Commit-ID: 1936c53ce8c8d4555e9ccad2dc8d98e0637b11f7
Gitweb: https://git.kernel.org/tip/1936c53ce8c8d4555e9ccad2dc8d98e0637b11f7
Author: Vincent Guittot <vincent.guittot@xxxxxxxxxx>
AuthorDate: Tue, 13 Feb 2018 11:31:18 +0100
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Fri, 9 Mar 2018 07:59:22 +0100
sched/fair: Reduce the periodic update duration
Instead of using the cfs_rq_is_decayed() which monitors all *_avg
and *_sum, we create a cfs_rq_has_blocked() which only takes care of
util_avg and load_avg. We are only interested by these 2 values which are
decaying faster than the *_sum so we can stop the periodic update earlier.
Signed-off-by: Vincent Guittot <vincent.guittot@xxxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: brendan.jackman@xxxxxxx
Cc: dietmar.eggemann@xxxxxxx
Cc: morten.rasmussen@xxxxxxxxxxxx
Cc: valentin.schneider@xxxxxxx
Link: http://lkml.kernel.org/r/1518517879-2280-3-git-send-email-vincent.guittot@xxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
kernel/sched/fair.c | 21 +++++++++++++++++----
1 file changed, 17 insertions(+), 4 deletions(-)
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 78b06a0814d1..aad7c03dbad8 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -7424,6 +7424,19 @@ static void attach_tasks(struct lb_env *env)
rq_unlock(env->dst_rq, &rf);
}
+static inline bool cfs_rq_has_blocked(struct cfs_rq *cfs_rq)
+{
+ if (cfs_rq->avg.load_avg)
+ return true;
+
+ if (cfs_rq->avg.util_avg)
+ return true;
+
+ return false;
+}
+
+#ifdef CONFIG_FAIR_GROUP_SCHED
+
static inline bool cfs_rq_is_decayed(struct cfs_rq *cfs_rq)
{
if (cfs_rq->load.weight)
@@ -7441,8 +7454,6 @@ static inline bool cfs_rq_is_decayed(struct cfs_rq *cfs_rq)
return true;
}
-#ifdef CONFIG_FAIR_GROUP_SCHED
-
static void update_blocked_averages(int cpu)
{
struct rq *rq = cpu_rq(cpu);
@@ -7478,7 +7489,9 @@ static void update_blocked_averages(int cpu)
*/
if (cfs_rq_is_decayed(cfs_rq))
list_del_leaf_cfs_rq(cfs_rq);
- else
+
+ /* Don't need periodic decay once load/util_avg are null */
+ if (cfs_rq_has_blocked(cfs_rq))
done = false;
}
@@ -7548,7 +7561,7 @@ static inline void update_blocked_averages(int cpu)
update_cfs_rq_load_avg(cfs_rq_clock_task(cfs_rq), cfs_rq);
#ifdef CONFIG_NO_HZ_COMMON
rq->last_blocked_load_update_tick = jiffies;
- if (cfs_rq_is_decayed(cfs_rq))
+ if (!cfs_rq_has_blocked(cfs_rq))
rq->has_blocked_load = 0;
#endif
rq_unlock_irqrestore(rq, &rf);
--
To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
|