From: Vincent Guittot <vincent.guittot@linaro.org>
To: mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com,
dietmar.eggemann@arm.com, rostedt@goodmis.org,
bsegall@google.com, mgorman@suse.de, bristot@redhat.com,
linux-kernel@vger.kernel.org
Cc: odin@uged.al, Vincent Guittot <vincent.guittot@linaro.org>
Subject: [PATCH] sched/pelt: check that *_avg are null when *_sum are
Date: Tue, 1 Jun 2021 17:53:28 +0200 [thread overview]
Message-ID: <20210601155328.19487-1-vincent.guittot@linaro.org> (raw)
Check that we never break the rule that pelt's avg values are null if
pelt's sum are.
Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
---
This is what I used for patch 20210601085832.12626-1-vincent.guittot@linaro.org
kernel/sched/fair.c | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index a2c30e52de76..c17feadeafcc 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -8021,6 +8021,15 @@ static inline bool cfs_rq_is_decayed(struct cfs_rq *cfs_rq)
if (cfs_rq->avg.runnable_sum)
return false;
+ /*
+ * _avg must be null when _sum are null because _avg = _sum / divider
+ * Make sure that rounding and/or propagation of PELT values never
+ * break this.
+ */
+ SCHED_WARN_ON(cfs_rq->avg.load_avg ||
+ cfs_rq->avg.util_avg ||
+ cfs_rq->avg.runnable_avg);
+
return true;
}
--
2.17.1
next reply other threads:[~2021-06-01 15:53 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-01 15:53 Vincent Guittot [this message]
2021-06-02 6:45 ` [sched/pelt] e906550aca: WARNING:at_kernel/sched/fair.c:#update_blocked_averages kernel test robot
2021-06-03 10:50 ` Dietmar Eggemann
2021-06-03 10:59 ` Vincent Guittot
2021-06-03 10:42 ` [PATCH] sched/pelt: check that *_avg are null when *_sum are Dietmar Eggemann
2021-06-03 11:06 ` Odin Ugedal
2021-06-03 12:47 ` Vincent Guittot
2021-06-03 14:32 ` Odin Ugedal
2021-06-18 8:46 ` [tip: sched/core] sched/pelt: Check " tip-bot2 for Vincent Guittot
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