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

From: JÃrg Otte
Date: Wed Oct 19 2016 - 12:59:41 EST


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.

JÃrg