From: peterz@infradead.org (Peter Zijlstra)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v2 10/11] sched: move cfs task on a CPU with higher capacity
Date: Thu, 29 May 2014 16:04:27 +0200 [thread overview]
Message-ID: <20140529140427.GI11074@laptop.programming.kicks-ass.net> (raw)
In-Reply-To: <1400860385-14555-11-git-send-email-vincent.guittot@linaro.org>
On Fri, May 23, 2014 at 05:53:04PM +0200, Vincent Guittot wrote:
> @@ -7282,6 +7289,12 @@ static inline int nohz_kick_needed(struct rq *rq)
>
> if (nr_busy > 1)
> goto need_kick_unlock;
> +
> + if ((rq->cfs.h_nr_running >= 1)
> + && ((rq->cpu_power * sd->imbalance_pct) <
> + (rq->cpu_power_orig * 100)))
> + goto need_kick_unlock;
> +
> }
>
> sd = rcu_dereference(per_cpu(sd_asym, cpu));
So what happens when a cpu is consistently low on power (say due to a
pinned RT task) the balancer would quickly adjust the load level, but
this would endlessly kick things into action, even though we're balanced
just fine.
WARNING: multiple messages have this Message-ID (diff)
From: Peter Zijlstra <peterz@infradead.org>
To: Vincent Guittot <vincent.guittot@linaro.org>
Cc: mingo@kernel.org, linux-kernel@vger.kernel.org,
linux@arm.linux.org.uk, linux-arm-kernel@lists.infradead.org,
preeti@linux.vnet.ibm.com, Morten.Rasmussen@arm.com,
efault@gmx.de, nicolas.pitre@linaro.org,
linaro-kernel@lists.linaro.org, daniel.lezcano@linaro.org
Subject: Re: [PATCH v2 10/11] sched: move cfs task on a CPU with higher capacity
Date: Thu, 29 May 2014 16:04:27 +0200 [thread overview]
Message-ID: <20140529140427.GI11074@laptop.programming.kicks-ass.net> (raw)
In-Reply-To: <1400860385-14555-11-git-send-email-vincent.guittot@linaro.org>
On Fri, May 23, 2014 at 05:53:04PM +0200, Vincent Guittot wrote:
> @@ -7282,6 +7289,12 @@ static inline int nohz_kick_needed(struct rq *rq)
>
> if (nr_busy > 1)
> goto need_kick_unlock;
> +
> + if ((rq->cfs.h_nr_running >= 1)
> + && ((rq->cpu_power * sd->imbalance_pct) <
> + (rq->cpu_power_orig * 100)))
> + goto need_kick_unlock;
> +
> }
>
> sd = rcu_dereference(per_cpu(sd_asym, cpu));
So what happens when a cpu is consistently low on power (say due to a
pinned RT task) the balancer would quickly adjust the load level, but
this would endlessly kick things into action, even though we're balanced
just fine.
