linux-kernel - Re: [why oom_adj does not work] Re: Linux killed Kenny, bastard!

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Message-ID: <20090115223557.GC10429@ioremap.net>
Date:	Fri, 16 Jan 2009 01:35:57 +0300
From:	Evgeniy Polyakov <zbr@...emap.net>
To:	Bodo Eggert <7eggert@....de>
Cc:	Alan Cox <alan@...rguk.ukuu.org.uk>, Dave Jones <davej@...hat.com>,
	linux-kernel@...r.kernel.org,
	Andrew Morton <akpm@...ux-foundation.org>,
	Linus Torvalds <torvalds@...ux-foundation.org>
Subject: Re: [why oom_adj does not work] Re: Linux killed Kenny, bastard!

On Thu, Jan 15, 2009 at 10:50:58PM +0100, Bodo Eggert (7eggert@....de) wrote:
> > This does not work if processes are short-living and are spawned by the
> > parent on demand.
> 
> They will have the same name, too. Your Kenny-killer will fail, too.

It is not always the case, processes start executing different binaries
and change the names, that's at least what I observed in the particular
root case of the discussion.

> > If processes have different priority in regards to oom
> > condition, this problem can not be solved with existing interfaces
> > without changing the application. So effectively there is no solution.
> 
> ACK, but being a child should count. Maybe the weight for childs should be 
> increased, if it does not do the right thing? Or maybe the childs do share 
> much (most of the) memory, so killing the parent is the right thing if you 
> want to free some RAM?

There could be lots of heuristics applied for the different cases, but
without changing the application, they are somewhat limited to
long-living processes only. There are really lots of cases when it does
not stand.

-- 
	Evgeniy Polyakov
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