On 06/20/2012 04:12 PM, Raghavendra K T wrote:
On 06/20/2012 02:21 AM, Rik van Riel wrote:
Please let me know how it goes.
Yes, have got result today, too tired to summarize. got better
performance result too. will come back again tomorrow morning.
have to post, randomized start point patch also, which I discussed to
know the opinion.
The other person's problem has also gone away with this
patch.
Avi, could I convince you to apply this obvious bugfix
to kvm.git? :)
====8<====
If last_boosted_vcpu == 0, then we fall through all test cases and
may end up with all VCPUs pouncing on vcpu 0. With a large enough
guest, this can result in enormous runqueue lock contention, which
can prevent vcpu0 from running, leading to a livelock.
Changing< to<= makes sure we properly handle that case.
Signed-off-by: Rik van Riel<riel@xxxxxxxxxx>
---
virt/kvm/kvm_main.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 7e14068..1da542b 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -1586,7 +1586,7 @@ void kvm_vcpu_on_spin(struct kvm_vcpu *me)
*/
for (pass = 0; pass< 2&& !yielded; pass++) {
kvm_for_each_vcpu(i, vcpu, kvm) {
- if (!pass&& i< last_boosted_vcpu) {
+ if (!pass&& i<= last_boosted_vcpu) {
i = last_boosted_vcpu;
continue;
} else if (pass&& i> last_boosted_vcpu)
--
All rights reversed
--
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
