From: Patrick Bellasi <patrick.bellasi@arm.com>
To: Quentin Perret <quentin.perret@arm.com>
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 06/14] sched/cpufreq: uclamp: add utilization clamping for RT tasks
Date: Thu, 9 Aug 2018 16:41:56 +0100 [thread overview]
Message-ID: <20180809154156.gdsx2vacjmp6p6dp@darkstar> (raw)
In-Reply-To: <20180807135403.s7jktvxmhycujeht@queper01-lin>
On 07-Aug 14:54, Quentin Perret wrote:
> Hi Patrick,
Hi Quentin!
> On Monday 06 Aug 2018 at 17:39:38 (+0100), Patrick Bellasi wrote:
> > diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c
> > index a7affc729c25..bb25ef66c2d3 100644
> > --- a/kernel/sched/cpufreq_schedutil.c
> > +++ b/kernel/sched/cpufreq_schedutil.c
> > @@ -200,6 +200,7 @@ static unsigned int get_next_freq(struct sugov_policy *sg_policy,
> > static unsigned long sugov_get_util(struct sugov_cpu *sg_cpu)
> > {
> > struct rq *rq = cpu_rq(sg_cpu->cpu);
> > + unsigned long util_cfs, util_rt;
> > unsigned long util, irq, max;
> >
> > sg_cpu->max = max = arch_scale_cpu_capacity(NULL, sg_cpu->cpu);
>
> IIUC, not far below this you should still have something like:
>
> if (rt_rq_is_runnable(&rq->rt))
> return max;
Do you mean that when RT tasks are RUNNABLE we still want to got to
MAX? Not sure to understand... since this patch is actually to clamp
the RT class...
> So you won't reach the actual clamping code at the end of the function
> when a RT task is runnable no?
... mmm... no... this patch is to clamp RT tasks... Am I missing
something?
> Also, I always had the feeling that the default for RT should be
> util_min == 1024, and then users could decide to lower the bar if they
> want to.
Mmm... good point! This would keep the policy unaltered for RT tasks.
I want to keep sched class specific code in uclamp at minimum, but
likely this should be achievable by just properly initializing the
task-specific util_min for RT tasks, if the original task has
UCLAM_NOT_VALID.
> For the specific case of RT, that feels more natural than
> applying a max util clamp IMO. What do you think ?
I'll look better into this for the next posting!
Cheers Patrick
--
#include <best/regards.h>
Patrick Bellasi
next prev parent reply other threads:[~2018-08-09 15:42 UTC|newest]
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 [this message]
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
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
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