Re: Steal time accounting in KVM. Benchmark.

Hi Paolo, On 10/24/15 10:03 AM, Alexey Makhalov wrote: 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

Re: Steal time accounting in KVM. Benchmark.

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.

Re: Steal time accounting in KVM. Benchmark.

'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%)

Re: Steal time accounting in KVM. Benchmark.

Yes, VM1 results are as before. Alexey On Tue, Oct 20, 2015 at 4:04 PM, Wanpeng Li 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

Re: Steal time accounting in KVM. Benchmark.

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

Steal time accounting in KVM. Benchmark.

Hi, I did benchmarking of scheduler fairness with enabled steal time accounting(STA) in KVM. And results are really interesting. Looks like STA provides worse scheduler fairness against disabled STA (no-steal-acc cmdline param) I created benchmark, main idea is: 2 cgroups with cpu.shares