From: Stefan Hajnoczi <stefanha@redhat.com>
To: Alexandre DERUMIER <aderumier@odiso.com>
Cc: josh durgin <josh.durgin@inktank.com>,
qemu-devel <qemu-devel@nongnu.org>
Subject: Re: [Qemu-devel] is it possible to use a disk with multiple iothreads ?
Date: Mon, 27 Oct 2014 13:19:58 +0000 [thread overview]
Message-ID: <20141027131958.GC15071@stefanha-thinkpad.redhat.com> (raw)
In-Reply-To: <884af3f3-d7fc-4080-8c54-09384314e006@mailpro>
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On Fri, Oct 24, 2014 at 03:39:52PM +0200, Alexandre DERUMIER wrote:
> >>Regarding Ceph, do you know why it burns a lot of CPU?
>
> I'm currently doing some perfs to find why is so huge.
>
> One thing is that qemu+ qemu rbd block driver + librbd seem to use 2-3x more cpu, than passing krbd /dev/rbd0 from host to qemu.
> Don't known yet if the problem is librbd or qemu rbd block driver.
That's very interesting! Please keep Josh and me in CC when you want to
discuss the results.
Stefan
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next prev parent reply other threads:[~2014-10-27 13:20 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <391d6bb1-e0ad-49ea-afdc-fff462081f24@mailpro>
2014-10-23 18:26 ` [Qemu-devel] is it possible to use a disk with multiple iothreads ? Alexandre DERUMIER
2014-10-24 9:04 ` Stefan Hajnoczi
2014-10-24 13:39 ` Alexandre DERUMIER
2014-10-27 13:19 ` Stefan Hajnoczi [this message]
2014-10-27 14:13 ` Alexandre DERUMIER
2014-10-27 14:47 ` Paolo Bonzini
2014-10-27 16:42 ` Alexandre DERUMIER
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