Hello Peter, Lai Sorry to disturb again, I'm still confused, when the CPU is offline, we active call set_cpus_allowed_ptr function to reset per-cpu kthread cpumask, in sched_cpu_dying function , migrate_tasks function will reset per-cpu kthread's cpumask on runq, even if not on runq, when wake up, other online CPUs will also be selected to run.
what I want to ask is why we take the initiative to set it up? Thanks Qiang ________________________________________ 发件人: Peter Zijlstra <[email protected]> 发送时间: 2021年1月14日 17:11 收件人: Zhang, Qiang 抄送: [email protected] 主题: Re: Question on workqueue: Manually break affinity on hotplug [Please note this e-mail is from an EXTERNAL e-mail address] On Thu, Jan 14, 2021 at 08:03:23AM +0000, Zhang, Qiang wrote: > Hello Peter > > Excuse me, I have some questions for you, about a description of this change: > > ''Don't rely on the scheduler to force break affinity for us -- it will > stop doing that for per-cpu-kthreads." > > this mean when cpuhotplug, scheduler do not change affinity for > per-cpu-kthread's task, if we not active setting affinity? > but if per-cpu-kthread's task is not run state, when wake up, will reset > it's affinity, this is done automatically. > > or is it, this place modified to fit the new one hotplug mechanism which > ("sched/hotplug: Consolidate task migration on CPU unplug")? https://lkml.kernel.org/r/[email protected] https://lkml.kernel.org/r/[email protected] https://lkml.kernel.org/r/[email protected] https://lkml.kernel.org/r/[email protected] https://lkml.kernel.org/r/[email protected]
