On Fri, 21 Sep 2012 17:30:20 +0530
Raghavendra K T <raghavendra...@linux.vnet.ibm.com> wrote:
> From: Raghavendra K T <raghavendra...@linux.vnet.ibm.com>
>
> 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 <sri...@linux.vnet.ibm.com>
> Signed-off-by: Raghavendra K T <raghavendra...@linux.vnet.ibm.com>
> ---
> 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 majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
