linux-kernel - Re: additional oom-killer tuneable worth submitting?

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Date:	Thu, 7 Dec 2006 23:22:07 +0000
From:	Alan <alan@...rguk.ukuu.org.uk>
To:	"Chris Friesen" <cfriesen@...tel.com>
Cc:	linux-kernel@...r.kernel.org
Subject: Re: additional oom-killer tuneable worth submitting?

> We add a new "oom_thresh" member to the task struct.
> We introduce a new proc entry "/proc/<pid>/oomthresh" to control it.
> 
> The "oom-thresh" value maps to the max expected memory consumption for 
> that process.  As long as a process uses less memory than the specified 
> threshold, then it is immune to the oom-killer.

You've just introduced a deadlock. What happens if nobody is over that
predicted memory and the kernel uses more resource ?
> 
> On an embedded platform this allows the designer to engineer the system 
> and protect critical apps based on their expected memory consumption. 
> If one of those apps goes crazy and starts chewing additional memory 
> then it becomes vulnerable to the oom killer while the other apps remain 
> protected.

That is why we have no-overcommit support. Now there is an argument for
a meaningful rlimit-as to go with it, and together I think they do what
you really need.

Alan
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