Re: [Qemu-devel] [PATCH] posix-aio-compat: fix latency issues

[Avi Kivity]

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