On Fri, 21 Sep 2012 17:30:20 +0530 Raghavendra K T <raghavendra.kt@xxxxxxxxxxxxxxxxxx> wrote: > From: Raghavendra K T <raghavendra.kt@xxxxxxxxxxxxxxxxxx> > > When PLE handler fails to find a better candidate to yield_to, it > goes back and does spin again. This is acceptable when we do not > have overcommit. > But in overcommitted scenarios (especially when we have large > number of small guests), it is better to yield. > > Reviewed-by: Srikar Dronamraju <srikar@xxxxxxxxxxxxxxxxxx> > Signed-off-by: Raghavendra K T <raghavendra.kt@xxxxxxxxxxxxxxxxxx> > --- > virt/kvm/kvm_main.c | 4 ++++ > 1 files changed, 4 insertions(+), 0 deletions(-) > > diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c > index 8323685..713b677 100644 > --- a/virt/kvm/kvm_main.c > +++ b/virt/kvm/kvm_main.c > @@ -1660,6 +1660,10 @@ void kvm_vcpu_on_spin(struct kvm_vcpu *me) > } > } > } > + /* In overcommitted cases, yield instead of spinning */ > + if (!yielded && rq_nr_running() > 1) > + schedule(); How about doing cond_resched() instead? I'm not sure whether checking more sched stuff in KVM code is a good thing. Takuya -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
