From: Preeti U Murthy <preeti@linux.vnet.ibm.com>
To: Alex Shi <alex.shi@intel.com>
Cc: mingo@redhat.com, peterz@infradead.org, efault@gmx.de,
torvalds@linux-foundation.org, tglx@linutronix.de,
akpm@linux-foundation.org, arjan@linux.intel.com, bp@alien8.de,
pjt@google.com, namhyung@kernel.org, vincent.guittot@linaro.org,
gregkh@linuxfoundation.org, viresh.kumar@linaro.org,
linux-kernel@vger.kernel.org, morten.rasmussen@arm.com
Subject: Re: [patch v5 14/15] sched: power aware load balance
Date: Thu, 21 Mar 2013 15:57:06 +0530 [thread overview]
Message-ID: <514AE07A.10100@linux.vnet.ibm.com> (raw)
In-Reply-To: <514AD26F.9010905@intel.com>
On 03/21/2013 02:57 PM, Alex Shi wrote:
> On 03/21/2013 04:41 PM, Preeti U Murthy wrote:
>>>>
>> Yes, I did find this behaviour on a 2 socket, 8 core machine very
>> consistently.
>>
>> rq->util cannot go to 0, after it has begun accumulating load right?
>>
>> Say a load was running on a runqueue which had its rq->util to be at
>> 100%. After the load finishes, the runqueue goes idle. For every
>> scheduler tick, its utilisation decays. But can never become 0.
>>
>> rq->util = rq->avg.runnable_avg_sum/rq->avg.runnable_avg_period
>
>
> did you close all of background system services?
> In theory the rq->avg.runnable_avg_sum should be zero if there is no
> task a bit long, otherwise there are some bugs in kernel.
Could you explain why rq->avg.runnable_avg_sum should be zero? What if
some kernel thread ran on this run queue and is now finished? Its
utilisation would be say x.How would that ever drop to 0,even if nothing
ran on it later?
Regards
Preeti U Murthy
Could you
> check the value under /proc/sched_debug?
>
>
next prev parent reply other threads:[~2013-03-21 10:28 UTC|newest]
Thread overview: 90+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-02-18 5:07 [patch v5 0/15] power aware scheduling Alex Shi
2013-02-18 5:07 ` [patch v5 01/15] sched: set initial value for runnable avg of sched entities Alex Shi
2013-02-18 8:28 ` Joonsoo Kim
2013-02-18 9:16 ` Alex Shi
2013-02-18 5:07 ` [patch v5 02/15] sched: set initial load avg of new forked task Alex Shi
2013-02-20 6:20 ` Alex Shi
2013-02-24 10:57 ` Preeti U Murthy
2013-02-25 6:00 ` Alex Shi
2013-02-28 7:03 ` Preeti U Murthy
2013-02-25 7:12 ` Alex Shi
2013-02-18 5:07 ` [patch v5 03/15] Revert "sched: Introduce temporary FAIR_GROUP_SCHED dependency for load-tracking" Alex Shi
2013-02-18 5:07 ` [patch v5 04/15] sched: add sched balance policies in kernel Alex Shi
2013-02-20 9:37 ` Ingo Molnar
2013-02-20 13:40 ` Alex Shi
2013-02-20 15:41 ` Ingo Molnar
2013-02-21 1:43 ` Alex Shi
2013-02-18 5:07 ` [patch v5 05/15] sched: add sysfs interface for sched_balance_policy selection Alex Shi
2013-02-18 5:07 ` [patch v5 06/15] sched: log the cpu utilization at rq Alex Shi
2013-02-20 9:30 ` Peter Zijlstra
