Messages in this thread Patch in this message | | | From | Liu Hua <> | Subject | [PATCH v3] hung_task : check the value of "sysctl_hung_task_timeout_sec" | Date | Fri, 28 Mar 2014 20:30:08 +0800 |
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As sysctl_hung_task_timeout_sec is unsigned long, when this value is larger then LONG_MAX/HZ, the function schedule_timeout_interruptible in watchdog will return immediately without sleep and with print :
[ 205.452934] schedule_timeout: wrong timeout value ffffffffffffff83
and then the funtion watchdog will call schedule_timeout_interruptible again and again. The screen will be filled with "schedule_timeout: wrong timeout value ffffffffffffff83"
This patch does some check and correction in sysctl, to let the function schedule_timeout_interruptible allways get the valid parameter.
Signed-off-by: Liu Hua <sdu.liu@huawei.com> Tested-by: Satoru Takeuchi <satoru.takeuchi@gmail.com> Cc: stable@vger.kernel.org # 3.4+ --- Documentation/sysctl/kernel.txt | 1 + kernel/sysctl.c | 6 ++++++ 2 files changed, 7 insertions(+)
diff --git a/Documentation/sysctl/kernel.txt b/Documentation/sysctl/kernel.txt index e55124e..855d9b3 100644 --- a/Documentation/sysctl/kernel.txt +++ b/Documentation/sysctl/kernel.txt @@ -317,6 +317,7 @@ for more than this value report a warning. This file shows up if CONFIG_DETECT_HUNG_TASK is enabled. 0: means infinite timeout - no checking done. +Possible values to set are in range {0..LONG_MAX/HZ}. ============================================================== diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 49e13e1..aae21e8 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -144,6 +144,11 @@ static int min_percpu_pagelist_fract = 8; static int ngroups_max = NGROUPS_MAX; static const int cap_last_cap = CAP_LAST_CAP; +/*this is needed for proc_doulongvec_minmax of sysctl_hung_task_timeout_secs */ +#ifdef CONFIG_DETECT_HUNG_TASK +static unsigned long hung_task_timeout_max = (LONG_MAX/HZ); +#endif + #ifdef CONFIG_INOTIFY_USER #include <linux/inotify.h> #endif @@ -995,6 +1000,7 @@ static struct ctl_table kern_table[] = { .maxlen = sizeof(unsigned long), .mode = 0644, .proc_handler = proc_dohung_task_timeout_secs, + .extra2 = &hung_task_timeout_max, }, { .procname = "hung_task_warnings", -- 1.9.0
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