@@ -1177,6 +1177,7 @@ static int find_later_rq(struct task_struct *task)
struct cpumask *later_mask = this_cpu_cpumask_var_ptr(local_cpu_mask_dl);
int this_cpu = smp_processor_id();
int cpu = task_cpu(task);
+ int cachehot_cpu = nr_cpu_ids;
/* Make sure the mask is initialized first */
if (unlikely(!later_mask))
@@ -1219,7 +1220,7 @@ static int find_later_rq(struct task_struct *task)
rcu_read_lock();
for_each_domain(cpu, sd) {
- int best_cpu;
+ int wakeaffine_cpu;
if (sd->flags & SD_WAKE_AFFINE) {
/*
@@ -1232,16 +1233,24 @@ static int find_later_rq(struct task_struct *task)
return this_cpu;
}
- best_cpu = cpumask_first_and(later_mask,
- sched_domain_span(sd));
- if (best_cpu < nr_cpu_ids) {
+ wakeaffine_cpu = cpumask_first_and(later_mask,
+ sched_domain_span(sd));
+ if (wakeaffine_cpu < nr_cpu_ids) {
rcu_read_unlock();
- return best_cpu;
+ return wakeaffine_cpu;
}
+ } else {
+ if (cachehot_cpu >= nr_cpu_ids)
+ cachehot_cpu = cpumask_first_and(later_mask,
+ sched_domain_span(sd));
}
}
rcu_read_unlock();
+ /* Most likely cache-hot */
+ if (cachehot_cpu < nr_cpu_ids)
+ return cachehot_cpu;
+
/*
* At this point, all our guesses failed, we just return
* 'something', and let the caller sort the things out.
Add the case for iteration of sched_domains without SD_WAKE_AFFINE flags to select a cpu, this flag may be unset through proc by users. Signed-off-by: pang.xunlei <pang.xunlei@linaro.org> --- kernel/sched/deadline.c | 19 ++++++++++++++----- 1 file changed, 14 insertions(+), 5 deletions(-)