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-rw-r--r--Documentation/sysctl/kernel.txt15
-rw-r--r--include/linux/sched.h1
-rw-r--r--include/linux/sched/sysctl.h1
-rw-r--r--kernel/fork.c1
-rw-r--r--kernel/hung_task.c15
-rw-r--r--kernel/sysctl.c13
6 files changed, 43 insertions, 3 deletions
diff --git a/Documentation/sysctl/kernel.txt b/Documentation/sysctl/kernel.txt
index 59585030cbaf..9d38e75b19a0 100644
--- a/Documentation/sysctl/kernel.txt
+++ b/Documentation/sysctl/kernel.txt
@@ -38,6 +38,7 @@ show up in /proc/sys/kernel:
- hung_task_panic
- hung_task_check_count
- hung_task_timeout_secs
+- hung_task_check_interval_secs
- hung_task_warnings
- hyperv_record_panic_msg
- kexec_load_disabled
@@ -355,7 +356,7 @@ This file shows up if CONFIG_DETECT_HUNG_TASK is enabled.
hung_task_timeout_secs:
-Check interval. When a task in D state did not get scheduled
+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.
@@ -364,6 +365,18 @@ Possible values to set are in range {0..LONG_MAX/HZ}.
==============================================================
+hung_task_check_interval_secs:
+
+Hung task check interval. If hung task checking is enabled
+(see hung_task_timeout_secs), the check is done every
+hung_task_check_interval_secs seconds.
+This file shows up if CONFIG_DETECT_HUNG_TASK is enabled.
+
+0 (default): means use hung_task_timeout_secs as checking interval.
+Possible values to set are in range {0..LONG_MAX/HZ}.
+
+==============================================================
+
hung_task_warnings:
The maximum number of warnings to report. During a check interval
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 789923fbee3a..58eb3a2bc695 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -853,6 +853,7 @@ struct task_struct {
#endif
#ifdef CONFIG_DETECT_HUNG_TASK
unsigned long last_switch_count;
+ unsigned long last_switch_time;
#endif
/* Filesystem information: */
struct fs_struct *fs;
diff --git a/include/linux/sched/sysctl.h b/include/linux/sched/sysctl.h
index 913488d828cb..a9c32daeb9d8 100644
--- a/include/linux/sched/sysctl.h
+++ b/include/linux/sched/sysctl.h
@@ -10,6 +10,7 @@ struct ctl_table;
extern int sysctl_hung_task_check_count;
extern unsigned int sysctl_hung_task_panic;
extern unsigned long sysctl_hung_task_timeout_secs;
+extern unsigned long sysctl_hung_task_check_interval_secs;
extern int sysctl_hung_task_warnings;
extern int proc_dohung_task_timeout_secs(struct ctl_table *table, int write,
void __user *buffer,
diff --git a/kernel/fork.c b/kernel/fork.c
index 8c760effa42e..8bcef2413f1b 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1302,6 +1302,7 @@ static int copy_mm(unsigned long clone_flags, struct task_struct *tsk)
tsk->nvcsw = tsk->nivcsw = 0;
#ifdef CONFIG_DETECT_HUNG_TASK
tsk->last_switch_count = tsk->nvcsw + tsk->nivcsw;
+ tsk->last_switch_time = 0;
#endif
tsk->mm = NULL;
diff --git a/kernel/hung_task.c b/kernel/hung_task.c
index 32b479468e4d..b9132d1269ef 100644
--- a/kernel/hung_task.c
+++ b/kernel/hung_task.c
@@ -40,6 +40,11 @@ int __read_mostly sysctl_hung_task_check_count = PID_MAX_LIMIT;
*/
unsigned long __read_mostly sysctl_hung_task_timeout_secs = CONFIG_DEFAULT_HUNG_TASK_TIMEOUT;
+/*
+ * Zero (default value) means use sysctl_hung_task_timeout_secs:
+ */
+unsigned long __read_mostly sysctl_hung_task_check_interval_secs;
+
int __read_mostly sysctl_hung_task_warnings = 10;
static int __read_mostly did_panic;
@@ -98,8 +103,11 @@ static void check_hung_task(struct task_struct *t, unsigned long timeout)
if (switch_count != t->last_switch_count) {
t->last_switch_count = switch_count;
+ t->last_switch_time = jiffies;
return;
}
+ if (time_is_after_jiffies(t->last_switch_time + timeout * HZ))
+ return;
trace_sched_process_hang(t);
@@ -245,8 +253,13 @@ static int watchdog(void *dummy)
for ( ; ; ) {
unsigned long timeout = sysctl_hung_task_timeout_secs;
- long t = hung_timeout_jiffies(hung_last_checked, timeout);
+ unsigned long interval = sysctl_hung_task_check_interval_secs;
+ long t;
+ if (interval == 0)
+ interval = timeout;
+ interval = min_t(unsigned long, interval, timeout);
+ t = hung_timeout_jiffies(hung_last_checked, interval);
if (t <= 0) {
if (!atomic_xchg(&reset_hung_task, 0))
check_hung_uninterruptible_tasks(timeout);
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index f22f76b7a138..dbdcb6673b27 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -145,7 +145,10 @@ static int minolduid;
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 */
+/*
+ * This is needed for proc_doulongvec_minmax of sysctl_hung_task_timeout_secs
+ * and hung_task_check_interval_secs
+ */
#ifdef CONFIG_DETECT_HUNG_TASK
static unsigned long hung_task_timeout_max = (LONG_MAX/HZ);
#endif
@@ -1091,6 +1094,14 @@ static struct ctl_table kern_table[] = {
.extra2 = &hung_task_timeout_max,
},
{
+ .procname = "hung_task_check_interval_secs",
+ .data = &sysctl_hung_task_check_interval_secs,
+ .maxlen = sizeof(unsigned long),
+ .mode = 0644,
+ .proc_handler = proc_dohung_task_timeout_secs,
+ .extra2 = &hung_task_timeout_max,
+ },
+ {
.procname = "hung_task_warnings",
.data = &sysctl_hung_task_warnings,
.maxlen = sizeof(int),