Messages in this thread | | | Date | Fri, 7 May 2021 19:09:12 -0300 | From | Marcelo Tosatti <> | Subject | Re: [PATCH] Revert "isolcpus: Affine unbound kernel threads to housekeeping cpus" |
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On Fri, May 07, 2021 at 10:16:00PM +0200, Frederic Weisbecker wrote: > On Fri, May 07, 2021 at 01:57:10PM -0300, Marcelo Tosatti wrote: > > > > > > commit 9cc5b8656892a72438ee7deb introduced a new housekeeping flag, > > HK_FLAG_KTHREAD, that when enabled sets the CPU affinity for the > > kthreadd process (therefore all unbounded kernel threads created > > from that point on will use the housekeeping cpumask). > > > > This is not necessary, since its possible to control placement of > > kthreadd from userspace: > > > > # taskset -c -p 0 `pgrep kthreadd` > > pid 2's current affinity list: 1 > > pid 2's new affinity list: 0 > > > > Unbounded kernel threads started from that point on will inherit > > the kthreadd cpumask. > > Hmm, but look below: > > > @@ -405,8 +404,7 @@ struct task_struct *__kthread_create_on_ > > * The kernel thread should not inherit these properties. > > */ > > sched_setscheduler_nocheck(task, SCHED_NORMAL, ¶m); > > - set_cpus_allowed_ptr(task, > > - housekeeping_cpumask(HK_FLAG_KTHREAD)); > > + set_cpus_allowed_ptr(task, cpu_possible_mask); > > That inheritance is then overriden, right? > > Thanks.
Hi Frederic,
Doh, yes, ignore me.
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