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

From: Linus Torvalds
Date: Wed Oct 19 2016 - 11:29:23 EST

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.

My bad.

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. 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).