From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755261Ab1GCTuM (ORCPT ); Sun, 3 Jul 2011 15:50:12 -0400 Received: from mx2.mail.elte.hu ([157.181.151.9]:36258 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752284Ab1GCTuJ (ORCPT ); Sun, 3 Jul 2011 15:50:09 -0400 Date: Sun, 3 Jul 2011 21:49:49 +0200 From: Ingo Molnar To: Frederic Weisbecker Cc: Michal Marek , Steven Rostedt , LKML , "Paul E. McKenney" , Peter Zijlstra , Randy Dunlap , Thomas Gleixner Subject: Re: [GIT PULL v2] sched: Make sleep inside atomic detection work on !PREEMPT Message-ID: <20110703194949.GC27022@elte.hu> References: <1307712622-11104-1-git-send-email-fweisbec@gmail.com> <20110622224844.GA3290@somewhere> <20110701123629.GA12605@elte.hu> <20110701125644.GD8508@somewhere> <20110701125926.GF12605@elte.hu> <20110701150517.GA24707@elte.hu> <20110701164425.GG8508@somewhere> <20110701172934.GA6240@elte.hu> <20110702165342.GA317@somewhere> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20110702165342.GA317@somewhere> User-Agent: Mutt/1.5.20 (2009-08-17) X-ELTE-SpamScore: -2.0 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-2.0 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.3.1 -2.0 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Frederic Weisbecker wrote: > On Fri, Jul 01, 2011 at 07:29:34PM +0200, Ingo Molnar wrote: > > > > * Frederic Weisbecker wrote: > > > > > On Fri, Jul 01, 2011 at 05:05:17PM +0200, Ingo Molnar wrote: > > > > > > > > -tip testing also found that m32r fails to build: > > > > > > > > /home/mingo/tip/kernel/sched.c: In function 'preempt_schedule': > > > > /home/mingo/tip/kernel/sched.c:4364: error: implicit declaration of function 'add_preempt_count_notrace' > > > > /home/mingo/tip/kernel/sched.c:4366: error: implicit declaration of function 'sub_preempt_count_notrace' > > > > > > > > due to: > > > > > > > > bdd4e85dc36cdbcfc1608a5b2a17c80a9db8986a is the first bad commit > > > > commit bdd4e85dc36cdbcfc1608a5b2a17c80a9db8986a > > > > Author: Frederic Weisbecker > > > > Date: Wed Jun 8 01:13:27 2011 +0200 > > > > > > > > sched: Isolate preempt counting in its own config option > > > > > > > > Thanks, > > > > > > > > Ingo > > > > > > I have no clue how that did happen. > > > > > > Can you send me your config? > > > > Just the m32r defconfig: m32700ut.smp_defconfig. > > > > My guess would be that one of these: > > > > include/linux/bit_spinlock.h | 2 +- > > include/linux/hardirq.h | 4 ++-- > > include/linux/pagemap.h | 4 ++-- > > include/linux/preempt.h | 26 +++++++++++++++++--------- > > include/linux/rcupdate.h | 12 ++++++------ > > include/linux/sched.h | 2 +- > > > > changed/exposed some header dependency quirk on m32r, failing the > > build. Or m32r has some strange .config combo. > > > > Thanks, > > > > Ingo > > That's weird. > > We have this: > > config PREEMPT > bool > select PREEMPT_COUNT > > config PREEMPT_COUNT > bool > > Then I run "make ARCH=m32r defconfig" that has CONFIG_PREEMPT=y > but it doesn't select PREEMPT_COUNT and happily runs to break few > times after. > > Even running make ARCH=m32r oldconfig on the defconfig doesn't fix up > the issue. > > I thought "select" was an unconditional action. What am I missing? > > I'm adding in Cc more people who know better kconfig/kbuild than me. > Every time I finally consider I know well the Kconfig language, I quickly > get caught up by the fate... Architectures have to include kernel/Kconfig.preempt explicitly, like: arch/x86/Kconfig:source "kernel/Kconfig.preempt" m32r does not appear to do this - so it does not know about PREEMPT_COUNT. Thanks, Ingo