On Thu, Oct 22, 2015 at 08:46:33AM -0700, Rick Jones wrote: > On 10/22/2015 02:33 AM, Michael S. Tsirkin wrote: > >On Thu, Oct 22, 2015 at 01:27:29AM -0400, Jason Wang wrote: > >>This patch tries to poll for new added tx buffer for a while at the > >>end of tx processing. The maximum time spent on polling were limited > >>through a module parameter. To avoid block rx, the loop will end it > >>there's new other works queued on vhost so in fact socket receive > >>queue is also be polled. > >> > >>busyloop_timeout = 50 gives us following improvement on TCP_RR test: > >> > >>size/session/+thu%/+normalize% > >> 1/ 1/ +5%/ -20% > >> 1/ 50/ +17%/ +3% > > > >Is there a measureable increase in cpu utilization > >with busyloop_timeout = 0? > > And since a netperf TCP_RR test is involved, be careful about what netperf > reports for CPU util if that increase isn't in the context of the guest OS. > > For completeness, looking at the effect on TCP_STREAM and TCP_MAERTS, > aggregate _RR and even aggregate _RR/packets per second for many VMs on the > same system would be in order. > > happy benchmarking, > > rick jones Absolutely, merging a new kernel API just for a specific benchmark doesn't make sense. I'm guessing this is just an early RFC, a fuller submission will probably include more numbers. -- 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
