From: Dietmar Eggemann <dietmar.eggemann@arm.com>
To: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Morten Rasmussen <Morten.Rasmussen@arm.com>,
Peter Zijlstra <peterz@infradead.org>,
"mingo@redhat.com" <mingo@redhat.com>,
Daniel Lezcano <daniel.lezcano@linaro.org>,
Yuyang Du <yuyang.du@intel.com>,
Michael Turquette <mturquette@baylibre.com>,
"rjw@rjwysocki.net" <rjw@rjwysocki.net>,
Juri Lelli <Juri.Lelli@arm.com>,
Sai Charan Gurrappadi <sgurrappadi@nvidia.com>,
"pang.xunlei@zte.com.cn" <pang.xunlei@zte.com.cn>,
linux-kernel <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 2/6] sched/fair: Convert arch_scale_cpu_capacity() from weak function to #define
Date: Mon, 7 Sep 2015 14:25:11 +0100 [thread overview]
Message-ID: <55ED9037.8050702@arm.com> (raw)
In-Reply-To: <CAKfTPtBnj9_oHoXEZFnYnsxb5a3KwPcVHYydRVQEzypkCbJakQ@mail.gmail.com>
On 04/09/15 08:26, Vincent Guittot wrote:
> On 3 September 2015 at 21:58, Dietmar Eggemann <dietmar.eggemann@arm.com> wrote:
[...]
>>> So you change the way to declare arch_scale_cpu_capacity but i don't
>>> see the update of the arm arch which declare a
>>> arch_scale_cpu_capacity to reflect this change in your series.
>>
>> We were reluctant to do this because this functionality makes only sense
>> for ARCH=arm big.Little systems w/ cortex-a{15|7} cores and only if the
>> clock-frequency property is set in the dts file.
>
> IMO, we should maintain the compatibility of current implementation
> instead of breaking the link and creating a dead code.
> Your proposal below fits the requirement
The only problem with this solution is that now we got a call to
arch_scale_cpu_capacity() in the hotpath whereas before it is only
called in update_cpu_capacity(). An implementation of
scale_cpu_capacity() in arch/arm/kernel/topology.c leads to a function
call in __update_load_avg. I'm in the middle of doing some performance
tests on TC2 w/ and w/o the cpu invariant implementation.
>
>>
>> Are you planning to push for a 'struct cpu_efficiency/clock-frequency
>> property' solution for ARCH=arm64 as well?
>
> I know that there has been some discussions aorund that but i didn't
> follow the thread in details
>
>>
>> I'm asking because for ARCH=arm64 systems today (JUNO, Hi6220) we use the
>> capacity value of the last entry of the capacity_state vector for the cores
>> (e.g. cortex-a{57|53).
>
> This is a struct of the eas feature ? Not sure that we should link the
> definition of the cpu capacity to an internal struct of a feature; DT
> seems a better way to define it.
Yeah, the cpu invariant functionality should not base on EAS. We just
use the short-cut in EAS RFCv5 to get it working on ARM64.
> So if you want to revisit the way, we set the capacity of CPU for arm
> and/or arm64, I'm fully open to the discussion but this should happen
> in another thread than this one which has for only purpose the
> alignment of the arch_scale_cpu_capacity interface declaration with
> arch_scale_freq_capacity one.
Agreed.
>
> So, with the patch below that updates the arm definition of
> arch_scale_cpu_capacity, you can add my Acked-by: Vincent Guittot
> <vincent.guittot@linaro.org> on this patch and the additional one
> below
>
> Regards,
> Vincent
[...]
