Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S937406AbdCJN2f (ORCPT ); Fri, 10 Mar 2017 08:28:35 -0500 Received: from mail-it0-f67.google.com ([209.85.214.67]:35853 "EHLO mail-it0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S937324AbdCJN23 (ORCPT ); Fri, 10 Mar 2017 08:28:29 -0500 MIME-Version: 1.0 In-Reply-To: <20170310131750.GB11875@amd> References: <20170307182855.262ezbon2pm67qfd@treble> <20170308173703.2h57rsltma3smbcm@treble> <20170308212253.GA29562@amd> <20170309105655.GA29554@amd> <20170310131750.GB11875@amd> From: Geert Uytterhoeven Date: Fri, 10 Mar 2017 14:28:21 +0100 X-Google-Sender-Auth: EWUSMMXY1bqbvCoAgv6DmrU8La0 Message-ID: Subject: Re: Compiling kernels faster (was Re: v4.10: kernel stack frame pointer .. has bad value (null)) To: Pavel Machek Cc: Linus Torvalds , Josh Poimboeuf , Andy Lutomirski , kernel list , Ingo Molnar , Andrew Lutomirski , Borislav Petkov , Brian Gerst , Denys Vlasenko , Peter Anvin , Peter Zijlstra , Thomas Gleixner 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-Length: 2033 Lines: 52 Hi Pavel, On Fri, Mar 10, 2017 at 2:17 PM, Pavel Machek wrote: > On Thu 2017-03-09 13:16:09, Geert Uytterhoeven wrote: >> On Thu, Mar 9, 2017 at 11:56 AM, Pavel Machek wrote: >> > On Thu 2017-03-09 10:38:46, Geert Uytterhoeven wrote: >> >> I hope you do use ccache or distcc? >> > >> > I tried to use distcc before, but it was rather hard to maintain. No >> > ccache here. Hmm. I guess ccache really makes sense for bisect. >> >> Yes it does. So if you're not using it yet, do the below, today, not tomorrow. >> >> If your distro supports it, prepend /usr/lib/ccache/ to your $PATH. >> Create symlinks from the names of your favorite cross-compilers >> to /usr/bin/ccache, and make sure they are early in your $PATH. >> >> That's it! Enjoy! > > Hmm. Installed, and seems to work. OTOH, compilation now seems to > produce 2-3MB/sec writing on spinning rust, and CPUs are no longer > fully loaded. (make -j 7 on 2 core HT machine). Any io load sends the > CPU utilization to cca 50% range... Compilation goes up from 9:13 to > 11:40... to 23 minutes depending on situation. I guess it is still I guess that was the first build, with a clean cache? Now run "make clean", and try again ;-) BTW, I tend not to do -j beyond the number of cores/threads (i.e. -j 8 on the i7-4770), unless you just want to compile, and not enjoy other interactive work ;-) > worth it for the bisect, but it looks like ccache really needs an ssd. Adding an SSD never hurts. Although I have been a happy user of ccache since long before I got an SSD. > Hmm. And killing chromium matters a lot for a compile time. I hate > modern web :-(. Adding (freeing) RAM also never hurts ;-) Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds