From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752614Ab3INFyE (ORCPT ); Sat, 14 Sep 2013 01:54:04 -0400 Received: from mail-ee0-f44.google.com ([74.125.83.44]:47475 "EHLO mail-ee0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752025Ab3INFyC (ORCPT ); Sat, 14 Sep 2013 01:54:02 -0400 Date: Sat, 14 Sep 2013 07:53:59 +0200 From: Ingo Molnar To: Li Zefan Cc: Andrew Morton , LKML Subject: Re: [PATCH] hung_task: change sysctl_hung_task_check_count to int Message-ID: <20130914055359.GB364@gmail.com> References: <5233CE5E.7040004@huawei.com> <5233CFBF.4000803@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5233CFBF.4000803@huawei.com> 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 * Li Zefan wrote: > Cc: Ingo, as this touched include/linux/sched/. > > On 2013/9/14 10:47, Li Zefan wrote: > > As sysctl_hung_task_check_count is unsigned long, when this value is > > assigned to max_count in check_hung_uninterruptible_tasks(), it's > > truncated to int type. > > > > Therefore if we write 2^32 to sysctl.hung_task_check_count, hung task > > detection will be effectively disabled. > > > > Not a big deal, but still it's better to fix this inconsistency. > > > > Signed-off-by: Li Zefan > > --- > > include/linux/sched/sysctl.h | 2 +- > > kernel/hung_task.c | 2 +- > > kernel/sysctl.c | 4 ++-- > > 3 files changed, 4 insertions(+), 4 deletions(-) > > > > diff --git a/include/linux/sched/sysctl.h b/include/linux/sched/sysctl.h > > index bf8086b..9552afa 100644 > > --- a/include/linux/sched/sysctl.h > > +++ b/include/linux/sched/sysctl.h > > @@ -2,8 +2,8 @@ > > #define _SCHED_SYSCTL_H > > > > #ifdef CONFIG_DETECT_HUNG_TASK > > +extern int sysctl_hung_task_check_count; > > extern unsigned int sysctl_hung_task_panic; > > -extern unsigned long sysctl_hung_task_check_count; > > extern unsigned long sysctl_hung_task_timeout_secs; extern unsigned > > long sysctl_hung_task_warnings; extern int > > proc_dohung_task_timeout_secs(struct ctl_table *table, int write, Looks good, but I suppose most of the unsigned longs above ought to be downgraded to int as well? Acked-by: Ingo Molnar Thanks, Ingo