linux-imx

// SPDX-License-Identifier: GPL-2.0-only

/*

 * Detect Hung Task

 *

 * kernel/hung_task.c - kernel thread for detecting tasks stuck in D state

 *

 */

​

#include <linux/mm.h>

#include <linux/cpu.h>

#include <linux/nmi.h>

#include <linux/init.h>

#include <linux/delay.h>

#include <linux/freezer.h>

#include <linux/kthread.h>

#include <linux/lockdep.h>

#include <linux/export.h>

#include <linux/sysctl.h>

#include <linux/suspend.h>

#include <linux/utsname.h>

#include <linux/sched/signal.h>

#include <linux/sched/debug.h>

#include <linux/sched/sysctl.h>

​

#include <trace/events/sched.h>

​

/*

 * The number of tasks checked:

 */

int __read_mostly sysctl_hung_task_check_count = PID_MAX_LIMIT;

​

/*

 * Limit number of tasks checked in a batch.

 *

 * This value controls the preemptibility of khungtaskd since preemption

 * is disabled during the critical section. It also controls the size of

 * the RCU grace period. So it needs to be upper-bound.

 */

#define HUNG_TASK_LOCK_BREAK (HZ / 10)

​

/*

 * Zero means infinite timeout - no checking done:

 */

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;

static bool hung_task_show_lock;

static bool hung_task_call_panic;

​

static struct task_struct *watchdog_task;

​

/*

 * Should we panic (and reboot, if panic_timeout= is set) when a

 * hung task is detected:

 */

unsigned int __read_mostly sysctl_hung_task_panic =