LKML Archive on lore.kernel.org
 help / Atom feed
From: Patrick Bellasi <patrick.bellasi@arm.com>
To: Pavan Kondeti <pkondeti@codeaurora.org>
Cc: linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org,
	Ingo Molnar <mingo@redhat.com>,
	Peter Zijlstra <peterz@infradead.org>, Tejun Heo <tj@kernel.org>,
	"Rafael J . Wysocki" <rafael.j.wysocki@intel.com>,
	Viresh Kumar <viresh.kumar@linaro.org>,
	Vincent Guittot <vincent.guittot@linaro.org>,
	Paul Turner <pjt@google.com>,
	Dietmar Eggemann <dietmar.eggemann@arm.com>,
	Morten Rasmussen <morten.rasmussen@arm.com>,
	Juri Lelli <juri.lelli@redhat.com>, Todd Kjos <tkjos@google.com>,
	Joel Fernandes <joelaf@google.com>,
	Steve Muckle <smuckle@google.com>,
	Suren Baghdasaryan <surenb@google.com>
Subject: Re: [PATCH v3 09/14] sched/core: uclamp: propagate parent clamps
Date: Thu, 16 Aug 2018 15:07:31 +0100
Message-ID: <20180816140731.GD2960@e110439-lin> (raw)
In-Reply-To: <20180816090906.GC2661@codeaurora.org>

On 16-Aug 14:39, Pavan Kondeti wrote:
> On Mon, Aug 06, 2018 at 05:39:41PM +0100, Patrick Bellasi wrote:

[...]

> > diff --git a/include/linux/sched.h b/include/linux/sched.h
> > index 8f48e64fb8a6..3fac2d098084 100644
> > --- a/include/linux/sched.h
> > +++ b/include/linux/sched.h
> > @@ -589,6 +589,11 @@ struct uclamp_se {
> >  	unsigned int value;
> >  	/* Utilization clamp group for this constraint */
> >  	unsigned int group_id;
> > +	/* Effective clamp  for tasks in this group */
> > +	struct {
> > +		unsigned int value;
> > +		unsigned int group_id;
> > +	} effective;
> >  };
> 
> Are these needed when CONFIG_UCLAMP_TASK_GROUP is disabled?

Mmm... not entirely, at least not the value.

While working on v4 I've notice that:

   (1) task_struct::uclamp::effective::group_id

can be used for the back annotation we add in:

   [PATCH v3 11/14] sched/core: uclamp: use TG's clamps to restrict Task's clamps

using the additional field:

   (2) task_struct::uclamp_group_id

So, I'm updating that patch to re-use (1) instead of adding (2).

Regarding:

   (3) task_struct::uclamp::effective::value

it can be used to track the task's effective clamp value once I add
the discretization support discussed with Juri in:

   https://lore.kernel.org/lkml/20180809152313.lewfhufidhxb2qrk@darkstar/


So, I would say that in v4 I can try to see if and how we can guard
(some of) the effective values on !CONFIG_UCLAMP_TASK_GROUP
configurations...

>
> >  union rcu_special {
> > diff --git a/kernel/sched/core.c b/kernel/sched/core.c
> > index 2ba55a4afffb..f692df3787bd 100644
> > --- a/kernel/sched/core.c
> > +++ b/kernel/sched/core.c
> > @@ -1237,6 +1237,8 @@ static inline void init_uclamp_sched_group(void)
> >  		uc_se = &root_task_group.uclamp[clamp_id];
> >  		uc_se->value = uclamp_none(clamp_id);
> >  		uc_se->group_id = group_id;
> > +		uc_se->effective.value = uclamp_none(clamp_id);
> > +		uc_se->effective.group_id = group_id;
> >  
> >  		/* Attach root TG's clamp group */
> >  		uc_map[group_id].se_count = 1;
> >  
> 
> <snip>
> 
> > @@ -7622,11 +7687,19 @@ static struct cftype cpu_legacy_files[] = {
> >  		.read_u64 = cpu_util_min_read_u64,
> >  		.write_u64 = cpu_util_min_write_u64,
> >  	},
> > +	{
> > +		.name = "util.min.effective",
> > +		.read_u64 = cpu_util_min_effective_read_u64,
> > +	},
> >  	{
> >  		.name = "util.max",
> >  		.read_u64 = cpu_util_max_read_u64,
> >  		.write_u64 = cpu_util_max_write_u64,
> >  	},
> > +	{
> > +		.name = "util.max.effective",
> > +		.read_u64 = cpu_util_max_effective_read_u64,
> > +	},
> >  #endif
> >  	{ }	/* Terminate */
> >  };
> 
> Is there any reason why these are not added for the default hierarchy?

