From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756088Ab2CXKcj (ORCPT ); Sat, 24 Mar 2012 06:32:39 -0400 Received: from mail-bk0-f46.google.com ([209.85.214.46]:54728 "EHLO mail-bk0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754749Ab2CXKch (ORCPT ); Sat, 24 Mar 2012 06:32:37 -0400 Date: Sat, 24 Mar 2012 14:31:27 +0400 From: Anton Vorontsov To: Andrew Morton , Oleg Nesterov Cc: Russell King , Mike Frysinger , Benjamin Herrenschmidt , Richard Weinberger , Paul Mundt , Peter Zijlstra , KOSAKI Motohiro , John Stultz , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, uclinux-dist-devel@blackfin.uclinux.org, linuxppc-dev@lists.ozlabs.org, linux-sh@vger.kernel.org, user-mode-linux-devel@lists.sourceforge.net, linux-mm@kvack.org Subject: [PATCH 10/10] oom: Make find_lock_task_mm() sparse-aware Message-ID: <20120324103127.GJ29067@lizard> References: <20120324102609.GA28356@lizard> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20120324102609.GA28356@lizard> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This is needed so that callers would not get 'context imbalance' warnings from the sparse tool. As a side effect, this patch fixes the following sparse warnings: CHECK mm/oom_kill.c mm/oom_kill.c:201:28: warning: context imbalance in 'oom_badness' - unexpected unlock include/linux/rcupdate.h:249:30: warning: context imbalance in 'dump_tasks' - unexpected unlock mm/oom_kill.c:453:9: warning: context imbalance in 'oom_kill_task' - unexpected unlock CHECK mm/memcontrol.c ... mm/memcontrol.c:1130:17: warning: context imbalance in 'task_in_mem_cgroup' - unexpected unlock p.s. I know Peter Zijlstra detest the __cond_lock() stuff, but untill we have anything better in sparse, let's use it. This particular patch helped me to detect one bug that I myself made during task->mm fixup series. So, it is useful. Signed-off-by: Anton Vorontsov Acked-by: KOSAKI Motohiro --- include/linux/oom.h | 12 +++++++++++- mm/oom_kill.c | 2 +- 2 files changed, 12 insertions(+), 2 deletions(-) diff --git a/include/linux/oom.h b/include/linux/oom.h index 552fba9..26cf628 100644 --- a/include/linux/oom.h +++ b/include/linux/oom.h @@ -21,6 +21,7 @@ #ifdef __KERNEL__ +#include #include #include #include @@ -65,7 +66,16 @@ static inline void oom_killer_enable(void) oom_killer_disabled = false; } -extern struct task_struct *find_lock_task_mm(struct task_struct *p); +extern struct task_struct *__find_lock_task_mm(struct task_struct *p); + +static inline struct task_struct *find_lock_task_mm(struct task_struct *p) +{ + struct task_struct *ret; + + ret = __find_lock_task_mm(p); + (void)__cond_lock(&ret->alloc_lock, ret); + return ret; +} /* sysctls */ extern int sysctl_oom_dump_tasks; diff --git a/mm/oom_kill.c b/mm/oom_kill.c index 2958fd8..0ebb383 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -136,7 +136,7 @@ static bool has_intersects_mems_allowed(struct task_struct *tsk, * pointer. Return p, or any of its subthreads with a valid ->mm, with * task_lock() held. */ -struct task_struct *find_lock_task_mm(struct task_struct *p) +struct task_struct *__find_lock_task_mm(struct task_struct *p) { struct task_struct *t = p; -- 1.7.9.2