Messages in this thread Patch in this message | | | Date | Fri, 30 Mar 2012 15:37:42 +0530 | From | Raghavendra K T <> | Subject | Re: [PATCH RFC V6 0/11] Paravirtualized ticketlocks |
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On 03/29/2012 11:33 PM, Raghavendra K T wrote: > On 03/29/2012 03:28 PM, Avi Kivity wrote: >> On 03/28/2012 08:21 PM, Raghavendra K T wrote:
> I really like below ideas. Thanks for that!. > >> - from the PLE handler, don't wake up a vcpu that is sleeping because it >> is waiting for a kick > > How about, adding another pass in the beginning of kvm_vcpu_on_spin() > to check if any vcpu is already kicked. This would almost result in > yield_to(kicked_vcpu). IMO this is also worth trying. > > will try above ideas soon. >
I have patch something like below in mind to try:
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index d3b98b1..5127668 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -1608,15 +1608,18 @@ void kvm_vcpu_on_spin(struct kvm_vcpu *me) * else and called schedule in __vcpu_run. Hopefully that * VCPU is holding the lock that we need and will release it. * We approximate round-robin by starting at the last boosted VCPU. + * Priority is given to vcpu that are unhalted. */ - for (pass = 0; pass < 2 && !yielded; pass++) { + for (pass = 0; pass < 3 && !yielded; pass++) { kvm_for_each_vcpu(i, vcpu, kvm) { struct task_struct *task = NULL; struct pid *pid; - if (!pass && i < last_boosted_vcpu) { + if (!pass && !vcpu->pv_unhalted) + continue; + else if (pass == 1 && i < last_boosted_vcpu) { i = last_boosted_vcpu; continue; - } else if (pass && i > last_boosted_vcpu) + } else if (pass == 2 && i > last_boosted_vcpu) break; if (vcpu == me) continue;
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