2013-02-20 12:09 ` Preeti U Murthy
2013-02-20 13:34 ` Peter Zijlstra
2013-02-20 14:36 ` Alex Shi
2013-02-20 14:33 ` Alex Shi
2013-02-20 15:20 ` Peter Zijlstra
2013-02-21 1:35 ` Alex Shi
2013-02-20 15:22 ` Peter Zijlstra
2013-02-25 2:26 ` Alex Shi
2013-03-22 8:49 ` Alex Shi
2013-02-20 12:19 ` Preeti U Murthy
2013-02-20 12:39 ` Alex Shi
2013-02-18 5:07 ` [patch v5 07/15] sched: add new sg/sd_lb_stats fields for incoming fork/exec/wake balancing Alex Shi
2013-02-20 9:38 ` Peter Zijlstra
2013-02-20 12:27 ` Alex Shi
2013-02-18 5:07 ` [patch v5 08/15] sched: move sg/sd_lb_stats struct ahead Alex Shi
2013-02-18 5:07 ` [patch v5 09/15] sched: add power aware scheduling in fork/exec/wake Alex Shi
2013-02-20 9:42 ` Peter Zijlstra
2013-02-20 12:09 ` Alex Shi
2013-02-20 13:36 ` Peter Zijlstra
2013-02-20 14:23 ` Alex Shi
2013-02-21 13:33 ` Peter Zijlstra
2013-02-21 14:40 ` Alex Shi
2013-02-22 8:54 ` Peter Zijlstra
2013-02-24 9:27 ` Alex Shi
2013-02-24 9:49 ` Preeti U Murthy
2013-02-24 11:55 ` Alex Shi
2013-02-24 17:51 ` Preeti U Murthy
2013-02-25 2:23 ` Alex Shi
2013-02-25 3:23 ` Mike Galbraith
2013-02-25 9:53 ` Alex Shi
2013-02-25 10:30 ` Mike Galbraith
2013-02-18 5:07 ` [patch v5 10/15] sched: packing transitory tasks in wake/exec power balancing Alex Shi
2013-02-18 8:44 ` Joonsoo Kim
2013-02-18 8:56 ` Alex Shi
2013-02-20 5:55 ` Alex Shi
2013-02-20 7:40 ` Mike Galbraith
2013-02-20 8:11 ` Alex Shi
2013-02-20 8:43 ` Mike Galbraith
2013-02-20 8:54 ` Alex Shi
2013-02-18 5:07 ` [patch v5 11/15] sched: add power/performance balance allow flag Alex Shi
2013-02-20 9:48 ` Peter Zijlstra
2013-02-20 12:04 ` Alex Shi
2013-02-20 13:37 ` Peter Zijlstra
2013-02-20 13:48 ` Peter Zijlstra
2013-02-20 14:08 ` Alex Shi
2013-02-20 13:52 ` Alex Shi
2013-02-20 12:12 ` Borislav Petkov
2013-02-20 14:20 ` Alex Shi
2013-02-20 15:22 ` Borislav Petkov
2013-02-21 1:32 ` Alex Shi
2013-02-21 9:42 ` Borislav Petkov
2013-02-21 14:52 ` Alex Shi
2013-02-18 5:07 ` [patch v5 12/15] sched: pull all tasks from source group Alex Shi
2013-02-18 5:07 ` [patch v5 13/15] sched: no balance for prefer_sibling in power scheduling Alex Shi
2013-02-18 5:07 ` [patch v5 14/15] sched: power aware load balance Alex Shi
2013-03-20 4:57 ` Preeti U Murthy
2013-03-21 7:43 ` Alex Shi
2013-03-21 8:41 ` Preeti U Murthy
2013-03-21 9:27 ` Alex Shi
2013-03-21 10:27 ` Preeti U Murthy [this message]
2013-03-22 1:30 ` Alex Shi
2013-03-22 5:14 ` Preeti U Murthy
2013-03-25 4:52 ` Alex Shi
2013-03-29 12:42 ` Preeti U Murthy
2013-03-29 13:39 ` Alex Shi
2013-03-30 11:25 ` Preeti U Murthy
2013-03-30 14:04 ` Alex Shi
2013-03-30 15:31 ` Preeti U Murthy
2013-02-18 5:07 ` [patch v5 15/15] sched: lazy power balance Alex Shi
2013-02-18 7:44 ` [patch v5 0/15] power aware scheduling Alex Shi
2013-02-19 12:08 ` Paul Turner
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