Michael S. Tsirkin m...@redhat.com wrote on 10/12/2010 10:39:07 PM:
Sorry for the delay, I was sick last couple of days. The results
with your patch are (%'s over original code):
Code BW% CPU% RemoteCPU
MQ (#txq=16) 31.4% 38.42% 6.41%
MQ+MST
On Thu, Oct 14, 2010 at 01:28:58PM +0530, Krishna Kumar2 wrote:
Michael S. Tsirkin m...@redhat.com wrote on 10/12/2010 10:39:07 PM:
Sorry for the delay, I was sick last couple of days. The results
with your patch are (%'s over original code):
Code BW% CPU%
Michael S. Tsirkin m...@redhat.com
What other shared TX/RX locks are there? In your setup, is the same
macvtap socket structure used for RX and TX? If yes this will create
cacheline bounces as sk_wmem_alloc/sk_rmem_alloc share a cache line,
there might also be contention on the lock
Krishna Kumar2/India/IBM wrote on 10/14/2010 02:34:01 PM:
void vhost_poll_queue(struct vhost_poll *poll)
{
struct vhost_virtqueue *vq = vhost_find_vq(poll);
vhost_work_queue(vq, poll-work);
}
Since poll batches packets, find_vq does not seem to add much
to the CPU
Krishna Kumar2/India/IBM wrote on 10/14/2010 05:47:54 PM:
Sorry, it should read txq=8 below.
- KK
There's a significant reduction in CPU/SD utilization with your
patch. Following is the performance of ORG vs MQ+mm patch:
_
Org
Michael S. Tsirkin m...@redhat.com wrote on 10/06/2010 07:04:31 PM:
On Fri, Sep 17, 2010 at 03:33:07PM +0530, Krishna Kumar wrote:
For 1 TCP netperf, I ran 7 iterations and summed it. Explanation
for degradation for 1 stream case:
I thought about possible RX/TX contention reasons, and I
On Tuesday 05 October 2010, Krishna Kumar2 wrote:
After testing various combinations of #txqs, #vhosts, #netperf
sessions, I think the drop for 1 stream is due to TX and RX for
a flow being processed on different cpus. I did two more tests:
1. Pin vhosts to same CPU:
- BW drop is
On Fri, Sep 17, 2010 at 03:33:07PM +0530, Krishna Kumar wrote:
For 1 TCP netperf, I ran 7 iterations and summed it. Explanation
for degradation for 1 stream case:
I thought about possible RX/TX contention reasons, and I realized that
we get/put the mm counter all the time. So I write the
...@codemonkey.ws
Subject
Re: [v2 RFC PATCH 0/4] Implement multiqueue virtio-net
On Fri, Sep 17, 2010 at 03:33:07PM +0530, Krishna Kumar wrote:
For 1 TCP netperf, I ran 7 iterations and summed it. Explanation
for degradation for 1 stream case:
I thought about possible RX/TX contention
Arnd Bergmann a...@arndb.de wrote on 10/06/2010 05:49:00 PM:
I don't see any reasons mentioned above. However, for higher
number of netperf sessions, I see a big increase in retransmissions:
___
#netperf ORG NEW
BW (#retr)
Michael S. Tsirkin m...@redhat.com wrote on 10/05/2010 11:53:23 PM:
Any idea where does this come from?
Do you see more TX interrupts? RX interrupts? Exits?
Do interrupts bounce more between guest CPUs?
4. Identify reasons for single netperf BW regression.
After testing various
On Wednesday 06 October 2010 19:14:42 Krishna Kumar2 wrote:
Arnd Bergmann a...@arndb.de wrote on 10/06/2010 05:49:00 PM:
I don't see any reasons mentioned above. However, for higher
number of netperf sessions, I see a big increase in retransmissions:
On Wed, Oct 06, 2010 at 11:13:31PM +0530, Krishna Kumar2 wrote:
Michael S. Tsirkin m...@redhat.com wrote on 10/05/2010 11:53:23 PM:
Any idea where does this come from?
Do you see more TX interrupts? RX interrupts? Exits?
Do interrupts bounce more between guest CPUs?
4. Identify
Michael S. Tsirkin m...@redhat.com wrote on 09/19/2010 06:14:43 PM:
Could you document how exactly do you measure multistream bandwidth:
netperf flags, etc?
All results were without any netperf flags or system tuning:
for i in $list
do
netperf -c -C -l 60 -H 192.168.122.1
On Tue, Oct 05, 2010 at 04:10:00PM +0530, Krishna Kumar2 wrote:
Michael S. Tsirkin m...@redhat.com wrote on 09/19/2010 06:14:43 PM:
Could you document how exactly do you measure multistream bandwidth:
netperf flags, etc?
All results were without any netperf flags or system tuning:
On Fri, Sep 17, 2010 at 03:33:07PM +0530, Krishna Kumar wrote:
For 1 TCP netperf, I ran 7 iterations and summed it. Explanation
for degradation for 1 stream case:
Could you document how exactly do you measure multistream bandwidth:
netperf flags, etc?
1. Without any tuning, BW falls
Following patches implement transmit MQ in virtio-net. Also
included is the user qemu changes. MQ is disabled by default
unless qemu specifies it.
1. This feature was first implemented with a single vhost.
Testing showed 3-8% performance gain for upto 8 netperf
sessions (and sometimes 16),
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