[Cc-list edited] On Wed, 2015-11-25 at 08:58 +0000, Malcolm Crossley wrote: > On 24/11/15 18:30, George Dunlap wrote: > > On 24/11/15 18:16, George Dunlap wrote: > > > On 20/11/15 16:03, Malcolm Crossley wrote: > > > >  > > > > Removing the cache line bouncing on a multi-socket Haswell-EP > > > > system > > > > dramatically improves performance, with 16 vCPU network IO > > > > performance going > > > > from 15 gb/s to 64 gb/s! The host under test was fully > > > > utilising all 40 > > > > logical CPU's at 64 gb/s, so a bigger logical CPU host may see > > > > an even better > > > > IO improvement. > > > > > > Impressive -- thanks for doing this work. > > Thanks, I think the key to isolating the problem was using profiling > tools. The scale > of the overhead would not have been clear without them. > As an aside, if it's not too much work, a few hints and instruction on how such profiling has been done would be helpful for others and for the future. For example, a post on The Xen Project's blog about that (that then can be turned into a wiki page) would be awesome. :-) Regards, Dario -- <> (Raistlin Majere) ----------------------------------------------------------------- Dario Faggioli, Ph.D, http://about.me/dario.faggioli Senior Software Engineer, Citrix Systems R&D Ltd., Cambridge (UK)