Re: [Xen-devel] [PATCH 1/1] sched/cputime: do not decrease steal time after live migration on xen

2017-10-11 Thread Dongli Zhang
Hi Rik, On 10/10/2017 10:01 PM, Rik van Riel wrote: > On Tue, 2017-10-10 at 14:48 +0200, Peter Zijlstra wrote: >> On Tue, Oct 10, 2017 at 02:42:01PM +0200, Stanislaw Gruszka wrote: > + u64 steal, steal_time; > + s64 steal_delta; > + > + steal_time = >

Re: [Xen-devel] [PATCH 1/1] sched/cputime: do not decrease steal time after live migration on xen

2017-10-11 Thread Dongli Zhang
Hi Stanislaw and Peter, On 10/10/2017 08:42 PM, Stanislaw Gruszka wrote: > On Tue, Oct 10, 2017 at 12:59:26PM +0200, Ingo Molnar wrote: >> >> (Cc:-ed more gents involved in kernel/sched/cputime.c work. Full patch >> quoted >> below.) >> >> * Dongli Zhang wrote: >> >>>

Re: [Xen-devel] [PATCH 1/1] sched/cputime: do not decrease steal time after live migration on xen

2017-10-10 Thread Rik van Riel
On Tue, 2017-10-10 at 14:48 +0200, Peter Zijlstra wrote: > On Tue, Oct 10, 2017 at 02:42:01PM +0200, Stanislaw Gruszka wrote: > > > > + u64 steal, steal_time; > > > > + s64 steal_delta; > > > > + > > > > + steal_time = > > > >

Re: [Xen-devel] [PATCH 1/1] sched/cputime: do not decrease steal time after live migration on xen

2017-10-10 Thread Peter Zijlstra
On Tue, Oct 10, 2017 at 02:42:01PM +0200, Stanislaw Gruszka wrote: > > > + u64 steal, steal_time; > > > + s64 steal_delta; > > > + > > > + steal_time = paravirt_steal_clock(smp_processor_id()); > > > + steal = steal_delta = steal_time - this_rq()->prev_steal_time; >

Re: [Xen-devel] [PATCH 1/1] sched/cputime: do not decrease steal time after live migration on xen

2017-10-10 Thread Stanislaw Gruszka
On Tue, Oct 10, 2017 at 12:59:26PM +0200, Ingo Molnar wrote: > > (Cc:-ed more gents involved in kernel/sched/cputime.c work. Full patch quoted > below.) > > * Dongli Zhang wrote: > > > After guest live migration on xen, steal time in /proc/stat > >

Re: [Xen-devel] [PATCH 1/1] sched/cputime: do not decrease steal time after live migration on xen

2017-10-10 Thread Peter Zijlstra
On Tue, Oct 10, 2017 at 05:14:08PM +0800, Dongli Zhang wrote: > After guest live migration on xen, steal time in /proc/stat > (cpustat[CPUTIME_STEAL]) might decrease because steal returned by > paravirt_steal_clock() might be less than this_rq()->prev_steal_time. So why not fix

Re: [Xen-devel] [PATCH 1/1] sched/cputime: do not decrease steal time after live migration on xen

2017-10-10 Thread Ingo Molnar
(Cc:-ed more gents involved in kernel/sched/cputime.c work. Full patch quoted below.) * Dongli Zhang wrote: > After guest live migration on xen, steal time in /proc/stat > (cpustat[CPUTIME_STEAL]) might decrease because steal returned by > paravirt_steal_clock() might

Re: [Xen-devel] [PATCH 1/1] sched/cputime: do not decrease steal time after live migration on xen

2017-10-10 Thread Jan Beulich
>>> On 10.10.17 at 11:14, wrote: > --- a/kernel/sched/cputime.c > +++ b/kernel/sched/cputime.c > @@ -238,10 +238,17 @@ static __always_inline u64 > steal_account_process_time(u64 maxtime) > { > #ifdef CONFIG_PARAVIRT > if (static_key_false(_steal_enabled)) { > -

[Xen-devel] [PATCH 1/1] sched/cputime: do not decrease steal time after live migration on xen

2017-10-10 Thread Dongli Zhang
After guest live migration on xen, steal time in /proc/stat (cpustat[CPUTIME_STEAL]) might decrease because steal returned by paravirt_steal_clock() might be less than this_rq()->prev_steal_time. For instance, steal time of each vcpu is 335 before live migration. cpu 198 0 368 200064 1962 0 0