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, 4 Sep 2015 09:26:42 +0200 [thread overview]
Message-ID: <CAKfTPtBnj9_oHoXEZFnYnsxb5a3KwPcVHYydRVQEzypkCbJakQ@mail.gmail.com> (raw)
In-Reply-To: <55E8A65F.2070903@arm.com>
On 3 September 2015 at 21:58, Dietmar Eggemann <dietmar.eggemann@arm.com> wrote:
> Hi Vincent,
>
> On 02/09/15 10:31, Vincent Guittot wrote:
>> Hi Morten,
>>
>> On 14 August 2015 at 18:23, Morten Rasmussen <morten.rasmussen@arm.com> wrote:
>>> Bring arch_scale_cpu_capacity() in line with the recent change of its
>>> arch_scale_freq_capacity() sibling in commit dfbca41f3479 ("sched:
>>> Optimize freq invariant accounting") from weak function to #define to
>>> allow inlining of the function.
>>>
>>> While at it, remove the ARCH_CAPACITY sched_feature as well. With the
>>> change to #define there isn't a straightforward way to allow runtime
>>> switch between an arch implementation and the default implementation of
>>> arch_scale_cpu_capacity() using sched_feature. The default was to use
>>> the arch-specific implementation, but only the arm architecture provides
>>> one and that is essentially equivalent to the default implementation.
>
> [...]
>
>>
>> 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
>
> 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.
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.
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
>
> 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:[~2015-09-04 7:27 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 [this message]
2015-09-07 13:25 ` Dietmar Eggemann
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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