next prev parent reply other threads:[~2015-09-07 13:25 UTC|newest]
Thread overview: 97+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-08-14 16:23 [PATCH 0/6] sched/fair: Compute capacity invariant load/utilization tracking Morten Rasmussen
2015-08-14 16:23 ` [PATCH 1/6] sched/fair: Make load tracking frequency scale-invariant Morten Rasmussen
2015-09-13 11:03 ` [tip:sched/core] " tip-bot for Dietmar Eggemann
2015-08-14 16:23 ` [PATCH 2/6] sched/fair: Convert arch_scale_cpu_capacity() from weak function to #define Morten Rasmussen
2015-09-02 9:31 ` Vincent Guittot
2015-09-02 12:41 ` Vincent Guittot
2015-09-03 19:58 ` Dietmar Eggemann
2015-09-04 7:26 ` Vincent Guittot
2015-09-07 13:25 ` Dietmar Eggemann [this message]
2015-09-11 13:21 ` Dietmar Eggemann
2015-09-11 14:45 ` Vincent Guittot
2015-09-13 11:03 ` [tip:sched/core] " tip-bot for Morten Rasmussen
2015-08-14 16:23 ` [PATCH 3/6] sched/fair: Make utilization tracking cpu scale-invariant Morten Rasmussen
2015-08-14 23:04 ` Dietmar Eggemann
2015-09-04 7:52 ` Vincent Guittot
2015-09-13 11:04 ` [tip:sched/core] sched/fair: Make utilization tracking CPU scale-invariant tip-bot for Dietmar Eggemann
2015-08-14 16:23 ` [PATCH 4/6] sched/fair: Name utilization related data and functions consistently Morten Rasmussen
2015-09-04 9:08 ` Vincent Guittot
2015-09-11 16:35 ` Dietmar Eggemann
2015-09-13 11:04 ` [tip:sched/core] " tip-bot for Dietmar Eggemann
2015-08-14 16:23 ` [PATCH 5/6] sched/fair: Get rid of scaling utilization by capacity_orig Morten Rasmussen
2015-09-03 23:51 ` Steve Muckle
2015-09-07 15:37 ` Dietmar Eggemann
2015-09-07 16:21 ` Vincent Guittot
2015-09-07 18:54 ` Dietmar Eggemann
2015-09-07 19:47 ` Peter Zijlstra
2015-09-08 12:47 ` Dietmar Eggemann
2015-09-08 7:22 ` Vincent Guittot
2015-09-08 12:26 ` Peter Zijlstra
2015-09-08 12:52 ` Peter Zijlstra
2015-09-08 14:06 ` Vincent Guittot
2015-09-08 14:35 ` Morten Rasmussen
2015-09-08 14:40 ` Vincent Guittot
2015-09-08 14:31 ` Morten Rasmussen
2015-09-08 15:33 ` Peter Zijlstra
2015-09-09 22:23 ` bsegall
2015-09-10 11:06 ` Morten Rasmussen
2015-09-10 11:11 ` Vincent Guittot
2015-09-10 12:10 ` Morten Rasmussen
2015-09-11 0:50 ` Yuyang Du
2015-09-10 17:23 ` bsegall
2015-09-08 16:53 ` Morten Rasmussen
2015-09-09 9:43 ` Peter Zijlstra
2015-09-09 9:45 ` Peter Zijlstra
2015-09-09 11:13 ` Morten Rasmussen
2015-09-11 17:22 ` Morten Rasmussen
2015-09-17 9:51 ` Peter Zijlstra
2015-09-17 10:38 ` Peter Zijlstra
2015-09-21 1:16 ` Yuyang Du
2015-09-21 17:30 ` bsegall
2015-09-21 23:39 ` Yuyang Du
2015-09-22 17:18 ` bsegall
2015-09-22 23:22 ` Yuyang Du
2015-09-23 16:54 ` bsegall
2015-09-24 0:22 ` Yuyang Du
2015-09-30 12:52 ` Peter Zijlstra
2015-09-11 7:46 ` Leo Yan
2015-09-11 10:02 ` Morten Rasmussen
2015-09-11 14:11 ` Leo Yan
2015-09-09 19:07 ` Yuyang Du
2015-09-10 10:06 ` Peter Zijlstra
2015-09-08 13:39 ` Vincent Guittot
2015-09-08 14:10 ` Peter Zijlstra
2015-09-08 15:17 ` Vincent Guittot
2015-09-08 12:50 ` Dietmar Eggemann
2015-09-08 14:01 ` Vincent Guittot
2015-09-08 14:27 ` Dietmar Eggemann
2015-09-09 20:15 ` Yuyang Du
2015-09-10 10:07 ` Peter Zijlstra
2015-09-11 0:28 ` Yuyang Du
2015-09-11 10:31 ` Morten Rasmussen
2015-09-11 17:05 ` bsegall
2015-09-11 18:24 ` Yuyang Du
2015-09-14 17:36 ` bsegall
2015-09-14 12:56 ` Morten Rasmussen
2015-09-14 17:34 ` bsegall
2015-09-14 22:56 ` Yuyang Du
2015-09-15 17:11 ` bsegall
2015-09-15 18:39 ` Yuyang Du
2015-09-16 17:06 ` bsegall
2015-09-17 2:31 ` Yuyang Du
2015-09-15 8:43 ` Morten Rasmussen
2015-09-16 15:36 ` Peter Zijlstra
2015-09-08 11:44 ` Peter Zijlstra
2015-09-13 11:04 ` [tip:sched/core] " tip-bot for Dietmar Eggemann
2015-08-14 16:23 ` [PATCH 6/6] sched/fair: Initialize task load and utilization before placing task on rq Morten Rasmussen
2015-09-13 11:05 ` [tip:sched/core] " tip-bot for Morten Rasmussen
2015-08-16 20:46 ` [PATCH 0/6] sched/fair: Compute capacity invariant load/utilization tracking Peter Zijlstra
2015-08-17 11:29 ` Morten Rasmussen
2015-08-17 11:48 ` Peter Zijlstra
2015-08-31 9:24 ` Peter Zijlstra
2015-09-02 9:51 ` Dietmar Eggemann
2015-09-07 12:42 ` Peter Zijlstra
2015-09-07 13:21 ` Peter Zijlstra
2015-09-07 13:23 ` Peter Zijlstra
2015-09-07 14:44 ` Dietmar Eggemann
2015-09-13 11:06 ` [tip:sched/core] sched/fair: Defer calling scaling functions tip-bot for Dietmar Eggemann
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