From: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
To: Ingo Molnar <mingo@kernel.org>, Peter Zijlstra <peterz@infradead.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
Mel Gorman <mgorman@techsingularity.net>,
Rik van Riel <riel@surriel.com>,
Srikar Dronamraju <srikar@linux.vnet.ibm.com>,
Thomas Gleixner <tglx@linutronix.de>,
Valentin Schneider <valentin.schneider@arm.com>,
Vincent Guittot <vincent.guittot@linaro.org>,
Dietmar Eggemann <dietmar.eggemann@arm.com>,
Gautham R Shenoy <ego@linux.vnet.ibm.com>,
Parth Shah <parth@linux.ibm.com>,
Aubrey Li <aubrey.li@linux.intel.com>
Subject: [PATCH v3 1/8] sched/fair: Update affine statistics when needed
Date: Thu, 13 May 2021 13:10:20 +0530 [thread overview]
Message-ID: <20210513074027.543926-2-srikar@linux.vnet.ibm.com> (raw)
In-Reply-To: <20210513074027.543926-1-srikar@linux.vnet.ibm.com>
wake_affine_idle() can return prev_cpu. Even in such a scenario,
scheduler was going ahead and updating schedstats related to wake
affine. i.e even if the task is not moved to current CPU,
schedstats would have accounted.
Hence add a check before updating schedstats.
Cc: LKML <linux-kernel@vger.kernel.org>
Cc: Gautham R Shenoy <ego@linux.vnet.ibm.com>
Cc: Parth Shah <parth@linux.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Valentin Schneider <valentin.schneider@arm.com>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Aubrey Li <aubrey.li@linux.intel.com>
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
---
Changelog v2-v3:
- Update schedstat if target is current CPU
(Valentin)
kernel/sched/fair.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 1d75af1ecfb4..7920f2a4d257 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -5908,8 +5908,10 @@ static int wake_affine(struct sched_domain *sd, struct task_struct *p,
if (target == nr_cpumask_bits)
return prev_cpu;
- schedstat_inc(sd->ttwu_move_affine);
- schedstat_inc(p->se.statistics.nr_wakeups_affine);
+ if (target == this_cpu) {
+ schedstat_inc(sd->ttwu_move_affine);
+ schedstat_inc(p->se.statistics.nr_wakeups_affine);
+ }
return target;
}
--
2.18.2
next prev parent reply other threads:[~2021-05-13 7:41 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-13 7:40 [PATCH v3 0/8] sched/fair: wake_affine improvements Srikar Dronamraju
2021-05-13 7:40 ` Srikar Dronamraju [this message]
2021-05-13 7:40 ` [PATCH v3 2/8] sched/fair: Maintain the identity of idle-core Srikar Dronamraju
2021-05-21 12:36 ` Vincent Guittot
2021-05-21 13:31 ` Srikar Dronamraju
2021-05-22 12:42 ` Vincent Guittot
2021-05-22 14:10 ` Srikar Dronamraju
2021-05-25 7:11 ` Vincent Guittot
2021-05-13 7:40 ` [PATCH v3 3/8] sched/fair: Update idle-core more often Srikar Dronamraju
2021-05-13 7:40 ` [PATCH v3 4/8] sched/fair: Prefer idle CPU to cache affinity Srikar Dronamraju
2021-05-13 7:40 ` [PATCH v3 5/8] sched/fair: Use affine_idler_llc for wakeups across LLC Srikar Dronamraju
2021-05-13 7:40 ` [PATCH v3 6/8] sched/idle: Move busy_cpu accounting to idle callback Srikar Dronamraju
2021-05-21 12:37 ` Vincent Guittot
2021-05-21 13:21 ` Srikar Dronamraju
2021-05-13 7:40 ` [PATCH v3 7/8] sched/fair: Remove ifdefs in waker_affine_idler_llc Srikar Dronamraju
2021-05-13 7:40 ` [PATCH v3 8/8] sched/fair: Dont iterate if no idle CPUs Srikar Dronamraju
2021-05-19 9:36 ` [PATCH v3 0/8] sched/fair: wake_affine improvements Mel Gorman
2021-05-19 16:55 ` Srikar Dronamraju
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