lkml.org 
[lkml]   [2014]   [Oct]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 3/5] cpuidle: idle: menu: Don't reflect when a state selection failed
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.

--
<http://www.linaro.org/> Linaro.org │ Open source software for ARM SoCs

Follow Linaro: <http://www.facebook.com/pages/Linaro> Facebook |
<http://twitter.com/#!/linaroorg> Twitter |
<http://www.linaro.org/linaro-blog/> Blog

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2014-10-24 16:01    [W:0.966 / U:0.344 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site