next prev parent reply other threads:[~2014-05-29 14:04 UTC|newest]
Thread overview: 216+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-05-23 15:52 [PATCH v2 00/11] sched: consolidation of cpu_power Vincent Guittot
2014-05-23 15:52 ` Vincent Guittot
2014-05-23 15:52 ` [PATCH v2 01/11] sched: fix imbalance flag reset Vincent Guittot
2014-05-23 15:52 ` Vincent Guittot
2014-05-25 10:33 ` Preeti U Murthy
2014-05-25 10:33 ` Preeti U Murthy
2014-05-26 7:49 ` Vincent Guittot
2014-05-26 7:49 ` Vincent Guittot
2014-05-26 9:16 ` Preeti U Murthy
2014-05-26 9:16 ` Preeti U Murthy
2014-05-26 10:14 ` Vincent Guittot
2014-05-26 10:14 ` Vincent Guittot
2014-05-23 15:52 ` [PATCH v2 02/11] sched: remove a wake_affine condition Vincent Guittot
2014-05-23 15:52 ` Vincent Guittot
2014-05-27 12:48 ` Peter Zijlstra
2014-05-27 12:48 ` Peter Zijlstra
2014-05-27 15:19 ` Vincent Guittot
2014-05-27 15:19 ` Vincent Guittot
2014-05-27 15:39 ` Peter Zijlstra
2014-05-27 15:39 ` Peter Zijlstra
2014-05-27 16:14 ` Vincent Guittot
2014-05-27 16:14 ` Vincent Guittot
2014-05-28 6:49 ` Vincent Guittot
2014-05-28 6:49 ` Vincent Guittot
2014-05-28 15:09 ` Dietmar Eggemann
2014-05-28 15:09 ` Dietmar Eggemann
2014-05-28 15:25 ` Vincent Guittot
2014-05-28 15:25 ` Vincent Guittot
2014-05-27 13:43 ` Peter Zijlstra
2014-05-27 13:43 ` Peter Zijlstra
2014-05-27 13:45 ` Peter Zijlstra
2014-05-27 13:45 ` Peter Zijlstra
2014-05-27 15:20 ` Vincent Guittot
2014-05-27 15:20 ` Vincent Guittot
2014-05-23 15:52 ` [PATCH v2 03/11] sched: fix avg_load computation Vincent Guittot
2014-05-23 15:52 ` Vincent Guittot
2014-05-27 13:48 ` Peter Zijlstra
2014-05-27 13:48 ` Peter Zijlstra
2014-05-23 15:52 ` [PATCH v2 04/11] sched: Allow all archs to set the power_orig Vincent Guittot
2014-05-23 15:52 ` Vincent Guittot
2014-05-30 14:04 ` Dietmar Eggemann
2014-05-30 14:04 ` Dietmar Eggemann
2014-05-30 14:46 ` Peter Zijlstra
2014-05-30 14:46 ` Peter Zijlstra
2014-05-30 20:50 ` Vincent Guittot
2014-05-30 20:50 ` Vincent Guittot
2014-06-04 9:42 ` Dietmar Eggemann
2014-06-04 9:42 ` Dietmar Eggemann
2014-06-04 11:15 ` Vincent Guittot
2014-06-04 11:15 ` Vincent Guittot
2014-06-05 8:59 ` Dietmar Eggemann
2014-06-05 8:59 ` Dietmar Eggemann
2014-06-16 9:01 ` Vincent Guittot
2014-06-16 9:01 ` Vincent Guittot
2014-06-03 13:22 ` Morten Rasmussen
2014-06-03 13:22 ` Morten Rasmussen
2014-06-03 14:02 ` Vincent Guittot
2014-06-03 14:02 ` Vincent Guittot
2014-06-04 11:17 ` Morten Rasmussen
2014-06-04 11:17 ` Morten Rasmussen
2014-06-06 7:01 ` Vincent Guittot
2014-06-06 7:01 ` Vincent Guittot
2014-05-23 15:52 ` [PATCH v2 05/11] ARM: topology: use new cpu_power interface Vincent Guittot
2014-05-23 15:52 ` Vincent Guittot
2014-05-25 13:22 ` Preeti U Murthy
2014-05-25 13:22 ` Preeti U Murthy
2014-05-26 8:25 ` Vincent Guittot
2014-05-26 8:25 ` Vincent Guittot
