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>
Subject: [PATCH 01/10] sched/fair: Update affine statistics when needed
Date: Thu, 22 Apr 2021 15:53:17 +0530 [thread overview]
Message-ID: <20210422102326.35889-2-srikar@linux.vnet.ibm.com> (raw)
In-Reply-To: <20210422102326.35889-1-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 across LLC domains,
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>
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
---
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 794c2cb945f8..a258a84cfdfd 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -5884,8 +5884,10 @@ 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 (!cpus_share_cache(prev_cpu, target)) {
+ 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:[~2021-04-22 10:24 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-22 10:23 [PATCH 00/10] sched/fair: wake_affine improvements Srikar Dronamraju
2021-04-22 10:23 ` Srikar Dronamraju [this message]
2021-04-22 10:23 ` [PATCH 02/10] sched/fair: Maintain the identity of idle-core Srikar Dronamraju
2021-04-22 10:23 ` [PATCH 03/10] sched/fair: Update idle-core more often Srikar Dronamraju
2021-04-22 10:23 ` [PATCH 04/10] sched/fair: Prefer idle CPU to cache affinity Srikar Dronamraju
2021-04-22 10:23 ` [PATCH 05/10] sched/fair: Call wake_affine only if necessary Srikar Dronamraju
2021-04-22 10:23 ` [PATCH 06/10] sched/idle: Move busy_cpu accounting to idle callback Srikar Dronamraju
2021-04-22 10:23 ` [PATCH 07/10] sched/fair: Remove ifdefs in waker_affine_idler_llc Srikar Dronamraju
2021-04-22 10:23 ` [PATCH 08/10] sched/fair: Dont iterate if no idle CPUs Srikar Dronamraju
2021-04-22 10:23 ` [PATCH 09/10] sched/topology: Introduce fallback LLC Srikar Dronamraju
2021-04-22 15:10 ` kernel test robot
2021-04-22 10:23 ` [PATCH 10/10] powerpc/smp: Add fallback flag to powerpc MC domain Srikar Dronamraju
2021-04-23 8:25 ` [PATCH 00/10] sched/fair: wake_affine improvements Mel Gorman
2021-04-23 10:31 ` Srikar Dronamraju
2021-04-23 12:38 ` Mel Gorman
2021-04-26 10:30 ` Srikar Dronamraju
2021-04-26 11:35 ` Mel Gorman
2021-04-26 10:39 ` Srikar Dronamraju
2021-04-26 11:41 ` Mel Gorman
2021-04-28 12:57 ` Srikar Dronamraju
2021-04-27 14:52 ` Vincent Guittot
2021-04-28 12:49 ` Srikar Dronamraju
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