Comment 12 for bug 1066055

Revision history for this message
Anthony Liguori (anthony-codemonkey) wrote : Re: [PATCH] virtio: limit avail bytes lookahead

"Michael S. Tsirkin" <email address hidden> writes:

> On Thu, Nov 29, 2012 at 06:34:46PM +0530, Amit Shah wrote:
>> On (Wed) 28 Nov 2012 [23:53:08], Michael S. Tsirkin wrote:
>> > On Tue, Nov 27, 2012 at 06:25:04PM +0200, Michael S. Tsirkin wrote:
>> > > On Thu, Nov 01, 2012 at 06:07:21PM +0200, Michael S. Tsirkin wrote:
>> > > > Commit 0d8d7690850eb0cf2b2b60933cf47669a6b6f18f introduced
>> > > > a regression in virtio-net performance because it looks
>> > > > into the ring aggressively while we really only care
>> > > > about a single packet worth of buffers.
>> > > > To fix, add parameters limiting lookahead, and
>> > > > use in virtqueue_avail_bytes.
>> > > >
>> > > > Signed-off-by: Michael S. Tsirkin <email address hidden>
>> > > > Reported-by: Edivaldo de Araujo Pereira <email address hidden>
>> > >
>> > > Ping.
>> > > Anthony - going to apply this?
>> >
>> > virtio rng was added since so naturally build broke.
>> > Here's a patch on top to fix it up. I never used virtio rng before so
>> > could not test at this hour, but it does fix the build.
>> >
>> > I'll take a look at how to test it tomorrow but any
>> > info would be appreciated.
>> > Amit could you pls review?
>>
>> Looks fine, I assume you will send a v2 of the patch to Anthony?
>>
>> Amit
>
>
> Anthony volunteered to test this so there will only be v2 if he sees
> problems.

I need a Signed-off-by so why don't you just go ahead and send a v2 and
I'll test that.

Regards,

Anthony Liguori