Re: [PATCH -tip 10/32] sched: Fix priority inversion of cookied task with sibling

2020-12-01 Thread Joel Fernandes
On Thu, Nov 26, 2020 at 10:05:19AM +1100, Balbir Singh wrote: > On Tue, Nov 24, 2020 at 01:30:38PM -0500, Joel Fernandes wrote: > > On Mon, Nov 23, 2020 at 09:41:23AM +1100, Balbir Singh wrote: > > > On Tue, Nov 17, 2020 at 06:19:40PM -0500, Joel Fernandes (Google) wrote: > > > > From: Peter

Re: [PATCH -tip 10/32] sched: Fix priority inversion of cookied task with sibling

2020-11-26 Thread Balbir Singh
On Thu, Nov 26, 2020 at 09:29:14AM +0100, Peter Zijlstra wrote: > On Thu, Nov 26, 2020 at 10:05:19AM +1100, Balbir Singh wrote: > > > @@ -5259,7 +5254,20 @@ pick_next_task(struct rq *rq, struct task_struct > > > *prev, struct rq_flags *rf) > > >* Optimize the 'normal' case

Re: [PATCH -tip 10/32] sched: Fix priority inversion of cookied task with sibling

2020-11-26 Thread Peter Zijlstra
On Thu, Nov 26, 2020 at 10:05:19AM +1100, Balbir Singh wrote: > > @@ -5259,7 +5254,20 @@ pick_next_task(struct rq *rq, struct task_struct > > *prev, struct rq_flags *rf) > > * Optimize the 'normal' case where there aren't any > > * cookies and we don't

Re: [PATCH -tip 10/32] sched: Fix priority inversion of cookied task with sibling

2020-11-25 Thread Balbir Singh
On Tue, Nov 24, 2020 at 01:30:38PM -0500, Joel Fernandes wrote: > On Mon, Nov 23, 2020 at 09:41:23AM +1100, Balbir Singh wrote: > > On Tue, Nov 17, 2020 at 06:19:40PM -0500, Joel Fernandes (Google) wrote: > > > From: Peter Zijlstra > > > > > > The rationale is as follows. In the core-wide pick

Re: [PATCH -tip 10/32] sched: Fix priority inversion of cookied task with sibling

2020-11-24 Thread Joel Fernandes
On Mon, Nov 23, 2020 at 09:41:23AM +1100, Balbir Singh wrote: > On Tue, Nov 17, 2020 at 06:19:40PM -0500, Joel Fernandes (Google) wrote: > > From: Peter Zijlstra > > > > The rationale is as follows. In the core-wide pick logic, even if > > need_sync == false, we need to go look at other CPUs

Re: [PATCH -tip 10/32] sched: Fix priority inversion of cookied task with sibling

2020-11-22 Thread Balbir Singh
On Tue, Nov 17, 2020 at 06:19:40PM -0500, Joel Fernandes (Google) wrote: > From: Peter Zijlstra > > The rationale is as follows. In the core-wide pick logic, even if > need_sync == false, we need to go look at other CPUs (non-local CPUs) to > see if they could be running RT. > > Say the RQs in

[PATCH -tip 10/32] sched: Fix priority inversion of cookied task with sibling

2020-11-17 Thread Joel Fernandes (Google)
From: Peter Zijlstra The rationale is as follows. In the core-wide pick logic, even if need_sync == false, we need to go look at other CPUs (non-local CPUs) to see if they could be running RT. Say the RQs in a particular core look like this: Let CFS1 and CFS2 be 2 tagged CFS tags. Let RT1 be an