Not really, good point!

I think I've just forgot them... which makes me notice that I still
have to improve the coverage for my tests on the default hierarchy.

I don't expect big difference, since the behaviors should be the
same but...

Thanks for pointing this out... will had the attributes in the
upcoming v4.

Cheers,
Patrick

-- 
#include <best/regards.h>

Patrick Bellasi

  reply index

Thread overview: 82+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-08-06 16:39 [PATCH v3 00/14] Add utilization clamping support Patrick Bellasi
2018-08-06 16:39 ` [PATCH v3 01/14] sched/core: uclamp: extend sched_setattr to support utilization clamping Patrick Bellasi
2018-08-06 16:50   ` Randy Dunlap
2018-08-09  8:39     ` Patrick Bellasi
2018-08-09 15:20       ` Randy Dunlap
2018-08-07  9:59   ` Juri Lelli
2018-08-13 12:14     ` Patrick Bellasi
2018-08-13 12:27       ` Juri Lelli
2018-08-07 12:35   ` Juri Lelli
2018-08-09  9:14     ` Patrick Bellasi
2018-08-09  9:50       ` Juri Lelli
2018-08-09 15:23         ` Patrick Bellasi
2018-08-10  7:50           ` Juri Lelli
2018-08-17 10:34           ` Quentin Perret
2018-08-17 10:57             ` Patrick Bellasi
2018-08-17 11:14               ` Quentin Perret
2018-08-06 16:39 ` [PATCH v3 02/14] sched/core: uclamp: map TASK's clamp values into CPU's clamp groups Patrick Bellasi
2018-08-14 11:25   ` Pavan Kondeti
2018-08-14 15:21     ` Patrick Bellasi
2018-08-06 16:39 ` [PATCH v3 03/14] sched/core: uclamp: add CPU's clamp groups accounting Patrick Bellasi
2018-08-14 15:44   ` Dietmar Eggemann
2018-08-14 16:49     ` Patrick Bellasi
2018-08-15  9:37       ` Dietmar Eggemann
2018-08-15 10:54         ` Patrick Bellasi
2018-08-15 10:59           ` Dietmar Eggemann
2018-08-16 13:32             ` Patrick Bellasi
2018-08-16 13:37               ` Quentin Perret
2018-08-16 13:45                 ` Dietmar Eggemann
2018-08-16 14:21                   ` Quentin Perret
2018-08-16 15:00                     ` Dietmar Eggemann
2018-08-17 11:04   ` Patrick Bellasi
2018-08-06 16:39 ` [PATCH v3 04/14] sched/core: uclamp: update CPU's refcount on clamp changes Patrick Bellasi
2018-08-15 15:02   ` Dietmar Eggemann
2018-08-16 13:22     ` Patrick Bellasi
2018-08-06 16:39 ` [PATCH v3 05/14] sched/cpufreq: uclamp: add utilization clamping for FAIR tasks Patrick Bellasi
2018-08-08 13:18   ` Vincent Guittot
2018-08-09 15:30     ` Patrick Bellasi
2018-08-15 15:30   ` Dietmar Eggemann
2018-08-16 13:53     ` Patrick Bellasi
2018-08-06 16:39 ` [PATCH v3 06/14] sched/cpufreq: uclamp: add utilization clamping for RT tasks Patrick Bellasi
2018-08-07 13:26   ` Juri Lelli
2018-08-09 15:34     ` Patrick Bellasi
2018-08-09 16:03       ` Vincent Guittot
2018-08-13 10:12         ` Patrick Bellasi
2018-08-13 10:50           ` Juri Lelli
2018-08-13 12:07           ` Vincent Guittot
2018-08-13 12:09             ` Vincent Guittot
2018-08-13 12:49             ` Patrick Bellasi
2018-08-13 14:06               ` Vincent Guittot
2018-08-13 15:01                 ` Patrick Bellasi
2018-08-16 10:34                   ` Dietmar Eggemann
2018-08-16 13:40                     ` Patrick Bellasi
2018-08-07 13:54   ` Quentin Perret
2018-08-09 15:41     ` Patrick Bellasi
2018-08-09 15:55       ` Quentin Perret
2018-08-13 10:17         ` Patrick Bellasi
2018-08-06 16:39 ` [PATCH v3 07/14] sched/core: uclamp: enforce last task UCLAMP_MAX Patrick Bellasi
2018-08-16 15:43   ` Dietmar Eggemann
2018-08-16 16:47     ` Patrick Bellasi
2018-08-16 17:10       ` Dietmar Eggemann
2018-08-16 17:27         ` Patrick Bellasi
2018-08-16 17:20   ` Patrick Bellasi
2018-08-06 16:39 ` [PATCH v3 08/14] sched/core: uclamp: extend cpu's cgroup controller Patrick Bellasi
2018-08-17 12:21   ` Dietmar Eggemann
2018-08-17 14:24     ` Patrick Bellasi
2018-08-06 16:39 ` [PATCH v3 09/14] sched/core: uclamp: propagate parent clamps Patrick Bellasi
2018-08-16  9:09   ` Pavan Kondeti
2018-08-16 14:07     ` Patrick Bellasi [this message]
2018-08-17 13:43   ` Dietmar Eggemann
2018-08-17 14:45     ` Patrick Bellasi
2018-08-17 15:50       ` Dietmar Eggemann
2018-08-20 10:01         ` Dietmar Eggemann
2018-08-20 12:28           ` Patrick Bellasi
2018-08-06 16:39 ` [PATCH v3 10/14] sched/core: uclamp: map TG's clamp values into CPU's clamp groups Patrick Bellasi
2018-08-06 16:39 ` [PATCH v3 11/14] sched/core: uclamp: use TG's clamps to restrict Task's clamps Patrick Bellasi
2018-08-06 16:39 ` [PATCH v3 12/14] sched/core: uclamp: add system default clamps Patrick Bellasi
2018-08-16  9:13   ` Pavan Kondeti
2018-08-16 14:37     ` Patrick Bellasi
2018-08-20 10:18   ` Dietmar Eggemann
2018-08-20 12:27     ` Patrick Bellasi
2018-08-06 16:39 ` [PATCH v3 13/14] sched/core: uclamp: update CPU's refcount on TG's clamp changes Patrick Bellasi
2018-08-06 16:39 ` [PATCH v3 14/14] sched/core: uclamp: use percentage clamp values Patrick Bellasi

