Re: [PATCH RFC] sched: Allow migrating kthreads into online but inactive CPUs

2017-07-26 Thread Paul E. McKenney
On Tue, Jul 25, 2017 at 06:58:21PM +0200, Peter Zijlstra wrote: > Hi, > > On Sat, Jun 17, 2017 at 08:10:08AM -0400, Tejun Heo wrote: > > Per-cpu workqueues have been tripping CPU affinity sanity checks while > > a CPU is being offlined. A per-cpu kworker ends up running on a CPU > > which isn't

Re: [PATCH RFC] sched: Allow migrating kthreads into online but inactive CPUs

2017-07-26 Thread Paul E. McKenney
On Tue, Jul 25, 2017 at 06:58:21PM +0200, Peter Zijlstra wrote: > Hi, > > On Sat, Jun 17, 2017 at 08:10:08AM -0400, Tejun Heo wrote: > > Per-cpu workqueues have been tripping CPU affinity sanity checks while > > a CPU is being offlined. A per-cpu kworker ends up running on a CPU > > which isn't

Re: [PATCH RFC] sched: Allow migrating kthreads into online but inactive CPUs

2017-07-25 Thread Paul E. McKenney
On Tue, Jul 25, 2017 at 06:58:21PM +0200, Peter Zijlstra wrote: > Hi, > > On Sat, Jun 17, 2017 at 08:10:08AM -0400, Tejun Heo wrote: > > Per-cpu workqueues have been tripping CPU affinity sanity checks while > > a CPU is being offlined. A per-cpu kworker ends up running on a CPU > > which isn't

Re: [PATCH RFC] sched: Allow migrating kthreads into online but inactive CPUs

2017-07-25 Thread Paul E. McKenney
On Tue, Jul 25, 2017 at 06:58:21PM +0200, Peter Zijlstra wrote: > Hi, > > On Sat, Jun 17, 2017 at 08:10:08AM -0400, Tejun Heo wrote: > > Per-cpu workqueues have been tripping CPU affinity sanity checks while > > a CPU is being offlined. A per-cpu kworker ends up running on a CPU > > which isn't

Re: [PATCH RFC] sched: Allow migrating kthreads into online but inactive CPUs

2017-07-25 Thread Peter Zijlstra
Hi, On Sat, Jun 17, 2017 at 08:10:08AM -0400, Tejun Heo wrote: > Per-cpu workqueues have been tripping CPU affinity sanity checks while > a CPU is being offlined. A per-cpu kworker ends up running on a CPU > which isn't its target CPU while the CPU is online but inactive. > > While the

Re: [PATCH RFC] sched: Allow migrating kthreads into online but inactive CPUs

2017-07-25 Thread Peter Zijlstra
Hi, On Sat, Jun 17, 2017 at 08:10:08AM -0400, Tejun Heo wrote: > Per-cpu workqueues have been tripping CPU affinity sanity checks while > a CPU is being offlined. A per-cpu kworker ends up running on a CPU > which isn't its target CPU while the CPU is online but inactive. > > While the

[PATCH RFC] sched: Allow migrating kthreads into online but inactive CPUs

2017-06-17 Thread Tejun Heo
Per-cpu workqueues have been tripping CPU affinity sanity checks while a CPU is being offlined. A per-cpu kworker ends up running on a CPU which isn't its target CPU while the CPU is online but inactive. While the scheduler allows kthreads to wake up on an online but inactive CPU, it doesn't

[PATCH RFC] sched: Allow migrating kthreads into online but inactive CPUs

2017-06-17 Thread Tejun Heo
Per-cpu workqueues have been tripping CPU affinity sanity checks while a CPU is being offlined. A per-cpu kworker ends up running on a CPU which isn't its target CPU while the CPU is online but inactive. While the scheduler allows kthreads to wake up on an online but inactive CPU, it doesn't