Messages in this thread | | | Subject | Re: [RFC][PATCH 0/4] arm64:kvm: teach guest sched that VCPUs can be preempted | From | yezengruan <> | Date | Mon, 17 Aug 2020 20:03:09 +0800 |
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On 2020/8/17 10:03, Sergey Senozhatsky wrote: > On (20/07/21 13:17), Sergey Senozhatsky wrote: >> Hello, >> >> RFC >> >> We noticed that in a number of cases when we wake_up_process() >> on arm64 guest we end up enqueuing that task on a preempted VCPU. The culprit >> appears to be the fact that arm64 guests are not aware of VCPU preemption >> as such, so when sched picks up an idle VCPU it always assumes that VCPU >> is available: >> >> wake_up_process() >> try_to_wake_up() >> select_task_rq_fair() >> available_idle_cpu() >> vcpu_is_preempted() // return false; >> >> Which is, obviously, not the case. >> >> This RFC patch set adds a simple vcpu_is_preempted() implementation so >> that scheduler can make better decisions when it search for the idle >> (v)CPU. > Hi, > > A gentle ping. > > -ss > _______________________________________________ > kvmarm mailing list > kvmarm@lists.cs.columbia.edu > https://lists.cs.columbia.edu/mailman/listinfo/kvmarm > .
Hi Sergey,
I have a set of patches similar to yours.
https://lore.kernel.org/lkml/20191226135833.1052-1-yezengruan@huawei.com/
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