Re: [PATCH] hung_task: change sysctl_hung_task_check_count to int

Ingo Molnar
2013-09-14T05:54:04Z

* Li Zefan <lizefan@huawei.com> 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 <lizefan@huawei.com>
> > ---
> > 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 <mingo@kernel.org>

Thanks,

Ingo