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authorLiu Hua <sdu.liu@huawei.com>2014-04-07 15:38:57 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2014-04-07 16:36:07 -0700
commit80df28476505ed4e6701c3448c63c9229a50c655 (patch)
treec8c8a1987998a08cf6e74c34b474d8cf705e4114
parent2aaf308b95b24649a6dcfed89cd956e972089b2a (diff)
hung_task: check the value of "sysctl_hung_task_timeout_sec"
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> Cc: <stable@vger.kernel.org> [3.4+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--Documentation/sysctl/kernel.txt1
-rw-r--r--kernel/sysctl.c6
2 files changed, 7 insertions, 0 deletions
diff --git a/Documentation/sysctl/kernel.txt b/Documentation/sysctl/kernel.txt
index 271a09db6629..9886c3d57fc2 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 5c14b547882e..74f5b580fe34 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -141,6 +141,11 @@ 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
@@ -985,6 +990,7 @@ 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",