From: Alex Shi <alex.shi@intel.com>
To: mingo@redhat.com, peterz@infradead.org, tglx@linutronix.de,
akpm@linux-foundation.org, arjan@linux.intel.com, bp@alien8.de,
pjt@google.com, namhyung@kernel.org, efault@gmx.de,
morten.rasmussen@arm.com
Cc: vincent.guittot@linaro.org, gregkh@linuxfoundation.org,
preeti@linux.vnet.ibm.com, viresh.kumar@linaro.org,
linux-kernel@vger.kernel.org, alex.shi@intel.com,
len.brown@intel.com, rafael.j.wysocki@intel.com, jkosina@suse.cz,
clark.williams@gmail.com, tony.luck@intel.com,
keescook@chromium.org, mgorman@suse.de, riel@redhat.com
Subject: [Resend patch v8 04/13] sched: fix slept time double counting in enqueue entity
Date: Thu, 20 Jun 2013 10:18:48 +0800 [thread overview]
Message-ID: <1371694737-29336-5-git-send-email-alex.shi@intel.com> (raw)
In-Reply-To: <1371694737-29336-1-git-send-email-alex.shi@intel.com>
The wakeuped migrated task will __synchronize_entity_decay(se); in
migrate_task_rq_fair, then it needs to set
`se->avg.last_runnable_update -= (-se->avg.decay_count) << 20'
before update_entity_load_avg, in order to avoid slept time is updated
twice for se.avg.load_avg_contrib in both __syncchronize and
update_entity_load_avg.
but if the slept task is waked up from self cpu, it miss the
last_runnable_update before update_entity_load_avg(se, 0, 1), then the
slept time was used twice in both functions.
So we need to remove the double slept time counting.
Paul also contribute some code comments in this commit.
Signed-off-by: Alex Shi <alex.shi@intel.com>
Reviewed-by: Paul Turner <pjt@google.com>
---
kernel/sched/fair.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index df5b8a9..1e5a5e6 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -1571,7 +1571,13 @@ static inline void enqueue_entity_load_avg(struct cfs_rq *cfs_rq,
}
wakeup = 0;
} else {
- __synchronize_entity_decay(se);
+ /*
+ * Task re-woke on same cpu (or else migrate_task_rq_fair()
+ * would have made count negative); we must be careful to avoid
+ * double-accounting blocked time after synchronizing decays.
+ */
+ se->avg.last_runnable_update += __synchronize_entity_decay(se)
+ << 20;
}
/* migrated tasks did not contribute to our blocked load */
--
1.7.12
next prev parent reply other threads:[~2013-06-20 2:21 UTC|newest]
Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-06-20 2:18 [Resend patch v8 0/13] use runnable load in schedule balance Alex Shi
2013-06-20 2:18 ` [Resend patch v8 01/13] Revert "sched: Introduce temporary FAIR_GROUP_SCHED dependency for load-tracking" Alex Shi
2013-06-26 5:05 ` Alex Shi
2013-06-26 20:30 ` Ingo Molnar
2013-06-27 1:07 ` Alex Shi
2013-06-27 9:01 ` [tip:sched/core] " tip-bot for Alex Shi
2013-06-20 2:18 ` [Resend patch v8 02/13] sched: move few runnable tg variables into CONFIG_SMP Alex Shi
2013-06-27 9:01 ` [tip:sched/core] sched: Move a " tip-bot for Alex Shi
2013-06-20 2:18 ` [Resend patch v8 03/13] sched: set initial value of runnable avg for new forked task Alex Shi
2013-06-27 9:01 ` [tip:sched/core] sched: Set an " tip-bot for Alex Shi
2013-06-20 2:18 ` Alex Shi [this message]
2013-06-27 9:01 ` [tip:sched/core] sched: Fix sleep time double accounting in enqueue entity tip-bot for Alex Shi
2013-06-20 2:18 ` [Resend patch v8 05/13] sched: update cpu load after task_tick Alex Shi
2013-06-27 9:02 ` [tip:sched/core] sched: Update " tip-bot for Alex Shi
2013-06-20 2:18 ` [Resend patch v8 06/13] sched: compute runnable load avg in cpu_load and cpu_avg_load_per_task Alex Shi
2013-06-20 13:29 ` Vincent Guittot
2013-06-24 9:06 ` Alex Shi
2013-06-24 10:54 ` Paul Turner
2013-06-24 11:04 ` Vincent Guittot
2013-06-24 11:06 ` Paul Turner
2013-06-24 14:56 ` Alex Shi
2013-06-27 9:02 ` [tip:sched/core] sched: Compute " tip-bot for Alex Shi
2013-06-27 13:30 ` [Resend patch v8 06/13] sched: compute " Alex Shi
2013-06-20 2:18 ` [Resend patch v8 07/13] sched: consider runnable load average in move_tasks Alex Shi
2013-06-27 9:02 ` [tip:sched/core] sched: Consider runnable load average in move_tasks() tip-bot for Alex Shi
2013-06-20 2:18 ` [Resend patch v8 08/13] sched/tg: remove blocked_load_avg in balance Alex Shi
2013-06-20 2:18 ` [Resend patch v8 09/13] sched: change cfs_rq load avg to unsigned long Alex Shi
2013-06-27 9:02 ` [tip:sched/core] sched: Change " tip-bot for Alex Shi
2013-06-20 2:18 ` [Resend patch v8 10/13] sched/tg: use 'unsigned long' for load variable in task group Alex Shi
2013-06-27 9:02 ` [tip:sched/core] sched/tg: Use " tip-bot for Alex Shi
2013-06-20 2:18 ` [Resend patch v8 11/13] sched/cfs_rq: change atomic64_t removed_load to atomic_long_t Alex Shi
2013-06-27 9:02 ` [tip:sched/core] sched/cfs_rq: Change " tip-bot for Alex Shi
2013-06-20 2:18 ` [Resend patch v8 12/13] sched/tg: remove tg.load_weight Alex Shi
2013-06-27 9:02 ` [tip:sched/core] sched/tg: Remove tg.load_weight tip-bot for Alex Shi
2013-06-20 2:18 ` [Resend patch v8 13/13] sched: get_rq_runnable_load() can be static and inline Alex Shi
2013-06-27 9:03 ` [tip:sched/core] sched: Change get_rq_runnable_load() to " tip-bot for Alex Shi
2013-06-24 3:15 ` [Resend patch v8 0/13] use runnable load in schedule balance Alex Shi
2013-06-24 10:40 ` Paul Turner
2013-06-24 15:37 ` Alex Shi
2013-06-25 13:13 ` Alex Shi
2013-06-28 10:56 ` Paul Turner
2013-06-28 11:07 ` Peter Zijlstra
2013-06-28 11:12 ` Alex Shi
2013-10-28 10:25 ` Frederic Weisbecker
2013-10-28 12:22 ` Peter Zijlstra
[not found] ` <CAGjg+kGUo8vqv6hzobuyNoQjipLBXXofZ5q1rUyEehbD3cba9A@mail.gmail.com>
2013-06-28 16:00 ` Paul Turner
2013-07-09 8:53 ` Alex Shi
2013-06-26 14:27 ` Peter Zijlstra
2013-06-26 15:23 ` Alex Shi
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