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Date: Wed, 8 Jul 2015 09:02:32 +0800
From: Fam Zheng <famz@redhat.com>
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Subject: Re: [Qemu-devel] [PATCH RFC 0/4] aio: Use epoll_wait in aio_poll
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To: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Kevin Wolf <kwolf@redhat.com>, pbonzini@redhat.com, Stefan Hajnoczi <stefanha@redhat.com>, qemu-devel@nongnu.org, qemu-block@nongnu.org

On Tue, 07/07 16:54, Christian Borntraeger wrote:
> Am 30.06.2015 um 15:19 schrieb Fam Zheng:
> > epoll is more scalable than ppoll. It performs faster than ppoll when the
> > number of polled fds is high.
> > 
> > See patch 4 for an example of the senario and some benchmark data.
> > 
> > Note: it is only effective on iothread (dataplane), while the main loop cannot
> > benefit from this yet, because the iohandler and chardev GSource's don't easily
> > fit into this epoll interface style (that's why main loop uses qemu_poll_ns
> > directly instead of aio_poll()).
> > 
> > There is hardly any timer activity in iothreads for now, as a result the
> > timeout is always 0 or -1. Therefore, timerfd, or the said nanosecond
> > epoll_pwait1 interface, which fixes the timeout granularity deficiency is not
> > immediately necessary at this point, but still that will be simple to add.
> > 
> > Please review!
> 
> Is there a branch somewhere, so that I could give it a spin?
> 

Here:

https://github.com/famz/qemu/tree/aio-posix-epoll