[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Xen-devel] [PATCH 0/4] Implement persistent grant in xen-netfront/netback





On 2012-11-15 16:51, Ian Campbell wrote:
On Thu, 2012-11-15 at 08:38 +0000, ANNIE LI wrote:
On 2012-11-15 15:40, Pasi KÃrkkÃinen 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
Are these pairs of guests or individual ones?

They are pairs of guests.


I think the really interesting cases are when you get up to larger
numbers of guests, aren't they?
Right.
ISTR that for blkio things got most
interesting WRT persistent grants at the dozens of guests stage. Do you
have any numbers for those?
No, I will run more test with more gusets.

Have you run any tests other than netperf?
No, I didn't.

Do you have numbers for a a persistent capable backend with a
non-persistent frontend and vice versa?
I did it, but the test only runs with 4 guests tooïwill test with more guests.

Thanks
Annie



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


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel

 


Rackspace

Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.