Re: [PATCH net-next V2 0/3] rx busy polling support for virtio-net

On 07/21/2014 04:34 AM, Michael S. Tsirkin wrote:

On Wed, Jul 16, 2014 at 02:21:44PM +0800, Jason Wang wrote:

quoted

Hi all:

This series introduces the support for rx busy polling support. This
was useful for reduing the latency for a kvm guest. Patch 1-2
introduces helpers which is used for rx busy polling. Patch 3
implement the main function.

Test was done between a kvm guest and an external host. Two hosts were
connected through 40gb mlx4 cards. With both busy_poll and busy_read are
set to 50 in guest, 1 byte netperf tcp_rr shows 116% improvement:
transaction rate was increased from 9151.94 to 19787.37.

Changes from V1:
- split the patch info smaller ones
- add more details about test setup/configuration

Please review.

Generally I think we should let host know we are polling.
For example, kick the rq or something. Or maybe add another
io address.

Yes, I'm also working on busy polling for tun and vhost which may also
help here.

Something like this would need a new feature flag though, so I'm fine
with just polling in guest until that is available.

Yes.

quoted

Jason Wang (3):
  virtio-net: introduce helpers to enable and disable all NAPIs
  virtio-net: introduce virtnet_receive()
  virtio-net: rx busy polling support

 drivers/net/virtio_net.c | 234 ++++++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 221 insertions(+), 13 deletions(-)

-- 
1.8.3.1

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