Commit ee8cf2ef authored Sep 10, 2018 by Lingutla Chandrasekhar

sched: avoid energy evaluation for isolated prev_cpu



If task placement algorithm is not able to find efficient cpu,
it bias towards prev_cpu. If prev_cpu is isolated then, we use one
of non-isolated task allowed cpu and skip energy evaluations.
If we find efficient or backup cpu, prev_cpu is isolated then still it
is used for energy evaluations, which is not needed.

If prev_cpu isolated, set eenv flag independent of target_cpu to avoid
unnecessary energy evaluations.

Change-Id: I884d0e224b2f40157ef55fd429e138cf66eb6de1
Signed-off-by: Lingutla Chandrasekhar <clingutla@codeaurora.org>

parent 75a3c4ec

kernel/sched/fair.c

+3 −3

Original line number	Diff line number	Diff line
		@@ -7282,10 +7282,10 @@ static inline int find_best_target(struct task_struct p, int backup_cpu,
		!(p->state == TASK_RUNNING && !idle_cpu(most_spare_cap_cpu)))
		target_cpu = most_spare_cap_cpu;

		if (target_cpu == -1 && cpu_isolated(prev_cpu) &&
		isolated_candidate != -1) {
		target_cpu = isolated_candidate;
		if (cpu_isolated(prev_cpu)) {
		fbt_env->avoid_prev_cpu = true;
		if (target_cpu == -1 && isolated_candidate != -1)
		target_cpu = isolated_candidate;
		}

		/*