On Thu, Nov 15, 2012 at 4:38 PM, ANNIE LI <annie.li@xxxxxxxxxx
<mailto:annie.li@xxxxxxxxxx>> wrote:
On 2012-11-15 15:40, Pasi Kärkkäinen wrote:
Hello,
On Thu, Nov 15, 2012 at 03:03:07PM +0800, Annie Li wrote:
This patch implements persistent grants for
xen-netfront/netback. This
mechanism maintains page pools in netback/netfront, these
page pools is used to
save grant pages which are mapped. This way improve
performance which is wasted
when doing grant operations.
Current netback/netfront does map/unmap grant operations
frequently when
transmitting/receiving packets, and grant operations costs
much cpu clock. In
this patch, netfront/netback maps grant pages when needed
and then saves them
into a page pool for future use. All these pages will be
unmapped when
removing/releasing the net device.
Do you have performance numbers available already?
with/without persistent grants?
I have some simple netperf/netserver test result with/without
persistent grants,
Following is result of with persistent grant patch,
Guests, Sum, Avg, Min, Max
1, 15106.4, 15106.4, 15106.36, 15106.36
2, 13052.7, 6526.34, 6261.81, 6790.86
3, 12675.1, 6337.53, 6220.24, 6454.83
4, 13194, 6596.98, 6274.70, 6919.25
Following are result of without persistent patch
Guests, Sum, Avg, Min, Max
1, 10864.1, 10864.1, 10864.10, 10864.10
2, 10898.5, 5449.24, 4862.08, 6036.40
3, 10734.5, 5367.26, 5261.43, 5473.08
4, 10924, 5461.99, 5314.84, 5609.14
Interesting results. Have you tested how good it is on a 10G nic, i.e.
guest sending packets
through physical network to another host.
