From: tip-bot for Vincent Guittot <tipbot@zytor.com>
To: linux-tip-commits@vger.kernel.org
Cc: linux-kernel@vger.kernel.org, tglx@linutronix.de,
peterz@infradead.org, torvalds@linux-foundation.org,
mingo@kernel.org, hpa@zytor.com, vincent.guittot@linaro.org
Subject: [tip:sched/core] sched/fair: Reduce the periodic update duration
Date: Fri, 9 Mar 2018 01:04:09 -0800 [thread overview]
Message-ID: <tip-1936c53ce8c8d4555e9ccad2dc8d98e0637b11f7@git.kernel.org> (raw)
In-Reply-To: <1518517879-2280-3-git-send-email-vincent.guittot@linaro.org>
Commit-ID: 1936c53ce8c8d4555e9ccad2dc8d98e0637b11f7
Gitweb: https://git.kernel.org/tip/1936c53ce8c8d4555e9ccad2dc8d98e0637b11f7
Author: Vincent Guittot <vincent.guittot@linaro.org>
AuthorDate: Tue, 13 Feb 2018 11:31:18 +0100
Committer: Ingo Molnar <mingo@kernel.org>
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@linaro.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: brendan.jackman@arm.com
Cc: dietmar.eggemann@arm.com
Cc: morten.rasmussen@foss.arm.com
Cc: valentin.schneider@arm.com
Link: http://lkml.kernel.org/r/1518517879-2280-3-git-send-email-vincent.guittot@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
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);
next prev parent reply other threads:[~2018-03-09 9:04 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-02-13 10:31 [PATCH v4 0/3] sched: Update blocked load Vincent Guittot
2018-02-13 10:31 ` [PATCH v4 1/3] sched: Stop nohz stats when decayed Vincent Guittot
2018-03-09 9:03 ` [tip:sched/core] sched/nohz: Stop NOHZ " tip-bot for Vincent Guittot
2018-02-13 10:31 ` [PATCH v4 2/3] sched: reduce the periodic update duration Vincent Guittot
2018-03-09 9:04 ` tip-bot for Vincent Guittot [this message]
2018-02-13 10:31 ` [PATCH 3/3] sched: update blocked load when newly idle Vincent Guittot
2018-02-14 14:40 ` Valentin Schneider
2018-02-14 14:43 ` Vincent Guittot
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