From: Vincent Guittot <vincent.guittot@linaro.org>
To: Dietmar Eggemann <dietmar.eggemann@arm.com>
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: Fri, 11 Sep 2015 16:45:49 +0200 [thread overview]
Message-ID: <CAKfTPtBkrpHVKZ3kx9JrvtYoD6rkDD8c2=p0hJ39U3SBBe5fSQ@mail.gmail.com> (raw)
In-Reply-To: <55F2D55C.6040202@arm.com>
On 11 September 2015 at 15:21, Dietmar Eggemann
<dietmar.eggemann@arm.com> wrote:
> On 04/09/15 08:26, Vincent Guittot wrote:
>> On 3 September 2015 at 21:58, Dietmar Eggemann <dietmar.eggemann@arm.com> wrote:
>
> [...]
>
>> 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
>
> My tests on ARM TC2 (only the 2 A15's) show that the influence of the
> non-default arch_scale_cpu_capacity function in
> arch/arm/kernel/topology.c and with it the extra function call to it
> from __update_load_avg() has no measurable influence on performance:
>
> perf stat --null --repeat 10 -- perf bench sched messaging --g 50 -l 200
>
> - default arch_scale_cpu_capacity function [kernel/sched/sched.h]
>
> 16.006976251 seconds time elapsed ( +- 0.29% )
> 16.063814914 seconds time elapsed ( +- 0.37% )
> 16.088199252 seconds time elapsed ( +- 0.39% )
>
> - arch_scale_cpu_capacity function [arch/arm/kernel/topology.c]
>
> 15.945975308 seconds time elapsed ( +- 0.10% )
> 16.131203074 seconds time elapsed ( +- 0.21% )
> 16.108302562 seconds time elapsed ( +- 0.41% )
>
> If I force the function to be inline, the result is slightly worse:
>
> - arch_scale_cpu_capacity function [arch/arm/include/asm/topology.h]
>
> 16.122545216 seconds time elapsed ( +- 0.09% )
> 16.285819258 seconds time elapsed ( +- 0.35% )
> 16.157454024 seconds time elapsed ( +- 0.15% )
>
> So I think we can connect the arch_scale_cpu_capacity function
> [arch/arm/kernel/topology.c] to the CFS scheduler for ARCH=arm so that
> people get cpu scale different to 1024 on arm big.little machines w/
> A15/A7 in case the specify clock-frequency properties in their dtb file.
>
> Can we still have your 'Acked-by' for this patch and 3/6 even though we
> now scale weight (by frequency) and scale_freq (by cpu) instead of the
> time related values (delta_w, contrib, delta)?
Yes, Please add my Acked-by
Vincent
>
> Thanks,
>
> -- Dietmar
>
>>
>> Regards,
>> Vincent
>>
>>>
>>> To connect the cpu invariant engine (scale_cpu_capacity()
>>> [arch/arm/kernel/topology.c]) with the scheduler, something like this is
>>> missing:
>>>
>>> diff --git a/arch/arm/include/asm/topology.h b/arch/arm/include/asm/topology.h
>>> index 370f7a732900..17c6b3243196 100644
>>> --- a/arch/arm/include/asm/topology.h
>>> +++ b/arch/arm/include/asm/topology.h
>>> @@ -24,6 +24,10 @@ void init_cpu_topology(void);
>>> void store_cpu_topology(unsigned int cpuid);
>>> const struct cpumask *cpu_coregroup_mask(int cpu);
>>>
>>> +#define arch_scale_cpu_capacity scale_cpu_capacity
>>> +struct sched_domain;
>>> +extern unsigned long scale_cpu_capacity(struct sched_domain *sd, int cpu);
>>> +
>>> #else
>>>
>>> static inline void init_cpu_topology(void) { }
>>> diff --git a/arch/arm/kernel/topology.c b/arch/arm/kernel/topology.c
>>> index 08b7847bf912..907e0d2d9b82 100644
>>> --- a/arch/arm/kernel/topology.c
>>> +++ b/arch/arm/kernel/topology.c
>>> @@ -42,7 +42,7 @@
>>> */
>>> static DEFINE_PER_CPU(unsigned long, cpu_scale);
>>>
>>> -unsigned long arch_scale_cpu_capacity(struct sched_domain *sd, int cpu)
>>> +unsigned long scale_cpu_capacity(struct sched_domain *sd, int cpu)
>>> {
>>> return per_cpu(cpu_scale, cpu);
>>> }
>>> @@ -166,7 +166,7 @@ static void update_cpu_capacity(unsigned int cpu)
>>> set_capacity_scale(cpu, cpu_capacity(cpu) / middle_capacity);
>>>
>>> pr_info("CPU%u: update cpu_capacity %lu\n",
>>> - cpu, arch_scale_cpu_capacity(NULL, cpu));
>>> + cpu, scale_cpu_capacity(NULL, cpu));
>>> }
>>>
>>> -- Dietmar
>>>
>>> [...]
>
next prev parent reply other threads:[~2015-09-11 14:46 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
2015-09-11 13:21 ` Dietmar Eggemann
2015-09-11 14:45 ` Vincent Guittot [this message]
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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