From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752381AbZGTGwA (ORCPT ); Mon, 20 Jul 2009 02:52:00 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751854AbZGTGv5 (ORCPT ); Mon, 20 Jul 2009 02:51:57 -0400 Received: from cn.fujitsu.com ([222.73.24.84]:63779 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1751020AbZGTGv4 (ORCPT ); Mon, 20 Jul 2009 02:51:56 -0400 Message-ID: <4A6413AB.2050807@cn.fujitsu.com> Date: Mon, 20 Jul 2009 14:50:19 +0800 From: Li Zefan User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.1b3pre) Gecko/20090513 Fedora/3.0-2.3.beta2.fc11 Thunderbird/3.0b2 MIME-Version: 1.0 To: fweisbec@gmail.com CC: hpa@zytor.com, linux-kernel@vger.kernel.org, a.p.zijlstra@chello.nl, tglx@linutronix.de, mingo@elte.hu, linux-tip-commits@vger.kernel.org Subject: Re: [tip:sched/core] sched: Pull up the might_sleep() check into cond_resched() References: <1247725694-6082-6-git-send-email-fweisbec@gmail.com> In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > Commit-ID: 613afbf83298efaead05ebcac23d2285609d7160 > Gitweb: http://git.kernel.org/tip/613afbf83298efaead05ebcac23d2285609d7160 > Author: Frederic Weisbecker > AuthorDate: Thu, 16 Jul 2009 15:44:29 +0200 > Committer: Ingo Molnar > CommitDate: Sat, 18 Jul 2009 15:51:44 +0200 > > sched: Pull up the might_sleep() check into cond_resched() > > might_sleep() is called late-ish in cond_resched(), after the > need_resched()/preempt enabled/system running tests are > checked. > > It's better to check the sleeps while atomic earlier and not > depend on some environment datas that reduce the chances to > detect a problem. > > Also define cond_resched_*() helpers as macros, so that the > FILE/LINE reported in the sleeping while atomic warning > displays the real origin and not sched.h > I guess it's this patch that causes lots of "BUG" BUG: sleeping function called from invalid context at fs/jbd/commit.c:902 in_atomic(): 0, irqs_disabled(): 0, pid: 64, name: kjournald INFO: lockdep is turned off. Pid: 64, comm: kjournald Tainted: GF 2.6.31-rc3-tip #15 Call Trace: [] __might_sleep+0xda/0xdf [] journal_commit_transaction+0xb03/0xc5f [] ? try_to_del_timer_sync+0x48/0x4f [] kjournald+0xcf/0x1fe [] ? autoremove_wake_function+0x0/0x34 [] ? kjournald+0x0/0x1fe [] kthread+0x6b/0x70 [] ? kthread+0x0/0x70 [] kernel_thread_helper+0x7/0x10 BUG: sleeping function called from invalid context at fs/dcache.c:512 in_atomic(): 0, irqs_disabled(): 0, pid: 2005, name: bash INFO: lockdep is turned off. Pid: 2005, comm: bash Tainted: GF 2.6.31-rc3-tip #15 Call Trace: [] __might_sleep+0xda/0xdf [] __shrink_dcache_sb+0x208/0x27a [] shrink_dcache_parent+0x2c/0xcf [] proc_flush_task+0xa7/0x194 [] release_task+0x29/0x3b4 [] wait_consider_task+0x702/0xa91 [] do_wait+0xde/0x276 [] ? default_wake_function+0x0/0x12 [] sys_wait4+0x8d/0xa6 [] ? might_fault+0x85/0x87 [] sys_waitpid+0x18/0x1a [] sysenter_do_call+0x12/0x36 ... ... > Changes in v2: > > - Call __might_sleep() directly instead of might_sleep() which > may call cond_resched() > > - Turn cond_resched() into a macro so that the file:line > couple reported refers to the caller of cond_resched() and > not __cond_resched() itself. > > Changes in v3: > > - Also propagate this __might_sleep() pull up to > cond_resched_lock() and cond_resched_softirq() > > Signed-off-by: Frederic Weisbecker > Signed-off-by: Peter Zijlstra > LKML-Reference: <1247725694-6082-6-git-send-email-fweisbec@gmail.com> > Signed-off-by: Ingo Molnar