From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756382Ab3INCyC (ORCPT ); Fri, 13 Sep 2013 22:54:02 -0400 Received: from szxga02-in.huawei.com ([119.145.14.65]:25312 "EHLO szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756004Ab3INCyB (ORCPT ); Fri, 13 Sep 2013 22:54:01 -0400 Message-ID: <5233CFBF.4000803@huawei.com> Date: Sat, 14 Sep 2013 10:53:51 +0800 From: Li Zefan User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:17.0) Gecko/20130801 Thunderbird/17.0.8 MIME-Version: 1.0 To: Andrew Morton CC: LKML , Ingo Molnar Subject: Re: [PATCH] hung_task: change sysctl_hung_task_check_count to int References: <5233CE5E.7040004@huawei.com> In-Reply-To: <5233CE5E.7040004@huawei.com> Content-Type: text/plain; charset="GB2312" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.135.68.215] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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, > diff --git a/kernel/hung_task.c b/kernel/hung_task.c > index 6df6149..b5a5d42 100644 > --- a/kernel/hung_task.c > +++ b/kernel/hung_task.c > @@ -19,7 +19,7 @@ > /* > * The number of tasks checked: > */ > -unsigned long __read_mostly sysctl_hung_task_check_count = PID_MAX_LIMIT; > +int __read_mostly sysctl_hung_task_check_count = PID_MAX_LIMIT; > > /* > * Limit number of tasks checked in a batch. > diff --git a/kernel/sysctl.c b/kernel/sysctl.c > index 07f6fc4..5e5cc21 100644 > --- a/kernel/sysctl.c > +++ b/kernel/sysctl.c > @@ -962,9 +962,9 @@ static struct ctl_table kern_table[] = { > { > .procname = "hung_task_check_count", > .data = &sysctl_hung_task_check_count, > - .maxlen = sizeof(unsigned long), > + .maxlen = sizeof(int), > .mode = 0644, > - .proc_handler = proc_doulongvec_minmax, > + .proc_handler = proc_dointvec_minmax, > }, > { > .procname = "hung_task_timeout_secs", >