On 14-03-06 02:19 AM, Liu hua wrote:
> As sysctl_hung_task_timeout_sec is unsigned long, when this value is
> larger then LONG_MAX, the function schedule_timeout_interruptible in
> watchdog will return immediately without sleep :
>
> for example (in x86_64 platform):
>
> linux# echo 0xFFFFFFFFFFFFFFFF > /proc/sys/kernel/hung_task_timeout_secs
>
> [ 66.798350] schedule_timeout: wrong timeout value ffffffffffffff06
> [ 66.800064] schedule_timeout: wrong timeout value ffffffffffffff06
> [ 66.801774] schedule_timeout: wrong timeout value ffffffffffffff06
> [ 66.803488] schedule_timeout: wrong timeout value ffffffffffffff06
> [ 66.805225] schedule_timeout: wrong timeout value ffffffffffffff06
>
> The screen was filled with "schedule_timeout: wrong timeout value
> ffffffffffffff06" and the system stalled.
>
> So I do some check and correction in timeout_jiffies, to let the function
> schedule_timeout_interruptible allways get the valid parameter.
>
> Signed-off-by: Liu Hua <sdu....@huawei.com>
> ---
> kernel/hung_task.c | 11 ++++++++++-
> 1 file changed, 10 insertions(+), 1 deletion(-)
>
> diff --git a/kernel/hung_task.c b/kernel/hung_task.c
> index 06bb141..ef96650 100644
> --- a/kernel/hung_task.c
> +++ b/kernel/hung_task.c
> @@ -186,7 +186,16 @@ static void check_hung_uninterruptible_tasks(unsigned
> long timeout)
> static unsigned long timeout_jiffies(unsigned long timeout)
> {
> /* timeout of 0 will disable the watchdog */
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
You are breaking the above functionality/feature by declaring
zero invalid.
Paul.
--
> - return timeout ? timeout * HZ : MAX_SCHEDULE_TIMEOUT;
> + if ((timeout == 0) || (timeout > MAX_SCHEDULE_TIMEOUT)) {
> + pr_err("%s : wrong timeout value %lx\n",
> + __func__, timeout);
> + pr_err("Timeout value is set to MAX_SCHEDULE_TIMEOUT(%lx)
> now.\n",
> + MAX_SCHEDULE_TIMEOUT);
> + return MAX_SCHEDULE_TIMEOUT;
> + }
> +
> + return (timeout * HZ) < MAX_SCHEDULE_TIMEOUT ?
> + timeout * HZ : MAX_SCHEDULE_TIMEOUT;
> }
>
> /*
>
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