Re: [patch v4 08/18] Revert "sched: Introduce temporaryFAIR_GROUP_SCHED dependency for load-tracking"

From: Paul Turner
Date: Wed Feb 13 2013 - 10:46:37 EST


On Wed, Feb 13, 2013 at 7:23 AM, Alex Shi <alex.shi@xxxxxxxxx> wrote:
> On 02/12/2013 06:27 PM, Peter Zijlstra wrote:
>> On Thu, 2013-01-24 at 11:06 +0800, Alex Shi wrote:
>>> Remove CONFIG_FAIR_GROUP_SCHED that covers the runnable info, then
>>> we can use runnable load variables.
>>>
>> It would be nice if we could quantify the performance hit of doing so.
>> Haven't yet looked at later patches to see if we remove anything to
>> off-set this.
>>
>
> In our rough testing, no much clear performance changes.
>

I'd personally like this to go with a series that actually does
something with it.

There's been a few proposals floating around on _how_ to do this; but
the challenge is in getting it stable enough that all of the wake-up
balancing does not totally perforate your stability gains into the
noise. select_idle_sibling really is your nemesis here.

It's a small enough patch that it can go at the head of any such
series (and indeed; it was originally structured to make such a patch
rather explicit.)

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