Messages in this thread | | | Subject | Re: [PATCH] vhost: Add polling mode | From | Razya Ladelsky <> | Date | Sun, 17 Aug 2014 15:35:39 +0300 |
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> > > > Hi Michael, > > > > Sorry for the delay, had some problems with my mailbox, and I realized
> > just now that > > my reply wasn't sent. > > The vm indeed ALWAYS utilized 100% cpu, whether polling was enabled or
> > not. > > The vhost thread utilized less than 100% (of the other cpu) when polling > > was disabled. > > Enabling polling increased its utilization to 100% (in which case both
> > cpus were 100% utilized). > > Hmm this means the testing wasn't successful then, as you said: > > The idea was to get it 100% loaded, so we can see that the polling is > getting it to produce higher throughput. > > in fact here you are producing more throughput but spending more power > to produce it, which can have any number of explanations besides polling > improving the efficiency. For example, increasing system load might > disable host power management. >
Hi Michael, I re-ran the tests, this time with the "turbo mode" and "C-states" features off. No Polling: 1 VM running netperf (msg size 64B): 1107 Mbits/sec Polling: 1 VM running netperf (msg size 64B): 1572 Mbits/sec
As you can see from the new results, the numbers are lower, but relatively (polling on/off) there's no change. Thank you, Razya
> > > > -- > > > MST > > > > -- > To unsubscribe from this list: send the line "unsubscribe kvm" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >
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