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: Sat, 30 Mar 2013 21:01:56 +0530 [thread overview]
Message-ID: <5157056C.5000705@linux.vnet.ibm.com> (raw)
In-Reply-To: <5156F103.6000508@intel.com>
Hi,
On 03/30/2013 07:34 PM, Alex Shi wrote:
> On 03/30/2013 07:25 PM, Preeti U Murthy wrote:
>>>> I still give the rq->util weight even the nr_running is 0, because some
>>>> transitory tasks may actived on the cpu, but just missed on balancing point.
>>>>
>>>> I just wondering that forgetting rq->util when nr_running = 0 is the
>>>> real root cause if your finding is just on VM and without fixed VCPU to
>>>> CPU pin.
>> I find the same situation on a physical machine too. On a 2 socket, 4
>> core machine as well. In fact, using trace_printks in the load balancing
>> part, I could find that the reason that the load was not getting
>> consolidated onto a socket was because the rq->util of a run-queue with
>> no processes on it, had not decayed to 0, which is why it would consider
>> the socket as overloaded and would rule out power aware balancing.All
>> this was on a physical machine.
>
> Consider of this situation, we may stop account the rq->util when
> nr_running is zero. Tasks will be a bit more compact. but anyway, that's
> powersaving policy.
>
True, the tasks will be packed a bit more compactly, but we can expect
the behaviour of your patchset *defaulting to performance policy when
overloaded*, to come to the rescue of such a situation.
Regards
Preeti U Murthy
next prev parent reply other threads:[~2013-03-30 15:33 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
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 [this message]
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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