From: Avi Kivity <avi@redhat.com>
To: Anthony Liguori <aliguori@linux.vnet.ibm.com>
Cc: Steve Dobbelstein <steved@us.ibm.com>,
Anthony Liguori <aliguori@us.ibm.com>,
Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>,
kvm@vger.kernel.org, "Michael S. Tsirkin" <mst@redhat.com>,
qemu-devel@nongnu.org, Khoa Huynh <khoa@us.ibm.com>,
sri@linux.vnet.ibm.com
Subject: Re: [Qemu-devel] Re: [PATCH] virtio: Use ioeventfd for virtqueue notify
Date: Mon, 04 Oct 2010 10:04:29 +0200 [thread overview]
Message-ID: <4CA98A8D.4000500@redhat.com> (raw)
In-Reply-To: <4CA92B79.2030805@linux.vnet.ibm.com>
On 10/04/2010 03:18 AM, Anthony Liguori wrote:
> On 10/03/2010 09:28 AM, Michael S. Tsirkin wrote:
>>
>>> This is using eventfd as well.
>> Sorry, I meant irqfd.
>
> I've tried using irqfd in userspace. It hurts performance quite a bit
> compared to doing an ioctl so I would suspect this too.
>
> A last_used_idx or similar mechanism should help performance quite a
> bit on top of ioeventfd too.
>
Any idea why? While irqfd does quite a bit of extra locking, it
shouldn't be that bad.
--
I have a truly marvellous patch that fixes the bug which this
signature is too narrow to contain.
next prev parent reply other threads:[~2010-10-04 8:04 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-09-30 14:01 [Qemu-devel] [PATCH] virtio: Use ioeventfd for virtqueue notify Stefan Hajnoczi
2010-10-03 11:01 ` [Qemu-devel] " Avi Kivity
2010-10-03 13:51 ` Michael S. Tsirkin
2010-10-03 14:21 ` Avi Kivity
2010-10-03 14:28 ` Michael S. Tsirkin
2010-10-04 1:18 ` Anthony Liguori
2010-10-04 8:04 ` Avi Kivity [this message]
2010-10-04 14:01 ` Anthony Liguori
2010-10-04 16:12 ` Michael S. Tsirkin
2010-10-04 16:20 ` Anthony Liguori
2010-10-04 16:25 ` Michael S. Tsirkin
2010-10-04 14:30 ` Stefan Hajnoczi
2010-10-05 11:00 ` rukhsana ansari
2010-10-05 11:58 ` Avi Kivity
2010-10-19 13:07 ` Stefan Hajnoczi
2010-10-19 13:12 ` Anthony Liguori
2010-10-19 13:35 ` Michael S. Tsirkin
2010-10-19 13:44 ` Stefan Hajnoczi
2010-10-19 13:43 ` Michael S. Tsirkin
2010-11-10 14:52 ` Stefan Hajnoczi
2010-10-19 13:33 ` Michael S. Tsirkin
2010-10-25 13:25 ` Stefan Hajnoczi
2010-10-25 15:01 ` Stefan Hajnoczi
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