Linux-PM Archive on lore.kernel.org
 help / color / Atom feed
From: Douglas Raillard <douglas.raillard@arm.com>
To: Dietmar Eggemann <dietmar.eggemann@arm.com>,
	linux-kernel@vger.kernel.org
Cc: linux-pm@vger.kernel.org, mingo@redhat.com, peterz@infradead.org,
	rjw@rjwysocki.net, viresh.kumar@linaro.org,
	juri.lelli@redhat.com, vincent.guittot@linaro.org,
	qperret@qperret.net, patrick.bellasi@matbug.net,
	dh.han@samsung.com
Subject: Re: [RFC PATCH v3 2/6] sched/cpufreq: Attach perf domain to sugov policy
Date: Thu, 17 Oct 2019 11:22:16 +0100
Message-ID: <686407a7-3074-0fa2-e041-a9931f467aea@arm.com> (raw)
In-Reply-To: <4ebf6419-c8e0-3998-41e0-3f7b49b34084@arm.com>

Hi Dietmar,

On 10/17/19 9:57 AM, Dietmar Eggemann wrote:
> On 11/10/2019 15:44, Douglas RAILLARD wrote:
> 
> [...]
> 
>> @@ -66,6 +70,38 @@ static DEFINE_PER_CPU(struct sugov_cpu, sugov_cpu);
>>   
>>   /************************ Governor internals ***********************/
>>   
>> +#ifdef CONFIG_ENERGY_MODEL
>> +static void sugov_policy_attach_pd(struct sugov_policy *sg_policy)
>> +{
>> +	struct em_perf_domain *pd;
>> +	struct cpufreq_policy *policy = sg_policy->policy;
> 
> Shouldn't always order local variable declarations from longest to
> shortest line?

Can't find any reference to that rule in the coding style, although I'm happy to change order
if that's deemed useful.

> 
>> +
>> +	sg_policy->pd = NULL;
>> +	pd = em_cpu_get(policy->cpu);
>> +	if (!pd)
>> +		return;
>> +
>> +	if (cpumask_equal(policy->related_cpus, to_cpumask(pd->cpus)))
>> +		sg_policy->pd = pd;
>> +	else
>> +		pr_warn("%s: Not all CPUs in schedutil policy %u share the same perf domain, no perf domain for that policy will be registered\n",
>> +			__func__, policy->cpu);
> 
> Maybe {} because of 2 lines?

+1

>> +}
>> +
>> +static struct em_perf_domain *sugov_policy_get_pd(
>> +						struct sugov_policy *sg_policy)
> 
> 
> Maybe this way? This format is already used in this file.
> 
> static struct em_perf_domain *
> sugov_policy_get_pd(struct sugov_policy *sg_policy)
> 

I also prefer this kind of non-indented form that always stays indented across renames :)

>> +{
>> +	return sg_policy->pd;
>> +}
>> +#else /* CONFIG_ENERGY_MODEL */
>> +static void sugov_policy_attach_pd(struct sugov_policy *sg_policy) {}
>> +static struct em_perf_domain *sugov_policy_get_pd(
>> +						struct sugov_policy *sg_policy)
>> +{
>> +	return NULL;
>> +}
>> +#endif /* CONFIG_ENERGY_MODEL */
>> +
>>   static bool sugov_should_update_freq(struct sugov_policy *sg_policy, u64 time)
>>   {
>>   	s64 delta_ns;
>> @@ -859,6 +895,9 @@ static int sugov_start(struct cpufreq_policy *policy)
>>   							sugov_update_shared :
>>   							sugov_update_single);
>>   	}
>> +
>> +	sugov_policy_attach_pd(sg_policy);
>> +
>>   	return 0;
>>   }
> 
> A sugov_policy_detach_pd() called from sugov_stop() (doing for instance
> the g_policy->pd = NULL) is not needed?

 From what I could see, sugov_stop() will always be followed by sugov_start() before
it's used again, so that does not seem more risky than not de-initializing sg_cpu's
for example.

  reply index

Thread overview: 35+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-10-11 13:44 [RFC PATCH v3 0/6] sched/cpufreq: Make schedutil energy aware Douglas RAILLARD
2019-10-11 13:44 ` [RFC PATCH v3 1/6] PM: Introduce em_pd_get_higher_freq() Douglas RAILLARD
2019-10-17  8:57   ` Dietmar Eggemann
2019-10-17  9:58   ` Dietmar Eggemann
2019-10-17 11:09     ` Douglas Raillard
2019-10-11 13:44 ` [RFC PATCH v3 2/6] sched/cpufreq: Attach perf domain to sugov policy Douglas RAILLARD
2019-10-17  8:57   ` Dietmar Eggemann
2019-10-17 10:22     ` Douglas Raillard [this message]
2019-10-11 13:44 ` [RFC PATCH v3 3/6] sched/cpufreq: Hook em_pd_get_higher_power() into get_next_freq() Douglas RAILLARD
2019-10-11 13:44 ` [RFC PATCH v3 4/6] sched/cpufreq: Introduce sugov_cpu_ramp_boost Douglas RAILLARD
2019-10-14 14:33   ` Peter Zijlstra
2019-10-14 15:32     ` Douglas Raillard
2019-10-17  8:57   ` Dietmar Eggemann
2019-10-17 11:19     ` Douglas Raillard
2019-10-11 13:44 ` [RFC PATCH v3 5/6] sched/cpufreq: Boost schedutil frequency ramp up Douglas RAILLARD
2019-10-17  9:21   ` Dietmar Eggemann
2019-10-11 13:45 ` [RFC PATCH v3 6/6] sched/cpufreq: Add schedutil_em_tp tracepoint Douglas RAILLARD
2019-10-14 14:53 ` [RFC PATCH v3 0/6] sched/cpufreq: Make schedutil energy aware Peter Zijlstra
2019-10-14 15:50   ` Douglas Raillard
2019-10-17  9:50     ` Peter Zijlstra
2019-10-17 11:11       ` Quentin Perret
2019-10-17 14:11         ` Peter Zijlstra
2019-10-18  7:44           ` Dietmar Eggemann
2019-10-18  7:59             ` Peter Zijlstra
2019-10-18 17:24               ` Douglas Raillard
2019-10-18  8:11             ` Peter Zijlstra
2019-10-17 14:23       ` Douglas Raillard
2019-10-17 14:53         ` Peter Zijlstra
2019-10-17 19:07         ` Peter Zijlstra
2019-10-18 11:46           ` Douglas Raillard
2019-10-18 12:07             ` Peter Zijlstra
2019-10-18 14:44               ` Douglas Raillard
2019-10-18 15:15                 ` Vincent Guittot
2019-10-18 16:03                   ` Douglas Raillard
2019-10-18 15:20                 ` Vincent Guittot

Reply instructions:

You may reply publically to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=686407a7-3074-0fa2-e041-a9931f467aea@arm.com \
    --to=douglas.raillard@arm.com \
    --cc=dh.han@samsung.com \
    --cc=dietmar.eggemann@arm.com \
    --cc=juri.lelli@redhat.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-pm@vger.kernel.org \
    --cc=mingo@redhat.com \
    --cc=patrick.bellasi@matbug.net \
    --cc=peterz@infradead.org \
    --cc=qperret@qperret.net \
    --cc=rjw@rjwysocki.net \
    --cc=vincent.guittot@linaro.org \
    --cc=viresh.kumar@linaro.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux-PM Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-pm/0 linux-pm/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-pm linux-pm/ https://lore.kernel.org/linux-pm \
		linux-pm@vger.kernel.org
	public-inbox-index linux-pm

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-pm


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git