Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S938626AbcJTOUs (ORCPT ); Thu, 20 Oct 2016 10:20:48 -0400 Received: from mail-vk0-f66.google.com ([209.85.213.66]:33254 "EHLO mail-vk0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934018AbcJTOUr (ORCPT ); Thu, 20 Oct 2016 10:20:47 -0400 MIME-Version: 1.0 Reply-To: sedat.dilek@gmail.com In-Reply-To: <2813073.ZhfuKSkB6i@vostro.rjw.lan> References: <2198826.9suuMCzPZN@vostro.rjw.lan> <2813073.ZhfuKSkB6i@vostro.rjw.lan> From: Sedat Dilek Date: Thu, 20 Oct 2016 16:20:44 +0200 Message-ID: Subject: Re: [4.9-rc1] Build-time 2x slower To: "Rafael J. Wysocki" Cc: =?UTF-8?Q?J=C3=B6rg_Otte?= , Linus Torvalds , "Rafael J. Wysocki" , Michal Marek , Ming Lei , LKML Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by mail.home.local id u9KEL6LA026216 Content-Length: 3153 Lines: 77 On Thu, Oct 20, 2016 at 1:15 PM, Rafael J. Wysocki wrote: > On Thursday, October 20, 2016 09:41:34 AM Sedat Dilek wrote: >> On Wed, Oct 19, 2016 at 10:55 PM, Rafael J. Wysocki wrote: >> > On Wednesday, October 19, 2016 06:59:35 PM Jörg Otte wrote: >> >> 2016-10-19 17:29 GMT+02:00 Linus Torvalds : >> >> > On Wed, Oct 19, 2016 at 4:07 AM, Jörg Otte 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. >> > >> > Well, please try commit ef98988ba369 (Merge tag 'pm-extra-4.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm) which is the >> > merge introducing the late cpufreq changes. If the issue is there, please >> > try to revert commit 899bb6642f2a (cpufreq: skip invalid entries when searching >> > the frequency) which is the only cpufreq one that may matter for the schedutil >> > governor (and I have one fix for that commit queued up already). >> > >> >> Is "cpufreq: fix overflow in cpufreq_table_find_index_dl()" the fix >> you are speaking of? >> >> Fixes: 899bb6642f2a (cpufreq: skip invalid entries when searching the frequency) > > Yes. > >> If yes, can you add a hint in the commit message describing the impact >> like here a slow-down of building a linux-kernel. >> With a reference to this ML-thread? > > I will if that turns out to be the case. > I have tried the revert and the patch from Sergey Senozhatsk pending in linux-pm.git#linux-next. Both fixes the issue for me. Feel free to give appropriate credits and many thanks to Jörg. I tried 'make -j3' in my last build and it was approx. 5mins faster in my customized setup. Will switch back to 2 parallel-make-jobs - it's safer for me. Can you explain why this issue was not seen when building under Linux v4.8.x? [1] says... Cc: 4.8+ # 4.8+ Thanks. - sed@ - [1] http://git.kernel.org/cgit/linux/kernel/git/rafael/linux-pm.git/commit/?h=linux-next&id=f7a7a80ae30521b65a6dfc98df45d3ec9e238d73