[Eas-dev] [PATCH RFCv3 12/18] sched/fair: refine when task is allowed only run one CPU

Add check if task is only permitted to run on one CPU. So it will directly return back when task is waken up.

Signed-off-by: Leo Yan leo.yan@linaro.org --- kernel/sched/fair.c | 3 +++ 1 file changed, 3 insertions(+)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index ac4f509..9ac593b 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -5966,6 +5966,9 @@ select_task_rq_fair(struct task_struct *p, int prev_cpu, int sd_flag, int wake_f int want_affine = 0; int sync = wake_flags & WF_SYNC;

+ if (p->nr_cpus_allowed == 1) + return prev_cpu; + if (sd_flag & SD_BALANCE_WAKE) want_affine = (!wake_wide(p) && task_fits_max(p, cpu) && cpumask_test_cpu(cpu, tsk_cpus_allowed(p))) || -- 1.9.1