Re: [Qemu-devel] [PATCH] Use qemu_eventfd for POSIX AIO

[Avi Kivity]

On 09/27/2011 05:29 PM, Jan Kiszka wrote:
> >
> >  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().
>
> I don't get this yet. eventfd is lossy by default. It only decreases the
> counter on read if you specify EFD_SEMAPHORE - which we do not do.

It's not lossy - a read returns the number of events written since the 
last read.

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error compiling committee.c: too many arguments to function