Messages in this thread | | | Date | Sat, 4 Dec 2021 10:40:40 +0100 | From | Peter Zijlstra <> | Subject | Re: [PATCH v3] sched/fair: Fix per-CPU kthread and wakee stacking for asym CPU capacity |
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On Mon, Nov 29, 2021 at 05:31:15PM +0000, Vincent Donnefort wrote: > select_idle_sibling() has a special case for tasks woken up by a per-CPU > kthread where the selected CPU is the previous one. For asymmetric CPU > capacity systems, the assumption was that the wakee couldn't have a > bigger utilization during task placement than it used to have during the > last activation. That was not considering uclamp.min which can completely > change between two task activations and as a consequence mandates the > fitness criterion asym_fits_capacity(), even for the exit path described > above. > > Fixes: b4c9c9f15649 ("sched/fair: Prefer prev cpu in asymmetric wakeup path") > Signed-off-by: Vincent Donnefort <vincent.donnefort@arm.com> > Reviewed-by: Valentin Schneider <valentin.schneider@arm.com> > Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Thanks!
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