Messages in this thread | | | Subject | Re: [RFC PATCH 1/1] vhost: TX used buffer guest signal accumulation | From | Sridhar Samudrala <> | Date | Thu, 28 Oct 2010 14:04:38 -0700 |
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On Thu, 2010-10-28 at 13:13 -0700, Shirley Ma wrote: > On Thu, 2010-10-28 at 12:32 -0700, Shirley Ma wrote: > > Also I found a big TX regression for old guest and new guest. For old > > guest, I am able to get almost 11Gb/s for 2K message size, but for the > > new guest kernel, I can only get 3.5 Gb/s with the patch and same > > host. > > I will dig it why. > > The regression is from guest kernel, not from this patch. Tested 2.6.31 > kernel, it's performance is less than 2Gb/s for 2K message size already. > I will resubmit the patch for review. > > I will start to test from 2.6.30 kernel to figure it when TX regression > induced in virtio_net. Any suggestion which guest kernel I should test > to figure out this regression?
It would be some change in virtio-net driver that may have improved the latency of small messages which in turn would have reduced the bandwidth as TCP could not accumulate and send large packets.
Thanks Sridhar
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