Merge branch 'core/softlockup' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip (1551260d) · Commits · e / devices / android_kernel_teracube_emerald

include/linux/sched.h

+10 −8

Original line number	Original line	Diff line number	Diff line
	@@ -300,17 +300,11 @@ extern int proc_dosoftlockup_thresh(struct ctl_table *table, int write,
	struct file filp, void __user buffer,		struct file filp, void __user buffer,
	size_t lenp, loff_t ppos);		size_t lenp, loff_t ppos);
	extern unsigned int softlockup_panic;		extern unsigned int softlockup_panic;
	extern unsigned long sysctl_hung_task_check_count;
	extern unsigned long sysctl_hung_task_timeout_secs;
	extern unsigned long sysctl_hung_task_warnings;
	extern int softlockup_thresh;		extern int softlockup_thresh;
	#else		#else
	static inline void softlockup_tick(void)		static inline void softlockup_tick(void)
	{		{
	}		}
	static inline void spawn_softlockup_task(void)
	{
	}
	static inline void touch_softlockup_watchdog(void)		static inline void touch_softlockup_watchdog(void)
	{		{
	}		}
	@@ -319,6 +313,15 @@ static inline void touch_all_softlockup_watchdogs(void)
	}		}
	#endif		#endif

			#ifdef CONFIG_DETECT_HUNG_TASK
			extern unsigned int sysctl_hung_task_panic;
			extern unsigned long sysctl_hung_task_check_count;
			extern unsigned long sysctl_hung_task_timeout_secs;
			extern unsigned long sysctl_hung_task_warnings;
			extern int proc_dohung_task_timeout_secs(struct ctl_table *table, int write,
			struct file filp, void __user buffer,
			size_t lenp, loff_t ppos);
			#endif

	/* Attach to any functions which should be ignored in wchan output. */		/* Attach to any functions which should be ignored in wchan output. */
	#define __sched __attribute__((__section__(".sched.text")))		#define __sched __attribute__((__section__(".sched.text")))
	@@ -1255,9 +1258,8 @@ struct task_struct {
	/* ipc stuff */		/* ipc stuff */
	struct sysv_sem sysvsem;		struct sysv_sem sysvsem;
	#endif		#endif
	#ifdef CONFIG_DETECT_SOFTLOCKUP		#ifdef CONFIG_DETECT_HUNG_TASK
	/* hung task detection */		/* hung task detection */
	unsigned long last_switch_timestamp;
	unsigned long last_switch_count;		unsigned long last_switch_count;
	#endif		#endif
	/* CPU-specific state of this task */		/* CPU-specific state of this task */

kernel/Makefile

+1 −0

Original line number	Original line	Diff line number	Diff line
	@@ -74,6 +74,7 @@ obj-$(CONFIG_AUDIT_TREE) += audit_tree.o
	obj-$(CONFIG_KPROBES) += kprobes.o		obj-$(CONFIG_KPROBES) += kprobes.o
	obj-$(CONFIG_KGDB) += kgdb.o		obj-$(CONFIG_KGDB) += kgdb.o
	obj-$(CONFIG_DETECT_SOFTLOCKUP) += softlockup.o		obj-$(CONFIG_DETECT_SOFTLOCKUP) += softlockup.o
			obj-$(CONFIG_DETECT_HUNG_TASK) += hung_task.o
	obj-$(CONFIG_GENERIC_HARDIRQS) += irq/		obj-$(CONFIG_GENERIC_HARDIRQS) += irq/
	obj-$(CONFIG_SECCOMP) += seccomp.o		obj-$(CONFIG_SECCOMP) += seccomp.o
	obj-$(CONFIG_RCU_TORTURE_TEST) += rcutorture.o		obj-$(CONFIG_RCU_TORTURE_TEST) += rcutorture.o

kernel/fork.c

+3 −5

Original line number	Original line	Diff line number	Diff line
	@@ -645,6 +645,9 @@ static int copy_mm(unsigned long clone_flags, struct task_struct * tsk)

