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From: Juri Lelli <juri.lelli@gmail.com>
To: Quentin Perret <quentin.perret@arm.com>
Cc: Patrick Bellasi <patrick.bellasi@arm.com>,
	Dietmar Eggemann <dietmar.eggemann@arm.com>,
	linux-kernel@vger.kernel.org,
	Peter Zijlstra <peterz@infradead.org>,
	Thara Gopinath <thara.gopinath@linaro.org>,
	linux-pm@vger.kernel.org,
	Morten Rasmussen <morten.rasmussen@arm.com>,
	Chris Redpath <chris.redpath@arm.com>,
	Valentin Schneider <valentin.schneider@arm.com>,
	"Rafael J . Wysocki" <rjw@rjwysocki.net>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Vincent Guittot <vincent.guittot@linaro.org>,
	Viresh Kumar <viresh.kumar@linaro.org>,
	Todd Kjos <tkjos@google.com>, Joel Fernandes <joelaf@google.com>
Subject: Re: [RFC PATCH 4/6] sched/fair: Introduce an energy estimation helper function
Date: Wed, 21 Mar 2018 15:50:32 +0100	[thread overview]
Message-ID: <20180321145032.GD15165@localhost.localdomain> (raw)
In-Reply-To: <20180321142630.GB2168@queper01-VirtualBox>

On 21/03/18 14:26, Quentin Perret wrote:
> On Wednesday 21 Mar 2018 at 12:39:21 (+0000), Patrick Bellasi wrote:
> > On 20-Mar 09:43, Dietmar Eggemann wrote:

[...]

> > 
> > If that's the case then, in the previous function, you can certainly
> > avoid the initialization of *cs and maybe also add an explicit:
> > 
> >     BUG_ON(em->nb_cap_states == 0);
> > 
> > which helps even just as "in code documentation".
> > 
> > But, I'm not sure if maintainers like BUG_ON in scheduler code :)
> 
> Yes, I'm not sure about the BUG_ON either :). I agree that it would be
> nice to document somewhere that compute_energy() is unsafe to call
> without sched_energy_present. I can simply add a proper doc comment to
> this function actually. Would that work ?

If it is something that must not happen and it is also non recoverable
at runtime, then...

$ git grep BUG_ON -- kernel/sched/ | wc -l
50

:)

  reply	other threads:[~2018-03-21 14:50 UTC|newest]

Thread overview: 54+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-03-20  9:43 [RFC PATCH 0/6] Energy Aware Scheduling Dietmar Eggemann
2018-03-20  9:43 ` [RFC PATCH 1/6] sched/fair: Create util_fits_capacity() Dietmar Eggemann
2018-03-20  9:43 ` [RFC PATCH 2/6] sched: Introduce energy models of CPUs Dietmar Eggemann
2018-03-20  9:52   ` Greg Kroah-Hartman
2018-03-21  0:45     ` Quentin Perret
2018-03-25 13:48     ` Quentin Perret
2018-03-26 22:26       ` Dietmar Eggemann
2018-04-09 12:01   ` Peter Zijlstra
2018-04-09 13:45     ` Quentin Perret
2018-04-09 15:32       ` Peter Zijlstra
2018-04-09 16:42         ` Quentin Perret
2018-04-10  6:55           ` Rafael J. Wysocki
2018-04-10  9:31             ` Quentin Perret
2018-04-10 10:20               ` Rafael J. Wysocki
2018-03-20  9:43 ` [RFC PATCH 3/6] sched: Add over-utilization/tipping point indicator Dietmar Eggemann
2018-04-09  9:40   ` Peter Zijlstra
2018-04-09  9:47     ` Peter Zijlstra
2018-04-09  9:53     ` Dietmar Eggemann
2018-04-09 11:49       ` Peter Zijlstra
2018-03-20  9:43 ` [RFC PATCH 4/6] sched/fair: Introduce an energy estimation helper function Dietmar Eggemann
2018-03-21  9:04   ` Juri Lelli
2018-03-21 12:26     ` Patrick Bellasi
2018-03-21 12:59       ` Juri Lelli
2018-03-21 13:55         ` Quentin Perret
2018-03-21 15:15           ` Juri Lelli
2018-03-21 16:26             ` Morten Rasmussen
2018-03-21 17:02               ` Juri Lelli
2018-03-21 14:02       ` Quentin Perret
2018-03-21 21:15         ` Dietmar Eggemann
2018-03-21 12:39   ` Patrick Bellasi
2018-03-21 14:26     ` Quentin Perret
2018-03-21 14:50       ` Juri Lelli [this message]
2018-03-21 15:54       ` Patrick Bellasi
2018-03-22  5:05         ` Quentin Perret
2018-03-20  9:43 ` [RFC PATCH 5/6] sched/fair: Select an energy-efficient CPU on task wake-up Dietmar Eggemann
2018-03-21 15:35   ` Patrick Bellasi
2018-03-22 20:10     ` Joel Fernandes
2018-03-23 15:47       ` Morten Rasmussen
2018-03-24  1:13         ` Joel Fernandes
2018-03-24  1:34           ` Quentin Perret
2018-03-24  6:06             ` Joel Fernandes
2018-03-24  1:22         ` Quentin Perret
2018-03-25  1:52     ` Quentin Perret
2018-03-22 16:27   ` Joel Fernandes
2018-03-22 18:06     ` Patrick Bellasi
2018-03-22 20:19       ` Joel Fernandes
2018-03-24  1:47         ` Quentin Perret
2018-03-25  0:12           ` Joel Fernandes
2018-03-23 16:00     ` Morten Rasmussen
2018-03-24  0:36       ` Joel Fernandes
2018-03-25  1:38       ` Quentin Perret
2018-03-20  9:43 ` [RFC PATCH 6/6] drivers: base: arch_topology.c: Enable EAS for arm/arm64 platforms Dietmar Eggemann
2018-03-20  9:49   ` Greg Kroah-Hartman
2018-03-20 15:20     ` Dietmar Eggemann

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