diff options
| author | Patrick Bellasi <patrick.bellasi@arm.com> | 2017-09-07 12:27:56 +0100 |
|---|---|---|
| committer | Chris Redpath <chris.redpath@arm.com> | 2017-10-27 13:30:33 +0100 |
| commit | 4edc5b0e387a906a00cb45af2abf76aa3a930438 (patch) | |
| tree | 34dd5ab1860ae89999f7351c36332f2d6c15c1b4 /kernel/sched | |
| parent | 2aada289d7be37116f21d70177cb06a929b5d961 (diff) | |
sched/fair: ignore backup CPU when not valid
The find_best_target can sometimes not return a valid backup CPU, either
because it cannot find one or just becasue it returns prev_cpu as a backup.
In these cases we should skip the energy_diff evaluation for the backup CPU.
Change-Id: I3787dbdfe74122348dd7a7485b88c4679051bd32
Signed-off-by: Patrick Bellasi <patrick.bellasi@arm.com>
Signed-off-by: Chris Redpath <chris.redpath@arm.com>
Diffstat (limited to 'kernel/sched')
| -rw-r--r-- | kernel/sched/fair.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index a17820385ee2..417b373e4074 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -6686,7 +6686,9 @@ static int select_energy_cpu_brute(struct task_struct *p, int prev_cpu, int sync /* No energy saving for target_cpu, try backup */ target_cpu = tmp_backup; eenv.dst_cpu = target_cpu; - if (tmp_backup < 0 || energy_diff(&eenv) >= 0) { + if (tmp_backup < 0 || + tmp_backup == prev_cpu || + energy_diff(&eenv) >= 0) { schedstat_inc(p, se.statistics.nr_wakeups_secb_no_nrg_sav); schedstat_inc(this_rq(), eas_stats.secb_no_nrg_sav); target_cpu = prev_cpu; |