	tsk->min_flt = tsk->maj_flt = 0;		tsk->min_flt = tsk->maj_flt = 0;
	tsk->nvcsw = tsk->nivcsw = 0;		tsk->nvcsw = tsk->nivcsw = 0;
			#ifdef CONFIG_DETECT_HUNG_TASK
			tsk->last_switch_count = tsk->nvcsw + tsk->nivcsw;
			#endif

	tsk->mm = NULL;		tsk->mm = NULL;
	tsk->active_mm = NULL;		tsk->active_mm = NULL;
	@@ -1032,11 +1035,6 @@ static struct task_struct *copy_process(unsigned long clone_flags,

	p->default_timer_slack_ns = current->timer_slack_ns;		p->default_timer_slack_ns = current->timer_slack_ns;

	#ifdef CONFIG_DETECT_SOFTLOCKUP
	p->last_switch_count = 0;
	p->last_switch_timestamp = 0;
	#endif

	task_io_accounting_init(&p->ioac);		task_io_accounting_init(&p->ioac);
	acct_clear_integrals(p);		acct_clear_integrals(p);

kernel/hung_task.c

0 → 100644

+217 −0

Original line number	Original line	Diff line number	Diff line
			/*
			* 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/module.h>
			#include <linux/sysctl.h>

			/*
			* The number of tasks checked:
			*/
			unsigned long __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_BATCHING 1024

			/*
			* Zero means infinite timeout - no checking done:
			*/
			unsigned long __read_mostly sysctl_hung_task_timeout_secs = 120;

			unsigned long __read_mostly sysctl_hung_task_warnings = 10;

			static int __read_mostly did_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 =
			CONFIG_BOOTPARAM_HUNG_TASK_PANIC_VALUE;

			static int __init hung_task_panic_setup(char *str)
			{
			sysctl_hung_task_panic = simple_strtoul(str, NULL, 0);

			return 1;
			}
			__setup("hung_task_panic=", hung_task_panic_setup);

			static int
			hung_task_panic(struct notifier_block this, unsigned long event, void ptr)
			{
			did_panic = 1;

			return NOTIFY_DONE;
			}

			static struct notifier_block panic_block = {
			.notifier_call = hung_task_panic,
			};

			static void check_hung_task(struct task_struct *t, unsigned long timeout)
			{
			unsigned long switch_count = t->nvcsw + t->nivcsw;

			/*
			* Ensure the task is not frozen.
			* Also, when a freshly created task is scheduled once, changes
			* its state to TASK_UNINTERRUPTIBLE without having ever been
			* switched out once, it musn't be checked.
			*/
			if (unlikely(t->flags & PF_FROZEN \|\| !switch_count))
			return;

			if (switch_count != t->last_switch_count) {
			t->last_switch_count = switch_count;
			return;
			}
			if (!sysctl_hung_task_warnings)
			return;
			sysctl_hung_task_warnings--;

			/*
			* Ok, the task did not get scheduled for more than 2 minutes,
			* complain:
			*/
			printk(KERN_ERR "INFO: task %s:%d blocked for more than "
			"%ld seconds.\n", t->comm, t->pid, timeout);
			printk(KERN_ERR "\"echo 0 > /proc/sys/kernel/hung_task_timeout_secs\""
			" disables this message.\n");
			sched_show_task(t);
			__debug_show_held_locks(t);

			touch_nmi_watchdog();

			if (sysctl_hung_task_panic)
			panic("hung_task: blocked tasks");
			}

			/*
			* To avoid extending the RCU grace period for an unbounded amount of time,
			* periodically exit the critical section and enter a new one.
			*
			* For preemptible RCU it is sufficient to call rcu_read_unlock in order
			* exit the grace period. For classic RCU, a reschedule is required.
			*/
			static void rcu_lock_break(struct task_struct g, struct task_struct t)
			{
			get_task_struct(g);
			get_task_struct(t);
			rcu_read_unlock();
			cond_resched();
			rcu_read_lock();
			put_task_struct(t);
			put_task_struct(g);
			}

