mm: count only reclaimable lru pages
authorWu Fengguang <fengguang.wu@intel.com>
Tue, 22 Sep 2009 00:01:42 +0000 (17:01 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Tue, 22 Sep 2009 14:17:30 +0000 (07:17 -0700)
commitadea02a1bea71a508da32c04d715485a1fe62029
treec78742bbab36bf3b8d20f84b4dc6dc6585bb7cb4
parent55c37a840d9ec0ebed5c944355156d490b1ad5d1
mm: count only reclaimable lru pages

global_lru_pages() / zone_lru_pages() can be used in two ways:
- to estimate max reclaimable pages in determine_dirtyable_memory()
- to calculate the slab scan ratio

When swap is full or not present, the anon lru lists are not reclaimable
and also won't be scanned.  So the anon pages shall not be counted in both
usage scenarios.  Also rename to _reclaimable_pages: now they are counting
the possibly reclaimable lru pages.

It can greatly (and correctly) increase the slab scan rate under high
memory pressure (when most file pages have been reclaimed and swap is
full/absent), thus reduce false OOM kills.

Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Reviewed-by: Rik van Riel <riel@redhat.com>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Cc: David Howells <dhowells@redhat.com>
Cc: "Li, Ming Chun" <macli@brc.ubc.ca>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
include/linux/vmstat.h
mm/page-writeback.c
mm/vmscan.c