Re: Found the commit that causes the OOMs

From: KOSAKI Motohiro
Date: Wed Jul 01 2009 - 00:19:01 EST


> On Tue, Jun 30, 2009 at 10:57:02PM -0400, Rik van Riel wrote:
> > KOSAKI Motohiro wrote:
> >
> >>> [ 1522.019259] Active_anon:11 active_file:6 inactive_anon:0
> >>> [ 1522.019260] inactive_file:0 unevictable:0 dirty:0 writeback:0 unstable:0
> >>> [ 1522.019261] free:1985 slab:44399 mapped:132 pagetables:61830 bounce:0
> >>> [ 1522.019262] isolate:69817
> >>
> >> OK. thanks.
> >> I plan to submit this patch after small more tests. it is useful for OOM analysis.
> >
> > It is also useful for throttling page reclaim.
> >
> > If more than half of the inactive pages in a zone are
> > isolated, we are probably beyond the point where adding
> > additional reclaim processes will do more harm than good.
>
> There are probably more problems in this case. For example,
> followed is the vmstat after first (successful) run of msgctl11.
>
> The question is: Why kswapd reclaims are absent here?

if direct reclaim isolate all pages, kswapd can't reclaim any pages.

I believe Rik's idea solve this problem.


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