			/*
			* Check whether a TASK_UNINTERRUPTIBLE does not get woken up for
			* a really long time (120 seconds). If that happens, print out
			* a warning.
			*/
			static void check_hung_uninterruptible_tasks(unsigned long timeout)
			{
			int max_count = sysctl_hung_task_check_count;
			int batch_count = HUNG_TASK_BATCHING;
			struct task_struct g, t;

			/*
			* If the system crashed already then all bets are off,
			* do not report extra hung tasks:
			*/
			if (test_taint(TAINT_DIE) \|\| did_panic)
			return;

			rcu_read_lock();
			do_each_thread(g, t) {
			if (!--max_count)
			goto unlock;
			if (!--batch_count) {
			batch_count = HUNG_TASK_BATCHING;
			rcu_lock_break(g, t);
			/* Exit if t or g was unhashed during refresh. */
			if (t->state == TASK_DEAD \|\| g->state == TASK_DEAD)
			goto unlock;
			}
			/* use "==" to skip the TASK_KILLABLE tasks waiting on NFS */
			if (t->state == TASK_UNINTERRUPTIBLE)
			check_hung_task(t, timeout);
			} while_each_thread(g, t);
			unlock:
			rcu_read_unlock();
			}

			static unsigned long timeout_jiffies(unsigned long timeout)
			{
			/* timeout of 0 will disable the watchdog */
			return timeout ? timeout * HZ : MAX_SCHEDULE_TIMEOUT;
			}

			/*
			* Process updating of timeout sysctl
			*/
			int proc_dohung_task_timeout_secs(struct ctl_table *table, int write,
			struct file filp, void __user buffer,
			size_t lenp, loff_t ppos)
			{
			int ret;

			ret = proc_doulongvec_minmax(table, write, filp, buffer, lenp, ppos);

			if (ret \|\| !write)
			goto out;

			wake_up_process(watchdog_task);

			out:
			return ret;
			}

			/*
			* kthread which checks for tasks stuck in D state
			*/
			static int watchdog(void *dummy)
			{
			set_user_nice(current, 0);

			for ( ; ; ) {
			unsigned long timeout = sysctl_hung_task_timeout_secs;

			while (schedule_timeout_interruptible(timeout_jiffies(timeout)))
			timeout = sysctl_hung_task_timeout_secs;

			check_hung_uninterruptible_tasks(timeout);
			}

			return 0;
			}

			static int __init hung_task_init(void)
			{
			atomic_notifier_chain_register(&panic_notifier_list, &panic_block);
			watchdog_task = kthread_run(watchdog, NULL, "khungtaskd");

			return 0;
			}

			module_init(hung_task_init);

kernel/softlockup.c

+0 −100

Original line number	Original line	Diff line number	Diff line
	@@ -165,98 +165,12 @@ void softlockup_tick(void)
	panic("softlockup: hung tasks");		panic("softlockup: hung tasks");
	}		}

	/*
	* Have a reasonable limit on the number of tasks checked:
	*/
	unsigned long __read_mostly sysctl_hung_task_check_count = 1024;

	/*
	* Zero means infinite timeout - no checking done:
	*/
	unsigned long __read_mostly sysctl_hung_task_timeout_secs = 480;

	unsigned long __read_mostly sysctl_hung_task_warnings = 10;

	/*
	* Only do the hung-tasks check on one CPU:
	*/
	static int check_cpu __read_mostly = -1;

	static void check_hung_task(struct task_struct *t, unsigned long now)
	{
	unsigned long switch_count = t->nvcsw + t->nivcsw;

	if (t->flags & PF_FROZEN)
	return;

	if (switch_count != t->last_switch_count \|\| !t->last_switch_timestamp) {
	t->last_switch_count = switch_count;
	t->last_switch_timestamp = now;
	return;
	}
	if ((long)(now - t->last_switch_timestamp) <
	sysctl_hung_task_timeout_secs)
	return;
	if (!sysctl_hung_task_warnings)
	return;
	sysctl_hung_task_warnings--;

