Re: [4.9-rc1] Build-time 2x slower

From: Sedat Dilek
Date: Thu Oct 20 2016 - 03:28:41 EST


On Wed, Oct 19, 2016 at 6:59 PM, JÃrg Otte <jrg.otte@xxxxxxxxx> wrote:
> 2016-10-19 17:29 GMT+02:00 Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>:
>> On Wed, Oct 19, 2016 at 4:07 AM, JÃrg Otte <jrg.otte@xxxxxxxxx> wrote:
>>>
>>> Additional info: I usally use schedutil governor.
>>> If I switch to performance governor problems go away.
>>> Maybe a cpufreq problem?
>>
>> Oh, I completely misread the original bug report, and then didn't read
>> your confirmation email right.
>>
>> I thought you had a slower build of the different kernels (when
>> building on the same kernel), and that the _build_ itself had slowed
>> down for some reason. But you're actually saying that doing the _same_
>> build actually takes longer when running on 4.9-rc1.
>
> Exactly!
>
> Btw: ondemand governor is also good.
>
>> There are a few small cpufreq changes there in between commit
>> 29fbff8698fc (that you reported was fine - please tell me I got _that_
>> right, at least?) and 4.9-rc1.
>
> Perfect! That's what I mean.
>
>> Adding Rafael to the cc.
>>
>> That said, none of them look all that likely to me. It *would* be good
>> if you could bisect it a bit (perhaps not fully, but a couple of
>> bisection steps to narrow down what area it is).
>
> I try that tomorrow.
>

I switched over to ***schedutil*** as default-cpufreq-governor with
v4.8 in my init-scripts.
Didn't try any other cpufreq-governor and had no time to play more
with this issue.

- Sedat -