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=20180816140731.GD2960@e110439-lin \
    --to=patrick.bellasi@arm.com \
    --cc=dietmar.eggemann@arm.com \
    --cc=joelaf@google.com \
    --cc=juri.lelli@redhat.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-pm@vger.kernel.org \
    --cc=mingo@redhat.com \
    --cc=morten.rasmussen@arm.com \
    --cc=peterz@infradead.org \
    --cc=pjt@google.com \
    --cc=pkondeti@codeaurora.org \
    --cc=rafael.j.wysocki@intel.com \
    --cc=smuckle@google.com \
    --cc=surenb@google.com \
    --cc=tj@kernel.org \
    --cc=tkjos@google.com \
    --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

LKML Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/lkml/0 lkml/git/0.git
	git clone --mirror https://lore.kernel.org/lkml/1 lkml/git/1.git
	git clone --mirror https://lore.kernel.org/lkml/2 lkml/git/2.git
	git clone --mirror https://lore.kernel.org/lkml/3 lkml/git/3.git
	git clone --mirror https://lore.kernel.org/lkml/4 lkml/git/4.git
	git clone --mirror https://lore.kernel.org/lkml/5 lkml/git/5.git
	git clone --mirror https://lore.kernel.org/lkml/6 lkml/git/6.git

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


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


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