Re: [PATCH 20/25] sched/kcpustat: Introduce vtime-aware kcpustat accessor

2018-11-21 Thread Frederic Weisbecker
On Wed, Nov 21, 2018 at 09:18:19AM +0100, Peter Zijlstra wrote: > On Tue, Nov 20, 2018 at 11:40:22PM +0100, Frederic Weisbecker wrote: > > On Tue, Nov 20, 2018 at 03:23:06PM +0100, Peter Zijlstra wrote: > > > On Wed, Nov 14, 2018 at 03:46:04AM +0100, Frederic Weisbecker wrote: > > > > > > > +void

Re: [PATCH 20/25] sched/kcpustat: Introduce vtime-aware kcpustat accessor

2018-11-21 Thread Peter Zijlstra
On Wed, Nov 21, 2018 at 09:18:19AM +0100, Peter Zijlstra wrote: > On Tue, Nov 20, 2018 at 11:40:22PM +0100, Frederic Weisbecker wrote: > > On Tue, Nov 20, 2018 at 03:23:06PM +0100, Peter Zijlstra wrote: > > > On Wed, Nov 14, 2018 at 03:46:04AM +0100, Frederic Weisbecker wrote: > > > > > > > +void

Re: [PATCH 20/25] sched/kcpustat: Introduce vtime-aware kcpustat accessor

2018-11-21 Thread Peter Zijlstra
On Tue, Nov 20, 2018 at 11:40:22PM +0100, Frederic Weisbecker wrote: > On Tue, Nov 20, 2018 at 03:23:06PM +0100, Peter Zijlstra wrote: > > On Wed, Nov 14, 2018 at 03:46:04AM +0100, Frederic Weisbecker wrote: > > > > > +void kcpustat_cputime(struct kernel_cpustat *kcpustat, int cpu, > > > +

Re: [PATCH 20/25] sched/kcpustat: Introduce vtime-aware kcpustat accessor

2018-11-20 Thread Frederic Weisbecker
On Tue, Nov 20, 2018 at 03:23:06PM +0100, Peter Zijlstra wrote: > On Wed, Nov 14, 2018 at 03:46:04AM +0100, Frederic Weisbecker wrote: > > > +void kcpustat_cputime(struct kernel_cpustat *kcpustat, int cpu, > > + u64 *user, u64 *nice, u64 *system, > > + u64 *guest, u

Re: [PATCH 20/25] sched/kcpustat: Introduce vtime-aware kcpustat accessor

2018-11-20 Thread Peter Zijlstra
On Wed, Nov 14, 2018 at 03:46:04AM +0100, Frederic Weisbecker wrote: > +void kcpustat_cputime(struct kernel_cpustat *kcpustat, int cpu, > + u64 *user, u64 *nice, u64 *system, > + u64 *guest, u64 *guest_nice) > +{ > + struct task_struct *curr; > + struct

[PATCH 20/25] sched/kcpustat: Introduce vtime-aware kcpustat accessor

2018-11-13 Thread Frederic Weisbecker
Kcpustat is not correctly supported on nohz_full CPUs. The tick doesn't fire and the cputime therefore doesn't move forward. The issue has shown up after the vanishing of the remaining 1Hz which has made the issue visible. We are solving that with tracking the task running on a CPU through RCU and