From: Daniel Lezcano <daniel.lezcano@linaro.org>
To: Peter Zijlstra <peterz@infradead.org>
Cc: rjw@rjwysocki.net, nicolas.pitre@linaro.org,
linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org,
linaro-kernel@lists.linaro.org
Subject: Re: [PATCH 3/5] cpuidle: idle: menu: Don't reflect when a state selection failed
Date: Fri, 24 Oct 2014 15:32:52 +0200 [thread overview]
Message-ID: <544A5504.2090706@linaro.org> (raw)
In-Reply-To: <20141024132428.GJ12706@worktop.programming.kicks-ass.net>
On 10/24/2014 03:24 PM, Peter Zijlstra wrote:
> On Mon, Oct 20, 2014 at 06:25:41PM +0200, Daniel Lezcano wrote:
>> - if (index > 0)
>> - if (index >= 0)
>
> That's not the same condition.
Yes and it is wrong. That is the result of the
CPUIDLE_DRIVER_STATE_START dance.
The ladder governor is avoiding to use the POLL state as it was running
on x86. But on, eg. ARM, we will never reflect the state 0 because
CPUIDLE_DRIVER_STATE_START is equal to zero for all non-x86 platform.
If I am not wrong the ladder select function will never choose the state
0 for x86, so it will never reflect the state 0 (after applying the
patch 1/5). For the other arch it will reflect the state 0 as it should.
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next prev parent reply other threads:[~2014-10-24 13:32 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-10-20 16:25 [PATCH 1/5] sched: idle: cpuidle: Check the latency req before idle Daniel Lezcano
2014-10-20 16:25 ` [PATCH 2/5] sched: idle: Get the next timer event and pass it the cpuidle framework Daniel Lezcano
2014-10-22 20:38 ` Nicolas Pitre
2014-10-28 1:53 ` Len Brown
2014-10-28 6:40 ` Preeti Murthy
2014-10-28 18:02 ` Daniel Lezcano
2014-10-20 16:25 ` [PATCH 3/5] cpuidle: idle: menu: Don't reflect when a state selection failed Daniel Lezcano
2014-10-22 20:41 ` Nicolas Pitre
2014-10-24 13:24 ` Peter Zijlstra
2014-10-24 13:32 ` Daniel Lezcano [this message]
2014-10-24 13:38 ` Peter Zijlstra
2014-10-24 13:43 ` Daniel Lezcano
2014-10-24 13:56 ` Peter Zijlstra
2014-10-20 16:25 ` [PATCH 4/5] cpuidle: menu: Fix the get_typical_interval Daniel Lezcano
2014-10-20 16:25 ` [PATCH 5/5] cpuidle: menu: Move the update function before its declaration Daniel Lezcano
2014-10-22 20:30 ` [PATCH 1/5] sched: idle: cpuidle: Check the latency req before idle Nicolas Pitre
2014-10-27 22:58 ` Rafael J. Wysocki
2014-10-28 8:30 ` Peter Zijlstra
2014-10-28 1:49 ` Len Brown
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