Messages in this thread | | | Subject | Re: [PATCH RESEND v8 1/2] sched/numa: introduce per-cgroup NUMA locality info | From | 王贇 <> | Date | Mon, 24 Feb 2020 11:09:06 +0800 |
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On 2020/2/21 下午11:28, Peter Zijlstra wrote: > On Mon, Feb 17, 2020 at 09:23:52PM +0800, 王贇 wrote: >> FYI, by monitoring locality, we found that the kvm vcpu thread is not >> covered by NUMA Balancing, whatever how many maximum period passed, the >> counters are not increasing, or very slowly, although inside guest we are >> copying memory. >> >> Later we found such task rarely exit to user space to trigger task >> work callbacks, and NUMA Balancing scan depends on that, which help us >> realize the importance to enable NUMA Balancing inside guest, with the >> correct NUMA topo, a big performance risk I'll say :-P > > That's a bug in KVM, see: > > https://lkml.kernel.org/r/20190801143657.785902257@linutronix.de > https://lkml.kernel.org/r/20190801143657.887648487@linutronix.de > > ISTR there being newer versions of that patch-set, but I can't seem to > find them in a hurry.
Aha, that's exactly the problem we saw, will check~
Regards, Michael Wang
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