Commit 9f6c399d authored Jan 14, 2016 by Michal Hocko Committed by Linus Torvalds Jan 14, 2016

mm, vmscan: consider isolated pages in zone_reclaimable_pages



zone_reclaimable_pages counts how many pages are reclaimable in the
given zone.  This currently includes all pages on file lrus and anon
lrus if there is an available swap storage.  We do not consider
NR_ISOLATED_{ANON,FILE} counters though which is not correct because
these counters reflect temporarily isolated pages which are still
reclaimable because they either get back to their LRU or get freed
either by the page reclaim or page migration.

The number of these pages might be sufficiently high to confuse users of
zone_reclaimable_pages (e.g.  mbind can migrate large ranges of memory
at once).

Signed-off-by: Michal Hocko <mhocko@suse.com>
Suggested-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent b832861c

mm/vmscan.c

+4 −2

Original line number	Diff line number	Diff line
		@@ -197,11 +197,13 @@ static unsigned long zone_reclaimable_pages(struct zone *zone)
		unsigned long nr;

		nr = zone_page_state(zone, NR_ACTIVE_FILE) +
		zone_page_state(zone, NR_INACTIVE_FILE);
		zone_page_state(zone, NR_INACTIVE_FILE) +
		zone_page_state(zone, NR_ISOLATED_FILE);

		if (get_nr_swap_pages() > 0)
		nr += zone_page_state(zone, NR_ACTIVE_ANON) +
		zone_page_state(zone, NR_INACTIVE_ANON);
		zone_page_state(zone, NR_INACTIVE_ANON) +
		zone_page_state(zone, NR_ISOLATED_ANON);

		return nr;
		}

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