Re: [PATCH 11/20] sched: Handle CPU isolation on last resort fallback rq selection

2024-10-28 Thread Frederic Weisbecker
Le Mon, Oct 28, 2024 at 04:25:15PM +, Will Deacon a écrit : > > If nohz_full= isn't used then > > it's cpu_possible_mask). If there is a housekeeping CPU supporting el0 > > 32bits > > then it will be disallowed to be ever offlined. But if the first mismatching > > CPU supporting el0 that pops

Re: [PATCH 11/20] sched: Handle CPU isolation on last resort fallback rq selection

2024-10-28 Thread Will Deacon
Hi Frederic, Thanks for having a crack at this, but I'm pretty confused now so please prepare for a bunch of silly questions! On Tue, Oct 15, 2024 at 03:48:55PM +0200, Frederic Weisbecker wrote: > Le Tue, Oct 08, 2024 at 11:54:35AM +0100, Will Deacon a écrit : > > On Fri, Sep 27, 2024 at 12:48:59

Re: [PATCH 11/20] sched: Handle CPU isolation on last resort fallback rq selection

2024-10-15 Thread Frederic Weisbecker
Le Tue, Oct 08, 2024 at 11:54:35AM +0100, Will Deacon a écrit : > On Fri, Sep 27, 2024 at 12:48:59AM +0200, Frederic Weisbecker wrote: > > When a kthread or any other task has an affinity mask that is fully > > offline or unallowed, the scheduler reaffines the task to all possible > > CPUs as a las

Re: [PATCH 11/20] sched: Handle CPU isolation on last resort fallback rq selection

2024-10-08 Thread Frederic Weisbecker
Le Tue, Oct 08, 2024 at 11:54:35AM +0100, Will Deacon a écrit : > On Fri, Sep 27, 2024 at 12:48:59AM +0200, Frederic Weisbecker wrote: > > When a kthread or any other task has an affinity mask that is fully > > offline or unallowed, the scheduler reaffines the task to all possible > > CPUs as a las

Re: [PATCH 11/20] sched: Handle CPU isolation on last resort fallback rq selection

2024-10-08 Thread Will Deacon
On Fri, Sep 27, 2024 at 12:48:59AM +0200, Frederic Weisbecker wrote: > When a kthread or any other task has an affinity mask that is fully > offline or unallowed, the scheduler reaffines the task to all possible > CPUs as a last resort. > > This default decision doesn't mix up very well with nohz_

Re: [PATCH 11/20] sched: Handle CPU isolation on last resort fallback rq selection

2024-09-27 Thread Michal Hocko
On Fri 27-09-24 00:48:59, Frederic Weisbecker wrote: > When a kthread or any other task has an affinity mask that is fully > offline or unallowed, the scheduler reaffines the task to all possible > CPUs as a last resort. > > This default decision doesn't mix up very well with nohz_full CPUs that >

[PATCH 11/20] sched: Handle CPU isolation on last resort fallback rq selection

2024-09-26 Thread Frederic Weisbecker
When a kthread or any other task has an affinity mask that is fully offline or unallowed, the scheduler reaffines the task to all possible CPUs as a last resort. This default decision doesn't mix up very well with nohz_full CPUs that are part of the possible cpumask but don't want to be disturbed