[PATCH 5.3 030/105] sched/pelt: Fix update of blocked PELT ordering

Greg Kroah-Hartman
2019-12-11T15:12:34Z

From: Vincent Guittot <vincent.guittot@linaro.org>

[ Upstream commit b90f7c9d2198d789709390280a43e0a46345682b ]

update_cfs_rq_load_avg() can call cpufreq_update_util() to trigger an
update of the frequency. Make sure that RT, DL and IRQ PELT signals have
been updated before calling cpufreq.

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: dietmar.eggemann@arm.com
Cc: dsmythies@telus.net
Cc: juri.lelli@redhat.com
Cc: mgorman@suse.de
Cc: rostedt@goodmis.org
Fixes: 371bf4273269 ("sched/rt: Add rt_rq utilization tracking")
Fixes: 3727e0e16340 ("sched/dl: Add dl_rq utilization tracking")
Fixes: 91c27493e78d ("sched/irq: Add IRQ utilization tracking")
Link: https://lkml.kernel.org/r/1572434309-32512-1-git-send-email-vincent.guittot@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
kernel/sched/fair.c | 29 ++++++++++++++++++++---------
1 file changed, 20 insertions(+), 9 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 649c6b60929e2..ba7cc68a39935 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -7530,6 +7530,19 @@ static void update_blocked_averages(int cpu)
rq_lock_irqsave(rq, &rf);
update_rq_clock(rq);

+ /*
+ * update_cfs_rq_load_avg() can call cpufreq_update_util(). Make sure
+ * that RT, DL and IRQ signals have been updated before updating CFS.
+ */
+ curr_class = rq->curr->sched_class;
+ update_rt_rq_load_avg(rq_clock_pelt(rq), rq, curr_class == &rt_sched_class);
+ update_dl_rq_load_avg(rq_clock_pelt(rq), rq, curr_class == &dl_sched_class);
+ update_irq_load_avg(rq, 0);
+
+ /* Don't need periodic decay once load/util_avg are null */
+ if (others_have_blocked(rq))
+ done = false;
+
/*
* Iterates the task_group tree in a bottom up fashion, see
* list_add_leaf_cfs_rq() for details.
@@ -7557,14 +7570,6 @@ static void update_blocked_averages(int cpu)
done = false;
}

- curr_class = rq->curr->sched_class;
- update_rt_rq_load_avg(rq_clock_pelt(rq), rq, curr_class == &rt_sched_class);
- update_dl_rq_load_avg(rq_clock_pelt(rq), rq, curr_class == &dl_sched_class);
- update_irq_load_avg(rq, 0);
- /* Don't need periodic decay once load/util_avg are null */
- if (others_have_blocked(rq))
- done = false;
-
update_blocked_load_status(rq, !done);
rq_unlock_irqrestore(rq, &rf);
}
@@ -7625,12 +7630,18 @@ static inline void update_blocked_averages(int cpu)

rq_lock_irqsave(rq, &rf);
update_rq_clock(rq);
- update_cfs_rq_load_avg(cfs_rq_clock_pelt(cfs_rq), cfs_rq);

+ /*
+ * update_cfs_rq_load_avg() can call cpufreq_update_util(). Make sure
+ * that RT, DL and IRQ signals have been updated before updating CFS.
+ */
curr_class = rq->curr->sched_class;
update_rt_rq_load_avg(rq_clock_pelt(rq), rq, curr_class == &rt_sched_class);
update_dl_rq_load_avg(rq_clock_pelt(rq), rq, curr_class == &dl_sched_class);
update_irq_load_avg(rq, 0);
+
+ update_cfs_rq_load_avg(cfs_rq_clock_pelt(cfs_rq), cfs_rq);
+
update_blocked_load_status(rq, cfs_rq_has_blocked(cfs_rq) || others_have_blocked(rq));
rq_unlock_irqrestore(rq, &rf);
}
--
2.20.1