sched/fair: Do strict inequality check for busiest misfit task group

In update_sd_pick_busiest(), when comparing two sched groups that are
both of type group_misfit_task, we currently consider the new group as
busier than the current busiest group even if the new group has the
same misfit task load as the current busiest group. We can avoid some
unnecessary writes if we instead only consider the newest group to be
the busiest if it has a higher load than the current busiest. This
matches the behavior of other group types where we compare load, such as
two groups that are both overloaded.

Let's update the group_misfit_task type comparison to also only update
the busiest group in the event of strict inequality.

Signed-off-by: David Vernet <void@manifault.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>
Reviewed-by: Valentin Schneider <vschneid@redhat.com>
Link: https://lore.kernel.org/r/20240206043921.850302-3-void@manifault.com
This commit is contained in:
David Vernet 2024-02-05 22:39:20 -06:00 committed by Ingo Molnar
parent 9dfbc26d27
commit 7f1a722971

View file

@ -10032,7 +10032,7 @@ static bool update_sd_pick_busiest(struct lb_env *env,
* If we have more than one misfit sg go with the biggest
* misfit.
*/
if (sgs->group_misfit_task_load < busiest->group_misfit_task_load)
if (sgs->group_misfit_task_load <= busiest->group_misfit_task_load)
return false;
break;