hung_task: check the value of "sysctl_hung_task_timeout_sec" (80df2847) · Commits · 戴 / test

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>

Documentation/sysctl/kernel.txt

+1 −0

Original line number	Diff line number	Diff line
		@@ -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}.

		==============================================================

kernel/sysctl.c

+6 −0

Original line number	Diff line number	Diff line
		@@ -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",

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