Re: [PATCH] KVM: add halt_attempted_poll to VCPU stats

2015-09-17 Thread David Hildenbrand
> Am 15.09.2015 um 18:27 schrieb Paolo Bonzini: > > This new statistic can help diagnosing VCPUs that, for any reason, > > trigger bad behavior of halt_poll_ns autotuning. > > > > For example, say halt_poll_ns = 48, and wakeups are spaced exactly > > like 479us, 481us, 479us, 481us. Then KVM

Re: [PATCH] KVM: add halt_attempted_poll to VCPU stats

2015-09-16 Thread Paolo Bonzini
On 16/09/2015 12:12, Christian Borntraeger wrote: > I am looking into a case right now, where auto polling goes > completely nuts on my system: > > guest1: 8vcpusguest2: 1 vcpu > iperf with 25 process (-P25) from guest1 to guest2. > > I/O interrupts on s390 are floating

Re: [PATCH] KVM: add halt_attempted_poll to VCPU stats

2015-09-16 Thread Christian Borntraeger
Am 15.09.2015 um 18:27 schrieb Paolo Bonzini: > This new statistic can help diagnosing VCPUs that, for any reason, > trigger bad behavior of halt_poll_ns autotuning. > > For example, say halt_poll_ns = 48, and wakeups are spaced exactly > like 479us, 481us, 479us, 481us. Then KVM always fails

Re: [PATCH] KVM: add halt_attempted_poll to VCPU stats

2015-09-16 Thread Wanpeng Li
On 9/16/15 6:12 PM, Christian Borntraeger wrote: Am 15.09.2015 um 18:27 schrieb Paolo Bonzini: This new statistic can help diagnosing VCPUs that, for any reason, trigger bad behavior of halt_poll_ns autotuning. For example, say halt_poll_ns = 48, and wakeups are spaced exactly like 479us,

Re: [PATCH] KVM: add halt_attempted_poll to VCPU stats

2015-09-15 Thread David Matlack
On Tue, Sep 15, 2015 at 9:27 AM, Paolo Bonzini wrote: > This new statistic can help diagnosing VCPUs that, for any reason, > trigger bad behavior of halt_poll_ns autotuning. > > For example, say halt_poll_ns = 48, and wakeups are spaced exactly > like 479us, 481us, 479us,