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Date: Mon, 15 Nov 2010 11:20:19 +0000
Message-ID: <AANLkTi=jo3avY3-cgjsmkCcpKab6VHe6Nz_Xz-_HKYsT@mail.gmail.com>
Subject: Re: [Qemu-devel] Re: [PATCH 2/3] virtio-pci: Use ioeventfd for
	virtqueue notify
From: Stefan Hajnoczi <stefanha@gmail.com>
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To: Avi Kivity <avi@redhat.com>
Cc: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>, kvm@vger.kernel.org, "Michael S. Tsirkin" <mst@redhat.com>, qemu-devel@nongnu.org, Christoph Hellwig <hch@infradead.org>, Khoa Huynh <khoa@us.ibm.com>

On Sun, Nov 14, 2010 at 12:19 PM, Avi Kivity <avi@redhat.com> wrote:
> On 11/14/2010 01:05 PM, Avi Kivity wrote:
>>>
>>> I agree, but let's enable virtio-ioeventfd carefully because bad code
>>> is out there.
>>
>>
>> Sure. =A0Note as long as the thread waiting on ioeventfd doesn't consume=
 too
>> much cpu, it will awaken quickly and we won't have the "transaction per
>> timeslice" effect.
>>
>> btw, what about virtio-blk with linux-aio? =A0Have you benchmarked that =
with
>> and without ioeventfd?
>>
>
> And, what about efficiency? =A0As in bits/cycle?

We are running benchmarks with this latest patch and will report results.

Stefan