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| author | Liu Hua <sdu.liu@huawei.com> | 2014-04-07 15:38:57 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-05-06 07:59:35 -0700 |
| commit | dfe468daba552b4d474db75ff54562691150bb78 (patch) | |
| tree | 7248942c8852c6c37297fd3b2dcfd43fa2d310a3 /kernel/sysctl.c | |
| parent | 05b36270c305cf8e4d0d2b29b89c42f7ecd77d1c (diff) | |
| download | lwn-dfe468daba552b4d474db75ff54562691150bb78.tar.gz lwn-dfe468daba552b4d474db75ff54562691150bb78.zip | |
hung_task: check the value of "sysctl_hung_task_timeout_sec"
commit 80df28476505ed4e6701c3448c63c9229a50c655 upstream.
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 :
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>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'kernel/sysctl.c')
| -rw-r--r-- | kernel/sysctl.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 49e13e1f8fe6..aae21e842918 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", |