From: Peter Zijlstra <peterz@infradead.org>
To: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: linux-kernel@vger.kernel.org, mingo@elte.hu, rjw@rjwysocki.net,
nicolas.pitre@linaro.org, linux-pm@vger.kernel.org,
alex.shi@linaro.org, vincent.guittot@linaro.org,
morten.rasmussen@arm.com
Subject: Re: [RFC PATCHC 2/3] idle: store the idle state the cpu is
Date: Tue, 15 Apr 2014 14:44:37 +0200 [thread overview]
Message-ID: <20140415124437.GO13658@twins.programming.kicks-ass.net> (raw)
In-Reply-To: <20140415124330.GK11182@twins.programming.kicks-ass.net>
On Tue, Apr 15, 2014 at 02:43:30PM +0200, Peter Zijlstra wrote:
> On Fri, Mar 28, 2014 at 01:29:55PM +0100, Daniel Lezcano wrote:
> > @@ -143,6 +145,10 @@ static int cpuidle_idle_call(void)
> > if (!ret) {
> > trace_cpu_idle_rcuidle(next_state, dev->cpu);
> >
> > + *power = &drv->states[next_state].power;
> > +
> > + wmb();
> > +
>
> I very much suspect you meant: smp_wmb(), as I don't see the hardware
> reading that pointer, therefore UP wouldn't care. Also, any and all
> barriers should come with a comment that describes the data ordering and
> points to the matchin barriers.
Furthermore, this patch fails to describe the life-time rules of the
object placed there. Can the objected pointed to ever disappear?
next prev parent reply other threads:[~2014-04-15 12:44 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-03-28 12:29 [RFC PATCHC 0/3] sched/idle : find the idlest cpu with cpuidle info Daniel Lezcano
2014-03-28 12:29 ` [RFC PATCHC 1/3] cpuidle: encapsulate power info in a separate structure Daniel Lezcano
2014-03-28 18:17 ` Nicolas Pitre
2014-03-28 20:42 ` Daniel Lezcano
2014-03-29 0:00 ` Nicolas Pitre
2014-03-28 12:29 ` [RFC PATCHC 2/3] idle: store the idle state the cpu is Daniel Lezcano
2014-04-15 12:43 ` Peter Zijlstra
2014-04-15 12:44 ` Peter Zijlstra [this message]
2014-04-15 14:17 ` Daniel Lezcano
2014-04-15 14:33 ` Peter Zijlstra
2014-04-15 14:39 ` Daniel Lezcano
2014-03-28 12:29 ` [RFC PATCHC 3/3] sched/fair: use the idle state info to choose the idlest cpu Daniel Lezcano
2014-04-02 3:05 ` Nicolas Pitre
2014-04-04 11:57 ` Rafael J. Wysocki
2014-04-04 16:56 ` Nicolas Pitre
2014-04-05 2:01 ` Rafael J. Wysocki
2014-04-17 13:53 ` Daniel Lezcano
2014-04-17 14:47 ` Peter Zijlstra
2014-04-17 15:03 ` Daniel Lezcano
2014-04-18 8:09 ` Ingo Molnar
2014-04-18 8:36 ` Daniel Lezcano
2014-04-17 15:53 ` Nicolas Pitre
2014-04-17 16:05 ` Daniel Lezcano
2014-04-17 16:21 ` Nicolas Pitre
2014-04-18 9:38 ` Peter Zijlstra
2014-04-18 12:13 ` Daniel Lezcano
2014-04-18 12:53 ` Peter Zijlstra
2014-04-18 13:04 ` Daniel Lezcano
2014-04-18 16:00 ` Nicolas Pitre
2014-04-15 13:03 ` Peter Zijlstra
2014-03-31 13:52 ` [RFC PATCHC 0/3] sched/idle : find the idlest cpu with cpuidle info Vincent Guittot
2014-03-31 15:55 ` Daniel Lezcano
2014-04-01 7:16 ` Vincent Guittot
2014-04-01 7:43 ` Daniel Lezcano
2014-04-01 9:05 ` Vincent Guittot
2014-04-15 13:13 ` Peter Zijlstra
2014-04-01 23:01 ` Rafael J. Wysocki
2014-04-02 3:14 ` Nicolas Pitre
2014-04-04 11:43 ` Rafael J. Wysocki
2014-04-15 13:17 ` Peter Zijlstra
2014-04-15 13:25 ` Peter Zijlstra
2014-04-15 15:27 ` Nicolas Pitre
2014-04-15 15:33 ` Rafael J. Wysocki
2014-04-02 8:26 ` Daniel Lezcano
2014-04-04 11:23 ` Rafael J. Wysocki
2014-04-04 6:29 ` Len Brown
2014-04-04 8:16 ` Daniel Lezcano
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