Re: [Xen-devel] [PATCH] Dump flush write performance

To:	Ben Guthro <bguthro@xxxxxxxxxxxxxxx>, xen-devel <xen-devel@xxxxxxxxxxxxxxxxxxx>
Subject:	Re: [Xen-devel] [PATCH] Dump flush write performance
From:	Keir Fraser <Keir.Fraser@xxxxxxxxxxxx>
Date:	Thu, 25 Oct 2007 15:32:59 +0100
Cc:	Daniel Li <dli@xxxxxxxxxxxxxxx>
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On 24/10/07 22:10, "Ben Guthro" <bguthro@xxxxxxxxxxxxxxx> wrote:

> Two changes to avoid disk driver using up kernel memory and triggering
> oom-killer
> while creating guest dump to a disk file:
> 
> 1) Decreased write chunks from 16MB to 2MB;
> 2) Flush (fsync) after each 2MB write.

I don't think we've had any reports of core dumping causing oom killer to
kick in. It seems a bit unlikely after all, unless you're really running
dom0 close to the wire. A user process write()ing a big file shouldn't be
able to trigger oom killer imo.

 -- Keir

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Re: [Xen-devel] [PATCH] Dump flush write performance