sched: Teach the forced-newidle balancer about CPU affinity limitation.
authorSebastian Andrzej Siewior <bigeasy@linutronix.de>
Thu, 17 Mar 2022 14:51:32 +0000 (15:51 +0100)
committerPeter Zijlstra <peterz@infradead.org>
Tue, 5 Apr 2022 07:59:36 +0000 (09:59 +0200)
commit386ef214c3c6ab111d05e1790e79475363abaa05
treec7711dcc2ec725393daf8ff5bae52b3b65712266
parent5b6547ed97f4f5dfc23f8e3970af6d11d7b7ed7e
sched: Teach the forced-newidle balancer about CPU affinity limitation.

try_steal_cookie() looks at task_struct::cpus_mask to decide if the
task could be moved to `this' CPU. It ignores that the task might be in
a migration disabled section while not on the CPU. In this case the task
must not be moved otherwise per-CPU assumption are broken.

Use is_cpu_allowed(), as suggested by Peter Zijlstra, to decide if the a
task can be moved.

Fixes: d2dfa17bc7de6 ("sched: Trivial forced-newidle balancer")
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/YjNK9El+3fzGmswf@linutronix.de
kernel/sched/core.c