	/*
	* Ok, the task did not get scheduled for more than 2 minutes,
	* complain:
	*/
	printk(KERN_ERR "INFO: task %s:%d blocked for more than "
	"%ld seconds.\n", t->comm, t->pid,
	sysctl_hung_task_timeout_secs);
	printk(KERN_ERR "\"echo 0 > /proc/sys/kernel/hung_task_timeout_secs\""
	" disables this message.\n");
	sched_show_task(t);
	__debug_show_held_locks(t);

	t->last_switch_timestamp = now;
	touch_nmi_watchdog();

	if (softlockup_panic)
	panic("softlockup: blocked tasks");
	}

	/*
	* Check whether a TASK_UNINTERRUPTIBLE does not get woken up for
	* a really long time (120 seconds). If that happens, print out
	* a warning.
	*/
	static void check_hung_uninterruptible_tasks(int this_cpu)
	{
	int max_count = sysctl_hung_task_check_count;
	unsigned long now = get_timestamp(this_cpu);
	struct task_struct g, t;

	/*
	* If the system crashed already then all bets are off,
	* do not report extra hung tasks:
	*/
	if (test_taint(TAINT_DIE) \|\| did_panic)
	return;

	read_lock(&tasklist_lock);
	do_each_thread(g, t) {
	if (!--max_count)
	goto unlock;
	/* use "==" to skip the TASK_KILLABLE tasks waiting on NFS */
	if (t->state == TASK_UNINTERRUPTIBLE)
	check_hung_task(t, now);
	} while_each_thread(g, t);
	unlock:
	read_unlock(&tasklist_lock);
	}

	/*		/*
	* The watchdog thread - runs every second and touches the timestamp.		* The watchdog thread - runs every second and touches the timestamp.
	*/		*/
	static int watchdog(void *__bind_cpu)		static int watchdog(void *__bind_cpu)
	{		{
	struct sched_param param = { .sched_priority = MAX_RT_PRIO-1 };		struct sched_param param = { .sched_priority = MAX_RT_PRIO-1 };
	int this_cpu = (long)__bind_cpu;

	sched_setscheduler(current, SCHED_FIFO, &param);		sched_setscheduler(current, SCHED_FIFO, &param);

	@@ -276,11 +190,6 @@ static int watchdog(void *__bind_cpu)
	if (kthread_should_stop())		if (kthread_should_stop())
	break;		break;

	if (this_cpu == check_cpu) {
	if (sysctl_hung_task_timeout_secs)
	check_hung_uninterruptible_tasks(this_cpu);
	}

	set_current_state(TASK_INTERRUPTIBLE);		set_current_state(TASK_INTERRUPTIBLE);
	}		}
	__set_current_state(TASK_RUNNING);		__set_current_state(TASK_RUNNING);
	@@ -312,18 +221,9 @@ cpu_callback(struct notifier_block nfb, unsigned long action, void hcpu)
	break;		break;
	case CPU_ONLINE:		case CPU_ONLINE:
	case CPU_ONLINE_FROZEN:		case CPU_ONLINE_FROZEN:
	check_cpu = cpumask_any(cpu_online_mask);
	wake_up_process(per_cpu(watchdog_task, hotcpu));		wake_up_process(per_cpu(watchdog_task, hotcpu));
	break;		break;
	#ifdef CONFIG_HOTPLUG_CPU		#ifdef CONFIG_HOTPLUG_CPU
	case CPU_DOWN_PREPARE:
	case CPU_DOWN_PREPARE_FROZEN:
	if (hotcpu == check_cpu) {
	/* Pick any other online cpu. */
	check_cpu = cpumask_any_but(cpu_online_mask, hotcpu);
	}
	break;

	case CPU_UP_CANCELED:		case CPU_UP_CANCELED:
	case CPU_UP_CANCELED_FROZEN:		case CPU_UP_CANCELED_FROZEN:
	if (!per_cpu(watchdog_task, hotcpu))		if (!per_cpu(watchdog_task, hotcpu))