Commit 1489fa14 authored by Mel Gorman's avatar Mel Gorman Committed by Linus Torvalds
Browse files

vmscan: update isolated page counters outside of main path in shrink_inactive_list() 



When shrink_inactive_list() isolates pages, it updates a number of
counters using temporary variables to gather them.  These consume stack
and it's in the main path that calls ->writepage().  This patch moves the
accounting updates outside of the main path to reduce stack usage.

Signed-off-by: default avatarMel Gorman <mel@csn.ul.ie>
Reviewed-by: default avatarJohannes Weiner <hannes@cmpxchg.org>
Acked-by: default avatarRik van Riel <riel@redhat.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Michael Rubin <mrubin@google.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent abe4c3b5

mm/vmscan.c

+38 −25
Original line number Diff line number Diff line
@@ -1076,6 +1076,7 @@ static unsigned long clear_active_flags(struct list_head *page_list, 
			ClearPageActive(page);

			nr_active++;

		}

		if (count)

			count[lru]++;

	}
@@ -1156,12 +1157,13 @@ static int too_many_isolated(struct zone *zone, int file, 
 * TODO: Try merging with migrations version of putback_lru_pages

 */

static noinline_for_stack void

putback_lru_pages(struct zone *zone, struct zone_reclaim_stat *reclaim_stat,

putback_lru_pages(struct zone *zone, struct scan_control *sc,

				unsigned long nr_anon, unsigned long nr_file,

				struct list_head *page_list)

{

	struct page *page;

	struct pagevec pvec;

	struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(zone, sc);



	pagevec_init(&pvec, 1);
@@ -1200,6 +1202,37 @@ putback_lru_pages(struct zone *zone, struct zone_reclaim_stat *reclaim_stat, 
	pagevec_release(&pvec);

}



static noinline_for_stack void update_isolated_counts(struct zone *zone,

					struct scan_control *sc,

					unsigned long *nr_anon,

					unsigned long *nr_file,

					struct list_head *isolated_list)

{

	unsigned long nr_active;

	unsigned int count[NR_LRU_LISTS] = { 0, };

	struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(zone, sc);



	nr_active = clear_active_flags(isolated_list, count);

	__count_vm_events(PGDEACTIVATE, nr_active);



	__mod_zone_page_state(zone, NR_ACTIVE_FILE,

			      -count[LRU_ACTIVE_FILE]);

	__mod_zone_page_state(zone, NR_INACTIVE_FILE,

			      -count[LRU_INACTIVE_FILE]);

	__mod_zone_page_state(zone, NR_ACTIVE_ANON,

			      -count[LRU_ACTIVE_ANON]);

	__mod_zone_page_state(zone, NR_INACTIVE_ANON,

			      -count[LRU_INACTIVE_ANON]);



	*nr_anon = count[LRU_ACTIVE_ANON] + count[LRU_INACTIVE_ANON];

	*nr_file = count[LRU_ACTIVE_FILE] + count[LRU_INACTIVE_FILE];

	__mod_zone_page_state(zone, NR_ISOLATED_ANON, *nr_anon);

	__mod_zone_page_state(zone, NR_ISOLATED_FILE, *nr_file);



	reclaim_stat->recent_scanned[0] += *nr_anon;

	reclaim_stat->recent_scanned[1] += *nr_file;

}



/*

 * shrink_inactive_list() is a helper for shrink_zone().  It returns the number

 * of reclaimed pages
@@ -1211,10 +1244,8 @@ shrink_inactive_list(unsigned long nr_to_scan, struct zone *zone, 
	LIST_HEAD(page_list);

	unsigned long nr_scanned;

	unsigned long nr_reclaimed = 0;

	struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(zone, sc);

	unsigned long nr_taken;

	unsigned long nr_active;

	unsigned int count[NR_LRU_LISTS] = { 0, };

	unsigned long nr_anon;

	unsigned long nr_file;
@@ -1261,25 +1292,7 @@ shrink_inactive_list(unsigned long nr_to_scan, struct zone *zone, 
		return 0;

	}



	nr_active = clear_active_flags(&page_list, count);

	__count_vm_events(PGDEACTIVATE, nr_active);



	__mod_zone_page_state(zone, NR_ACTIVE_FILE,

					-count[LRU_ACTIVE_FILE]);

	__mod_zone_page_state(zone, NR_INACTIVE_FILE,

					-count[LRU_INACTIVE_FILE]);

	__mod_zone_page_state(zone, NR_ACTIVE_ANON,

					-count[LRU_ACTIVE_ANON]);

	__mod_zone_page_state(zone, NR_INACTIVE_ANON,

					-count[LRU_INACTIVE_ANON]);



	nr_anon = count[LRU_ACTIVE_ANON] + count[LRU_INACTIVE_ANON];

	nr_file = count[LRU_ACTIVE_FILE] + count[LRU_INACTIVE_FILE];

	__mod_zone_page_state(zone, NR_ISOLATED_ANON, nr_anon);

	__mod_zone_page_state(zone, NR_ISOLATED_FILE, nr_file);



	reclaim_stat->recent_scanned[0] += nr_anon;

	reclaim_stat->recent_scanned[1] += nr_file;

	update_isolated_counts(zone, sc, &nr_anon, &nr_file, &page_list);



	spin_unlock_irq(&zone->lru_lock);
@@ -1299,7 +1312,7 @@ shrink_inactive_list(unsigned long nr_to_scan, struct zone *zone, 
		 * The attempt at page out may have made some

		 * of the pages active, mark them inactive again.

		 */

		nr_active = clear_active_flags(&page_list, count);

		nr_active = clear_active_flags(&page_list, NULL);

		count_vm_events(PGDEACTIVATE, nr_active);



		nr_reclaimed += shrink_page_list(&page_list, sc, PAGEOUT_IO_SYNC);
@@ -1310,7 +1323,7 @@ shrink_inactive_list(unsigned long nr_to_scan, struct zone *zone, 
		__count_vm_events(KSWAPD_STEAL, nr_reclaimed);

	__count_zone_vm_events(PGSTEAL, zone, nr_reclaimed);



	putback_lru_pages(zone, reclaim_stat, nr_anon, nr_file, &page_list);

	putback_lru_pages(zone, sc, nr_anon, nr_file, &page_list);

	return nr_reclaimed;

}

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