Date: Thu, 26 Nov 2015 10:56:12 +0900
From: Joonsoo Kim <iamjoonsoo.kim@lge.com>
To: Michal Hocko <mhocko@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>, linux-kernel@vger.kernel.org,
        Christoph Lameter <cl@linux.com>, linux-mm@kvack.org
Subject: Re: [PATCH] mm/vmstat: retrieve more accurate vmstat value
Message-ID: <20151126015612.GB13138@js1304-P5Q-DELUXE>
References: <1448346123-2699-1-git-send-email-iamjoonsoo.kim@lge.com>
 <20151125120021.GA27342@dhcp22.suse.cz>
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On Wed, Nov 25, 2015 at 01:00:22PM +0100, Michal Hocko wrote:
> On Tue 24-11-15 15:22:03, Joonsoo Kim wrote:
> > When I tested compaction in low memory condition, I found that
> > my benchmark is stuck in congestion_wait() at shrink_inactive_list().
> > This stuck last for 1 sec and after then it can escape. More investigation
> > shows that it is due to stale vmstat value. vmstat is updated every 1 sec
> > so it is stuck for 1 sec.
> 
> Wouldn't it be sufficient to use zone_page_state_snapshot in
> too_many_isolated?

Yes, it would work in this case. But, I prefer this patch because
all zone_page_state() users get this benefit.

Thanks.
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