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Date: Wed, 24 Sep 2008 09:17:07 -0500
From: Anthony Liguori <aliguori@us.ibm.com>
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Subject: [Qemu-devel] Re: [PATCH] Implement an fd pool to get real AIO with
	posix-aio
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To: Avi Kivity <avi@redhat.com>
Cc: Ryan Harper <ryanh@us.ibm.com>, qemu-devel@nongnu.org, kvm <kvm@vger.kernel.org>

Avi Kivity wrote:
> Anthony Liguori wrote:
>
> dup()ing the fd on each request is unnecessary work; would be better 
> to cache the duped fd.

Yeah, I was concerned about this too.  Ryan reran the fio benchmark and 
the submission latency and completion latency were identical to the 
linux-aio patches.  That suggests that the overhead of dup() is lost in 
the noise.

Since this is simpler and keeps the number of open file descriptors as 
low as possible, I was happy about that.

Regards,

Anthony Liguori

> Of course, if this is just a stepping stone, it doesn't matter very much.
>