On Wed, Apr 28, 2010 at 01:57:12PM -0700, David L Stevens wrote: > This patch adds mergeable receive buffer support to vhost_net. > > Signed-off-by: David L Stevens <dlstevens@xxxxxxxxxx> I've been doing some more testing before sending out a pull request, and I see a drastic performance degradation in guest to host traffic when this is applied but mergeable buffers are not in used by userspace (existing qemu-kvm userspace). This is both with and without my patch on top. Without patch: [mst@tuck ~]$ sh runtest 2>&1 | tee ser-meregeable-disabled-kernel-only-tun-only.log Starting netserver at port 12865 set_up_server could not establish a listen endpoint for port 12865 with family AF_UNSPEC TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 11.0.0.4 (11.0.0.4) port 0 AF_INET : demo Recv Send Send Utilization Service Demand Socket Socket Message Elapsed Send Recv Send Recv Size Size Size Time Throughput local remote local remote bytes bytes bytes secs. 10^6bits/s % S % S us/KB us/KB 87380 16384 16384 10.00 9107.26 89.20 33.85 0.802 2.436 With patch: TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 11.0.0.4 (11.0.0.4) port 0 AF_INET : demo Recv Send Send Utilization Service Demand Socket Socket Message Elapsed Send Recv Send Recv Size Size Size Time Throughput local remote local remote bytes bytes bytes secs. 10^6bits/s % S % S us/KB us/KB 87380 16384 16384 10.00 35.00 2.21 0.62 5.181 11.575 For ease of testing, I put this on my tree git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost.git vhost-broken Please take a look. Thanks! -- MST -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
