lkml.org 
[lkml]   [2014]   [Apr]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 3.11 138/182] hung_task: check the value of "sysctl_hung_task_timeout_sec"
Date
3.11.10.9 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Liu Hua <sdu.liu@huawei.com>

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>
[ luis: backported to 3.11:
- pick hung_task_timeout_secs documentation from commit 270750d
("hung_task: Display every hung task warning") ]
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
---
Documentation/sysctl/kernel.txt | 11 +++++++++++
kernel/sysctl.c | 6 ++++++
2 files changed, 17 insertions(+)

diff --git a/Documentation/sysctl/kernel.txt b/Documentation/sysctl/kernel.txt
index 7ea3a96..1bf2a24 100644
--- a/Documentation/sysctl/kernel.txt
+++ b/Documentation/sysctl/kernel.txt
@@ -286,6 +286,17 @@ Default value is "/sbin/hotplug".

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

+hung_task_timeout_secs:
+
+Check interval. When a task in D state did not get scheduled
+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}.
+
+==============================================================
+
kptr_restrict:

This toggle indicates whether restrictions are placed on
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index f252045..8515e5f 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -143,6 +143,11 @@ 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
@@ -972,6 +977,7 @@ 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",
--
1.9.1


\
 
 \ /
  Last update: 2014-04-24 14:41    [W:0.864 / U:1.412 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site