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

Remove a few hidden calls to compound_head, saving 279 bytes of text.

Link: https://lkml.kernel.org/r/20220617154248.700416-3-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 16:42:45 +01:00 committed by akpm
parent b8cecb9376
commit 166e3d3227
1 changed files with 33 additions and 33 deletions
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66
mm/vmscan.c
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@ -160,17 +160,17 @@ struct scan_control {
};
#ifdef ARCH_HAS_PREFETCHW
#define prefetchw_prev_lru_page(_page, _base, _field) \
#define prefetchw_prev_lru_folio(_folio, _base, _field) \
do { \
if ((_page)->lru.prev != _base) { \
struct page *prev; \
if ((_folio)->lru.prev != _base) { \
struct folio *prev; \
\
prev = lru_to_page(&(_page->lru)); \
prev = lru_to_folio(&(_folio->lru)); \
prefetchw(&prev->_field); \
} \
} while (0)
#else
#define prefetchw_prev_lru_page(_page, _base, _field) do { } while (0)
#define prefetchw_prev_lru_folio(_folio, _base, _field) do { } while (0)
#endif
/*
@ -2139,72 +2139,72 @@ static unsigned long isolate_lru_pages(unsigned long nr_to_scan,
unsigned long nr_skipped[MAX_NR_ZONES] = { 0, };
unsigned long skipped = 0;
unsigned long scan, total_scan, nr_pages;
LIST_HEAD(pages_skipped);
LIST_HEAD(folios_skipped);
total_scan = 0;
scan = 0;
while (scan < nr_to_scan && !list_empty(src)) {
struct list_head *move_to = src;
struct page *page;
struct folio *folio;
page = lru_to_page(src);
prefetchw_prev_lru_page(page, src, flags);
folio = lru_to_folio(src);
prefetchw_prev_lru_folio(folio, src, flags);
nr_pages = compound_nr(page);
nr_pages = folio_nr_pages(folio);
total_scan += nr_pages;
if (page_zonenum(page) > sc->reclaim_idx) {
nr_skipped[page_zonenum(page)] += nr_pages;
move_to = &pages_skipped;
if (folio_zonenum(folio) > sc->reclaim_idx) {
nr_skipped[folio_zonenum(folio)] += nr_pages;
move_to = &folios_skipped;
goto move;
}
/*
* Do not count skipped pages because that makes the function
* return with no isolated pages if the LRU mostly contains
* ineligible pages. This causes the VM to not reclaim any
* pages, triggering a premature OOM.
* Account all tail pages of THP.
* Do not count skipped folios because that makes the function
* return with no isolated folios if the LRU mostly contains
* ineligible folios. This causes the VM to not reclaim any
* folios, triggering a premature OOM.
* Account all pages in a folio.
*/
scan += nr_pages;
if (!PageLRU(page))
if (!folio_test_lru(folio))
goto move;
if (!sc->may_unmap && page_mapped(page))
if (!sc->may_unmap && folio_mapped(folio))
goto move;
/*
* Be careful not to clear PageLRU until after we're
* sure the page is not being freed elsewhere -- the
* page release code relies on it.
* Be careful not to clear the lru flag until after we're
* sure the folio is not being freed elsewhere -- the
* folio release code relies on it.
*/
if (unlikely(!get_page_unless_zero(page)))
if (unlikely(!folio_try_get(folio)))
goto move;
if (!TestClearPageLRU(page)) {
/* Another thread is already isolating this page */
put_page(page);
if (!folio_test_clear_lru(folio)) {
/* Another thread is already isolating this folio */
folio_put(folio);
goto move;
}
nr_taken += nr_pages;
nr_zone_taken[page_zonenum(page)] += nr_pages;
nr_zone_taken[folio_zonenum(folio)] += nr_pages;
move_to = dst;
move:
list_move(&page->lru, move_to);
list_move(&folio->lru, move_to);
}
/*
* Splice any skipped pages to the start of the LRU list. Note that
* Splice any skipped folios to the start of the LRU list. Note that
* this disrupts the LRU order when reclaiming for lower zones but
* we cannot splice to the tail. If we did then the SWAP_CLUSTER_MAX
* scanning would soon rescan the same pages to skip and waste lots
* scanning would soon rescan the same folios to skip and waste lots
* of cpu cycles.
*/
if (!list_empty(&pages_skipped)) {
if (!list_empty(&folios_skipped)) {
int zid;
list_splice(&pages_skipped, src);
list_splice(&folios_skipped, src);
for (zid = 0; zid < MAX_NR_ZONES; zid++) {
if (!nr_skipped[zid])
continue;