Messages in this thread | | | Date | Thu, 31 Jul 2014 11:06:53 -0400 | From | Johannes Weiner <> | Subject | Re: [PATCH 2/2] memcg, vmscan: Fix forced scan of anonymous pages |
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On Thu, Jul 31, 2014 at 01:49:45PM +0200, Jerome Marchand wrote: > When memory cgoups are enabled, the code that decides to force to scan > anonymous pages in get_scan_count() compares global values (free, > high_watermark) to a value that is restricted to a memory cgroup > (file). It make the code over-eager to force anon scan. > > For instance, it will force anon scan when scanning a memcg that is > mainly populated by anonymous page, even when there is plenty of file > pages to get rid of in others memcgs, even when swappiness == 0. It > breaks user's expectation about swappiness and hurts performance. > > This patch make sure that forced anon scan only happens when there not > enough file pages for the all zone, not just in one random memcg. > > Signed-off-by: Jerome Marchand <jmarchan@redhat.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
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