Messages in this thread | | | From | Wanpeng Li <> | Date | Wed, 6 Jul 2016 16:32:07 +0800 | Subject | Re: [PATCH v2 2/4] powerpc/spinlock: support vcpu preempted check |
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2016-07-06 15:58 GMT+08:00 Peter Zijlstra <peterz@infradead.org>: > On Wed, Jul 06, 2016 at 02:46:34PM +0800, Wanpeng Li wrote: >> > SO it's easy for ppc to implement such interface. Note that yield_count is >> > set by powerVM/KVM. >> > and only pSeries can run a guest for now. :) >> > >> > I also review x86 related code, looks like we need add one hyer-call to get >> > such vcpu preemption info? >> >> There is no such stuff to record lock holder in x86 kvm, maybe we >> don't need to depend on PLE handler algorithm to guess it if we can >> know lock holder vCPU directly. > > x86/kvm has vcpu->preempted to indicate if a vcpu is currently preempted > or not. I'm just not sure if that is visible to the guest or how to make > it so.
Yeah, I miss it. I can be the volunteer to do it if there is any idea, ping Paolo. :)
Regards, Wanpeng Li
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