2014-05-26 9:19 ` Preeti U Murthy
2014-05-26 9:19 ` Preeti U Murthy
2014-05-23 15:53 ` [PATCH v2 06/11] sched: add per rq cpu_power_orig Vincent Guittot
2014-05-23 15:53 ` Vincent Guittot
2014-05-23 15:53 ` [PATCH v2 07/11] Revert "sched: Put rq's sched_avg under CONFIG_FAIR_GROUP_SCHED" Vincent Guittot
2014-05-23 15:53 ` Vincent Guittot
2014-05-23 15:53 ` [PATCH v2 08/11] sched: get CPU's activity statistic Vincent Guittot
2014-05-23 15:53 ` Vincent Guittot
2014-05-27 17:32 ` Peter Zijlstra
2014-05-27 17:32 ` Peter Zijlstra
2014-05-28 7:01 ` Vincent Guittot
2014-05-28 7:01 ` Vincent Guittot
2014-05-28 12:10 ` Morten Rasmussen
2014-05-28 12:10 ` Morten Rasmussen
2014-05-28 13:15 ` Vincent Guittot
2014-05-28 13:15 ` Vincent Guittot
2014-05-28 15:47 ` Morten Rasmussen
2014-05-28 15:47 ` Morten Rasmussen
2014-05-28 16:39 ` Vincent Guittot
2014-05-28 16:39 ` Vincent Guittot
2014-06-03 12:03 ` Morten Rasmussen
2014-06-03 12:03 ` Morten Rasmussen
2014-06-03 15:59 ` Peter Zijlstra
2014-06-03 15:59 ` Peter Zijlstra
2014-06-03 17:41 ` Morten Rasmussen
2014-06-03 17:41 ` Morten Rasmussen
2014-06-03 15:50 ` Peter Zijlstra
2014-06-03 15:50 ` Peter Zijlstra
2014-06-03 17:20 ` Morten Rasmussen
2014-06-03 17:20 ` Morten Rasmussen
2014-06-04 7:47 ` Vincent Guittot
2014-06-04 7:47 ` Vincent Guittot
2014-06-04 8:08 ` Peter Zijlstra
2014-06-04 8:08 ` Peter Zijlstra
2014-06-04 8:55 ` Morten Rasmussen
2014-06-04 8:55 ` Morten Rasmussen
2014-06-04 9:23 ` Peter Zijlstra
2014-06-04 9:23 ` Peter Zijlstra
2014-06-04 9:35 ` Vincent Guittot
2014-06-04 9:35 ` Vincent Guittot
2014-06-04 10:25 ` Morten Rasmussen
2014-06-04 10:25 ` Morten Rasmussen
2014-06-04 9:44 ` Morten Rasmussen
2014-06-04 9:44 ` Morten Rasmussen
2014-06-04 9:32 ` Vincent Guittot
2014-06-04 9:32 ` Vincent Guittot
2014-06-04 10:00 ` Morten Rasmussen
2014-06-04 10:00 ` Morten Rasmussen
2014-06-04 10:17 ` Peter Zijlstra
2014-06-04 10:17 ` Peter Zijlstra
2014-06-04 10:36 ` Morten Rasmussen
2014-06-04 10:36 ` Morten Rasmussen
2014-06-04 10:55 ` Peter Zijlstra
2014-06-04 10:55 ` Peter Zijlstra
2014-06-04 11:07 ` Vincent Guittot
2014-06-04 11:07 ` Vincent Guittot
2014-06-04 11:23 ` Morten Rasmussen
2014-06-04 11:23 ` Morten Rasmussen
2014-06-04 11:52 ` Vincent Guittot
2014-06-04 11:52 ` Vincent Guittot
2014-06-04 13:09 ` Morten Rasmussen
2014-06-04 13:09 ` Morten Rasmussen
2014-06-04 13:23 ` Morten Rasmussen
2014-06-04 13:23 ` Morten Rasmussen
2014-05-28 15:17 ` Peter Zijlstra
2014-05-28 15:17 ` Peter Zijlstra
2014-06-03 15:40 ` Peter Zijlstra
2014-06-03 15:40 ` Peter Zijlstra
2014-06-03 17:16 ` Morten Rasmussen
2014-06-03 17:16 ` Morten Rasmussen
2014-06-03 17:37 ` Peter Zijlstra
2014-06-03 17:37 ` Peter Zijlstra
2014-06-03 17:39 ` Peter Zijlstra
2014-06-03 17:39 ` Peter Zijlstra
2014-06-03 23:11 ` Yuyang Du
