Re: [PATCH 1/2] vhost: allow multiple workers threads

On Mon, Feb 20, 2012 at 05:04:10PM -0800, Shirley Ma wrote:

On Mon, 2012-02-20 at 23:00 +0200, Michael S. Tsirkin wrote:

quoted

The point was really to avoid scheduler overhead
as with tcp, tx and rx tend to run on the same cpu.

We have tried different approaches in the past, like splitting vhost
thread to separate TX, RX threads; create per cpu vhost thread instead
of creating per VM per virtio_net vhost thread... 

We think per cpu vhost thread is a better approach based on the data we
have collected. It will reduce both vhost resource and scheduler
overhead. It will not depend on host scheduler, has less various. The
patch is under testing, we hope we can post it soon.

Thanks
Shirley

Yes, great, this is definitely interesting. I actually started with
a per-cpu one - it did not perform well but I did not
figure out why, switching to a single thread fixed it
and I did not dig into it.


-- 
MST