) {
if (page_has_private(page))
try_to_release_page(page, 0);
unlock_page(page);
if (folio_get_private(folio) && folio_trylock(folio)) {
if (folio_get_private(folio))
filemap_release_folio(folio, 0);
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,
&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
* 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
* 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.
*/
if ((vm_flags & VM_EXEC) && page_is_file_lru(page)) {
nr_rotated += thp_nr_pages(page);
list_add(&page->lru, &l_active);
if ((vm_flags & VM_EXEC) && folio_is_file_lru(folio)) {
nr_rotated += folio_nr_pages(folio);
list_add(&folio->lru, &l_active);
continue;
}
}
ClearPageActive(page); /* we are de-activating */
SetPageWorkingset(page);
list_add(&page->lru, &l_inactive);
folio_clear_active(folio); /* we are de-activating */
folio_set_workingset(folio);
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);
nr_activate = move_pages_to_lru(lruvec, &l_active);
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);
__count_vm_events(PGDEACTIVATE, nr_deactivate);