2014-06-03 23:11 ` Yuyang Du
2014-05-30 9:50 ` Dietmar Eggemann
2014-05-30 9:50 ` Dietmar Eggemann
2014-05-30 19:20 ` Vincent Guittot
2014-05-30 19:20 ` Vincent Guittot
2014-06-01 11:33 ` Dietmar Eggemann
2014-06-01 11:33 ` Dietmar Eggemann
2014-06-02 14:07 ` Vincent Guittot
2014-06-02 14:07 ` Vincent Guittot
2014-05-23 15:53 ` [PATCH v2 09/11] sched: test the cpu's capacity in wake affine Vincent Guittot
2014-05-23 15:53 ` Vincent Guittot
2014-05-28 10:58 ` Peter Zijlstra
2014-05-28 10:58 ` Peter Zijlstra
2014-05-28 11:15 ` Vincent Guittot
2014-05-28 11:15 ` Vincent Guittot
2014-11-24 0:34 ` Wanpeng Li
2014-11-24 0:34 ` Wanpeng Li
2014-11-24 13:23 ` Vincent Guittot
2014-11-24 13:23 ` Vincent Guittot
2014-05-23 15:53 ` [PATCH v2 10/11] sched: move cfs task on a CPU with higher capacity Vincent Guittot
2014-05-23 15:53 ` Vincent Guittot
2014-05-29 9:50 ` Peter Zijlstra
2014-05-29 9:50 ` Peter Zijlstra
2014-05-29 19:37 ` Vincent Guittot
2014-05-29 19:37 ` Vincent Guittot
2014-05-30 6:29 ` Peter Zijlstra
2014-05-30 6:29 ` Peter Zijlstra
2014-05-30 20:05 ` Vincent Guittot
2014-05-30 20:05 ` Vincent Guittot
2014-06-02 17:06 ` Vincent Guittot
2014-06-02 17:06 ` Vincent Guittot
2014-06-03 11:15 ` Peter Zijlstra
2014-06-03 11:15 ` Peter Zijlstra
2014-06-03 12:31 ` Vincent Guittot
2014-06-03 12:31 ` Vincent Guittot
2014-05-29 14:04 ` Peter Zijlstra [this message]
2014-05-29 14:04 ` Peter Zijlstra
2014-05-29 19:44 ` Vincent Guittot
2014-05-29 19:44 ` Vincent Guittot
2014-05-30 13:26 ` Dietmar Eggemann
2014-05-30 13:26 ` Dietmar Eggemann
2014-05-30 19:24 ` Vincent Guittot
2014-05-30 19:24 ` Vincent Guittot
2014-05-30 19:45 ` Nicolas Pitre
2014-05-30 19:45 ` Nicolas Pitre
2014-05-30 20:07 ` Vincent Guittot
2014-05-30 20:07 ` Vincent Guittot
2014-05-23 15:53 ` [PATCH v2 11/11] sched: replace capacity by activity Vincent Guittot
2014-05-23 15:53 ` Vincent Guittot
2014-05-29 13:55 ` Peter Zijlstra
2014-05-29 13:55 ` Peter Zijlstra
2014-05-29 19:51 ` Vincent Guittot
2014-05-29 19:51 ` Vincent Guittot
2014-06-02 6:21 ` Preeti U Murthy
2014-06-02 6:21 ` Preeti U Murthy
2014-06-03 9:50 ` Vincent Guittot
2014-06-03 9:50 ` Vincent Guittot
2014-05-29 14:02 ` Peter Zijlstra
2014-05-29 14:02 ` Peter Zijlstra
2014-05-29 19:56 ` Vincent Guittot
2014-05-29 19:56 ` Vincent Guittot
2014-05-30 6:34 ` Peter Zijlstra
2014-05-30 6:34 ` Peter Zijlstra
2014-05-30 19:13 ` Vincent Guittot
2014-05-30 19:13 ` Vincent Guittot
2014-05-26 9:44 ` [PATCH v2 00/11] sched: consolidation of cpu_power Preeti U Murthy
2014-05-26 9:44 ` Preeti U Murthy
2014-05-26 10:04 ` Vincent Guittot
2014-05-26 10:04 ` Vincent Guittot
2014-05-26 15:54 ` Vincent Guittot
2014-05-26 15:54 ` Vincent Guittot
2014-05-27 5:47 ` Preeti U Murthy
2014-05-27 5:47 ` Preeti U Murthy
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