Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Subject: Re: [Patch v3 1/7] sched/pelt.c: Add support to track thermal
 pressure
To:     Vincent Guittot <vincent.guittot@linaro.org>
References: <1571014705-19646-1-git-send-email-thara.gopinath@linaro.org>
 <1571014705-19646-2-git-send-email-thara.gopinath@linaro.org>
 <CAKfTPtCCjETcDNdP1xuRJ0w3futRV+J+hqkXgYyPQXzOqnaoVg@mail.gmail.com>
Cc:     Ingo Molnar <mingo@redhat.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Ionela Voinescu <ionela.voinescu@arm.com>,
        Zhang Rui <rui.zhang@intel.com>,
        Eduardo Valentin <edubezval@gmail.com>,
        linux-kernel <linux-kernel@vger.kernel.org>,
        Amit Kachhap <amit.kachhap@gmail.com>,
        Javi Merino <javi.merino@kernel.org>,
        Daniel Lezcano <daniel.lezcano@linaro.org>
From:   Thara Gopinath <thara.gopinath@linaro.org>
Message-ID: <5DA7888C.3050406@linaro.org>
Date:   Wed, 16 Oct 2019 17:15:56 -0400
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101
 Thunderbird/38.5.1
MIME-Version: 1.0
In-Reply-To: <CAKfTPtCCjETcDNdP1xuRJ0w3futRV+J+hqkXgYyPQXzOqnaoVg@mail.gmail.com>
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

Hi Vincent,

Thanks for the review.
On 10/14/2019 09:55 AM, Vincent Guittot wrote:
> Hi Thara,
> 
> On Mon, 14 Oct 2019 at 02:58, Thara Gopinath <thara.gopinath@linaro.org> wrote:
>>
>> Extrapolating on the exisitng framework to track rt/dl utilization using
> 
> s/exisitng/existing/
> 
>> pelt signals, add a similar mechanism to track thermal pressue. The
> 
> s/pessure/pressure/
Will fix all the typo.
> 
>> difference here from rt/dl utilization tracking is that, instead of
>> tracking time spent by a cpu running a rt/dl task through util_avg,
>> the average thermal pressure is tracked through load_avg.
> 
> It would be good to mention why you use load_avg field instead of
> util_avg field: because the signal is weighted with the capped
> capacity and is not binary
> And also explained a bit what capacity refer to
> 
>> In order to track average thermal pressure, a new sched_avg variable
>> avg_thermal is introduced. Function update_thermal_avg can be called
>> to do the periodic bookeeping (accumulate, decay and average)
>> of the thermal pressure.
>>
>> Signed-off-by: Thara Gopinath <thara.gopinath@linaro.org>
>> ---
>>  kernel/sched/pelt.c  | 13 +++++++++++++
>>  kernel/sched/pelt.h  |  7 +++++++
>>  kernel/sched/sched.h |  1 +
>>  3 files changed, 21 insertions(+)
>>
>> diff --git a/kernel/sched/pelt.c b/kernel/sched/pelt.c
>> index a96db50..f06aae3 100644
>> --- a/kernel/sched/pelt.c
>> +++ b/kernel/sched/pelt.c
>> @@ -353,6 +353,19 @@ int update_dl_rq_load_avg(u64 now, struct rq *rq, int running)
>>         return 0;
>>  }
>>
>> +int update_thermal_avg(u64 now, struct rq *rq, u64 capacity)
> 
> All the other functions are named :
> update_cfs_rq/rt_rq/dl_rq/irq_load_avg
> 
> might be good to keep similar name with update_thermal_load_avg

Sure. Will rename the function.
> 
>> +{
>> +       if (___update_load_sum(now, &rq->avg_thermal,
>> +                              capacity,
>> +                              capacity,
>> +                              capacity)) {
>> +               ___update_load_avg(&rq->avg_thermal, 1, 1);
>> +               return 1;
>> +       }
>> +
>> +       return 0;
>> +}
>> +
>>  #ifdef CONFIG_HAVE_SCHED_AVG_IRQ
>>  /*
>>   * irq:
>> diff --git a/kernel/sched/pelt.h b/kernel/sched/pelt.h
>> index afff644..01c5436 100644
>> --- a/kernel/sched/pelt.h
>> +++ b/kernel/sched/pelt.h
>> @@ -6,6 +6,7 @@ int __update_load_avg_se(u64 now, struct cfs_rq *cfs_rq, struct sched_entity *se
>>  int __update_load_avg_cfs_rq(u64 now, struct cfs_rq *cfs_rq);
>>  int update_rt_rq_load_avg(u64 now, struct rq *rq, int running);
>>  int update_dl_rq_load_avg(u64 now, struct rq *rq, int running);
>> +int update_thermal_avg(u64 now, struct rq *rq, u64 capacity);
>>
>>  #ifdef CONFIG_HAVE_SCHED_AVG_IRQ
>>  int update_irq_load_avg(struct rq *rq, u64 running);
>> @@ -175,6 +176,12 @@ update_rq_clock_pelt(struct rq *rq, s64 delta) { }
>>  static inline void
>>  update_idle_rq_clock_pelt(struct rq *rq) { }
>>
>> +static inline int
> 
> can you keep some function ordering as above and move
> update_thermal_avg() just after update_dl_rq_load_avg

will do.

Warm Regards
Thara