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From: Avi Kivity <avi@redhat.com>
To: Frediano Ziglio <freddy77@gmail.com>
Cc: qemu-devel@nongnu.org, kvm@vger.kernel.org
Subject: Re: [Qemu-devel] [PATCH] posix-aio-compat: fix latency issues
Date: Mon, 08 Aug 2011 16:26:25 +0300	[thread overview]
Message-ID: <4E3FE401.6080701@redhat.com> (raw)
In-Reply-To: <CAHt6W4eyfPHKNUzmPkmKd+xEMobEJXaM7jKZDJMLD-4UOpnNfA@mail.gmail.com>

On 08/08/2011 04:21 PM, Frediano Ziglio wrote:
> >
> >  The entire qemu process may be affined to a subset of the host cpus; we
> >  don't want to break that.
> >
> >  For example:
> >
> >     taskset 0xf0 qemu ....
> >     (qemu) info cpus
> >  <pin individual vcpu threads to host cpus>
> >
> >
>
> Just call sched_getaffinity at program start, save to a global
> variable and then set this affinity for io threads.

This affinity may change later on.

> I didn't use affinity that much but from manual it seems that if you
> own process you can set affinity as you like.
> IMHO this patch introduce a delay in io thread creation due to posting
> thread creation to another thread just to set different affinity.

It does.  But aio threads have a long life, so this happens very rarely.

-- 
error compiling committee.c: too many arguments to function

  reply	other threads:[~2011-08-08 13:26 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-08-08 11:37 [Qemu-devel] [PATCH] posix-aio-compat: fix latency issues Avi Kivity
2011-08-08 12:34 ` Anthony Liguori
2011-08-08 12:42   ` Avi Kivity
2011-08-08 12:49 ` Frediano Ziglio
2011-08-08 12:54   ` Avi Kivity
2011-08-08 13:21     ` Frediano Ziglio
2011-08-08 13:26       ` Avi Kivity [this message]
2011-08-12 13:24 ` Anthony Liguori
2011-08-14  3:43   ` Avi Kivity

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