From: Pekka Enberg <penberg@kernel.org>
To: Ingo Molnar <mingo@elte.hu>
Cc: Anthony Liguori <anthony@codemonkey.ws>,
Asias He <asias.hejun@gmail.com>,
"Michael S. Tsirkin" <mst@redhat.com>,
Rusty Russell <rusty@rustcorp.com.au>,
Mark McLoughlin <markmc@redhat.com>,
Cyrill Gorcunov <gorcunov@gmail.com>,
Sasha Levin <levinsasha928@gmail.com>,
Prasad Joshi <prasadjoshi124@gmail.com>,
kvm@vger.kernel.org
Subject: Re: [PATCH 1/2] kvm tools: Respect ISR status in virtio header
Date: Sat, 07 May 2011 17:52:40 +0300 [thread overview]
Message-ID: <1304779960.10621.16.camel@jaguar> (raw)
In-Reply-To: <20110507144735.GD2859@elte.hu>
On Sat, 2011-05-07 at 16:47 +0200, Ingo Molnar wrote:
> Can you anything in the virtio protocol implementation that would explain
> networking lags, which seem to be caused by guest notifications either not be
> sent or being missed?
>
> In particular this sequence:
>
> > while pending_requests:
> > a = get_next_request();
> > process_next_request(a);
>
> is apparently not what Qemu uses - so maybe there's some latent bug or some
> silly oversight somewhere.
>
> It is suboptimal and i agree with you that the better sequence should be
> implemented, but the above *should* work, yet it does not.
Yes, so the performance benefits of Asias' patch aren't the interesting
part but the fact that it fixes a real bug in our tool.
Pekka
next prev parent reply other threads:[~2011-05-07 14:52 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-05-07 2:34 [PATCH 1/2] kvm tools: Respect ISR status in virtio header Asias He
2011-05-07 2:34 ` [PATCH 2/2] kvm tools: Respect VRING_AVAIL_F_NO_INTERRUPT Asias He
2011-05-07 7:55 ` Ingo Molnar
2011-05-07 9:03 ` Pekka Enberg
2011-05-07 11:25 ` Asias He
2011-05-07 9:30 ` [PATCH 1/2] kvm tools: Respect ISR status in virtio header Ingo Molnar
2011-05-07 10:34 ` Sasha Levin
2011-05-07 10:39 ` Pekka Enberg
2011-05-07 10:39 ` Asias He
2011-05-07 11:15 ` Asias He
2011-05-07 14:00 ` Ingo Molnar
2011-05-07 14:24 ` Asias He
2011-05-07 13:14 ` Anthony Liguori
2011-05-07 14:02 ` Ingo Molnar
2011-05-07 14:21 ` Anthony Liguori
2011-05-07 14:47 ` Ingo Molnar
2011-05-07 14:52 ` Pekka Enberg [this message]
2011-05-07 14:55 ` Ingo Molnar
2011-05-07 14:50 ` Pekka Enberg
2011-05-07 15:01 ` Anthony Liguori
2011-05-07 15:02 ` Pekka Enberg
2011-05-07 15:06 ` Ingo Molnar
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