Re: [RFC][-mm][PATCH 5/6] oom-killer: check last total_vm expansion

From: KAMEZAWA Hiroyuki
Date: Tue Nov 03 2009 - 19:28:18 EST


On Tue, 3 Nov 2009 12:29:39 -0800 (PST)
David Rientjes <rientjes@xxxxxxxxxx> wrote:

> On Mon, 2 Nov 2009, KAMEZAWA Hiroyuki wrote:
>
> > From: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
> >
> > At considering oom-kill algorithm, we can't avoid to take runtime
> > into account. But this can adds too big bonus to slow-memory-leaker.
> > For adding penalty to slow-memory-leaker, we record jiffies of
> > the last mm->hiwater_vm expansion. That catches processes which leak
> > memory periodically.
> >
>
> No, it doesn't, it simply measures the last time the hiwater mark was
> increased. That could have increased by a single page in the last tick
> with no increase in memory consumption over the past year and then its
> unfairly biased against for quiet_time in the new oom kill heuristic
> (patch 6). Using this as part of the badness scoring is ill conceived
> because it doesn't necessarily indicate a memory leaking task, just one
> that has recently allocated memory.

Hmm. Maybe I can rewrite this as "periodic expansion have done or not" code.
Okay, this patch itself will be dropped.

If you find better algorithm, let me know.

Thanks,
-Kame

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