From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753807AbZGXSF1 (ORCPT ); Fri, 24 Jul 2009 14:05:27 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753723AbZGXSF0 (ORCPT ); Fri, 24 Jul 2009 14:05:26 -0400 Received: from ey-out-2122.google.com ([74.125.78.24]:40602 "EHLO ey-out-2122.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753708AbZGXSFZ (ORCPT ); Fri, 24 Jul 2009 14:05:25 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=from:to:cc:subject:date:message-id:x-mailer; b=YGZ4S6FQeOZ0OflxOm9jKWiq+WAzDzuFF1+5LaXBgNBzJ72Rc8qx0dVp3PeNcgdiPH CreGEGezcS9N92DeQ9FhWLfhYxb5dVq8OiYY2c6LphwTcm7HPU8krG0NsFqdQzZkVOyo zL3M7ZhW2wpoWbei1i1+NFT2AYgyEwyL25DS4= From: Frederic Weisbecker To: Ingo Molnar Cc: LKML , Frederic Weisbecker , Li Zefan , Peter Zijlstra Subject: [PATCH] sched: Fix cond_resched_lock() in !CONFIG_PREEMPT Date: Fri, 24 Jul 2009 20:05:23 +0200 Message-Id: <1248458723-12146-1-git-send-email-fweisbec@gmail.com> X-Mailer: git-send-email 1.6.2.3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The might_sleep() test inside cond_resched_lock() assumes the spinlock is held and then preemption is disabled. This is true with CONFIG_PREEMPT but the preempt_count() doesn't change otherwise. Check by starting from the appropriate preempt offset depending on the config. Reported-by: Li Zefan Signed-off-by: Frederic Weisbecker Cc: Peter Zijlstra --- include/linux/sched.h | 8 +++++++- 1 files changed, 7 insertions(+), 1 deletions(-) diff --git a/include/linux/sched.h b/include/linux/sched.h index cb070dc..2c35bc2 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -2294,8 +2294,14 @@ extern int _cond_resched(void); extern int __cond_resched_lock(spinlock_t *lock); +#ifdef CONFIG_PREEMPT +#define PREEMPT_LOCK_OFFSET PREEMPT_OFFSET +#else +#define PREEMPT_LOCK_OFFSET 0 +#endif + #define cond_resched_lock(lock) ({ \ - __might_sleep(__FILE__, __LINE__, PREEMPT_OFFSET); \ + __might_sleep(__FILE__, __LINE__, PREEMPT_LOCK_OFFSET); \ __cond_resched_lock(lock); \ }) -- 1.6.2.3