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.xun...@linaro.org>
---
 kernel/sched/deadline.c |   19 ++++++++++++++-----
 1 file changed, 14 insertions(+), 5 deletions(-)

diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
index e0e8013..01d3aaab 100644
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
@@ -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.
-- 
1.7.9.5

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to