What I figured out. It happens in intersection of 3 features: *irq time accounting *stolen time accounting *linux guest with tickless idle only (not fully tickless) Looks like timer interrupts storm is happening during this benchmark (with 2:1 cpu overcommit). irq time accounting gets crazy. Even 'top' shows weird statistic: 50% hi, 50% st, ~0% user, spinning processes use ~0% cpu - that is not correct. Thanks. On Tue, Oct 20, 2015 at 5:24 PM, Alexey Makhalov <makhaloff@xxxxxxxxx> wrote: > Yes, VM1 results are as before. > > Alexey > > On Tue, Oct 20, 2015 at 4:04 PM, Wanpeng Li <wanpeng.li@xxxxxxxxxxx> wrote: >> On 10/21/15 4:05 AM, Alexey Makhalov wrote: >>> >>> 'echo NO_NONTASK_CAPACITY > /sys/kernel/debug/sched_features' in both >>> guests. >>> Results: >>> VM1: STA is disabled -- no changes, still little bit bellow expected 90% >>> VM2: STA is enabled -- result is changed, but still bad. Hard to say >>> better or worse. It prefers to stuck at quarters (100% 75% 50% 25%) >>> Output is attached. >> >> >> If the output in attachment is for VM2 only? >> >> Regards, >> Wanpeng Li -- 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
