3.11.10.9 -stable review patch. If anyone has any objections, please let me
know.
------------------
From: Liu Hua <sdu....@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....@huawei.com>
Tested-by: Satoru Takeuchi <satoru.takeu...@gmail.com>
Signed-off-by: Andrew Morton <a...@linux-foundation.org>
Signed-off-by: Linus Torvalds <torva...@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.henriq...@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
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