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Date: Tue, 27 Sep 2011 17:11:40 +0300
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Subject: Re: [Qemu-devel] [PATCH] Use qemu_eventfd for POSIX AIO
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To: Anthony Liguori <anthony@codemonkey.ws>
Cc: Kevin Wolf <kwolf@redhat.com>, Anthony Liguori <aliguori@us.ibm.com>, Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>, Jan Kiszka <jan.kiszka@siemens.com>, Marcelo Tosatti <mtosatti@redhat.com>, qemu-devel <qemu-devel@nongnu.org>

On 09/27/2011 05:07 PM, Anthony Liguori wrote:
>
> You don't expect to handle EAGAIN with eventfd() whereas you have to 
> handle it with pipe().
>
> Moreover, the eventfd() counter is not lossy (practically speaking) 
> whereas if you use pipe() as a counter, it will be lossy in practice.
>
> This is why posix aio uses pipe() and not eventfd().

We could define a qemu_event mechanism that satisfies the least common 
denominator, and is implemented by eventfd when available.

qemu_event_create()
qemu_event_signal()
qemu_event_wait()
qemu_event_poll_add() // registers in main loop
qemu_event_poll_del()

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