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		6f2b9b9a9d
		
	
	
	
	
		
			
			This modifies the timer code in a way to allow lockdep to detect deadlocks resulting from a lock being taken in the timer function as well as around the del_timer_sync() call. Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
		
			
				
	
	
		
			270 lines
		
	
	
		
			7.5 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			270 lines
		
	
	
		
			7.5 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| #ifndef _LINUX_TIMER_H
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| #define _LINUX_TIMER_H
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| 
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| #include <linux/list.h>
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| #include <linux/ktime.h>
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| #include <linux/stddef.h>
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| #include <linux/debugobjects.h>
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| #include <linux/stringify.h>
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| 
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| struct tvec_base;
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| 
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| struct timer_list {
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| 	struct list_head entry;
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| 	unsigned long expires;
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| 
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| 	void (*function)(unsigned long);
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| 	unsigned long data;
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| 
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| 	struct tvec_base *base;
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| #ifdef CONFIG_TIMER_STATS
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| 	void *start_site;
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| 	char start_comm[16];
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| 	int start_pid;
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| #endif
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| #ifdef CONFIG_LOCKDEP
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| 	struct lockdep_map lockdep_map;
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| #endif
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| };
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| 
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| extern struct tvec_base boot_tvec_bases;
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| 
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| #ifdef CONFIG_LOCKDEP
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| /*
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|  * NB: because we have to copy the lockdep_map, setting the lockdep_map key
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|  * (second argument) here is required, otherwise it could be initialised to
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|  * the copy of the lockdep_map later! We use the pointer to and the string
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|  * "<file>:<line>" as the key resp. the name of the lockdep_map.
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|  */
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| #define __TIMER_LOCKDEP_MAP_INITIALIZER(_kn)				\
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| 	.lockdep_map = STATIC_LOCKDEP_MAP_INIT(_kn, &_kn),
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| #else
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| #define __TIMER_LOCKDEP_MAP_INITIALIZER(_kn)
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| #endif
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| 
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| #define TIMER_INITIALIZER(_function, _expires, _data) {		\
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| 		.entry = { .prev = TIMER_ENTRY_STATIC },	\
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| 		.function = (_function),			\
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| 		.expires = (_expires),				\
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| 		.data = (_data),				\
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| 		.base = &boot_tvec_bases,			\
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| 		__TIMER_LOCKDEP_MAP_INITIALIZER(		\
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| 			__FILE__ ":" __stringify(__LINE__))	\
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| 	}
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| 
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| #define DEFINE_TIMER(_name, _function, _expires, _data)		\
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| 	struct timer_list _name =				\
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| 		TIMER_INITIALIZER(_function, _expires, _data)
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| 
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| void init_timer_key(struct timer_list *timer,
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| 		    const char *name,
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| 		    struct lock_class_key *key);
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| void init_timer_deferrable_key(struct timer_list *timer,
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| 			       const char *name,
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| 			       struct lock_class_key *key);
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| 
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| #ifdef CONFIG_LOCKDEP
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| #define init_timer(timer)						\
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| 	do {								\
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| 		static struct lock_class_key __key;			\
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| 		init_timer_key((timer), #timer, &__key);		\
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| 	} while (0)
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| 
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| #define init_timer_deferrable(timer)					\
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| 	do {								\
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| 		static struct lock_class_key __key;			\
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| 		init_timer_deferrable_key((timer), #timer, &__key);	\
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| 	} while (0)
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| 
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| #define init_timer_on_stack(timer)					\
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| 	do {								\
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| 		static struct lock_class_key __key;			\
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| 		init_timer_on_stack_key((timer), #timer, &__key);	\
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| 	} while (0)
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| 
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| #define setup_timer(timer, fn, data)					\
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| 	do {								\
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| 		static struct lock_class_key __key;			\
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| 		setup_timer_key((timer), #timer, &__key, (fn), (data));\
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| 	} while (0)
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| 
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| #define setup_timer_on_stack(timer, fn, data)				\
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| 	do {								\
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| 		static struct lock_class_key __key;			\
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| 		setup_timer_on_stack_key((timer), #timer, &__key,	\
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| 					 (fn), (data));			\
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| 	} while (0)
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| #else
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| #define init_timer(timer)\
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| 	init_timer_key((timer), NULL, NULL)
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| #define init_timer_deferrable(timer)\
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| 	init_timer_deferrable_key((timer), NULL, NULL)
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| #define init_timer_on_stack(timer)\
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| 	init_timer_on_stack_key((timer), NULL, NULL)
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| #define setup_timer(timer, fn, data)\
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| 	setup_timer_key((timer), NULL, NULL, (fn), (data))
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| #define setup_timer_on_stack(timer, fn, data)\
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| 	setup_timer_on_stack_key((timer), NULL, NULL, (fn), (data))
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| #endif
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| 
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| #ifdef CONFIG_DEBUG_OBJECTS_TIMERS
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| extern void init_timer_on_stack_key(struct timer_list *timer,
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| 				    const char *name,
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| 				    struct lock_class_key *key);
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| extern void destroy_timer_on_stack(struct timer_list *timer);
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| #else
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| static inline void destroy_timer_on_stack(struct timer_list *timer) { }
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| static inline void init_timer_on_stack_key(struct timer_list *timer,
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| 					   const char *name,
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| 					   struct lock_class_key *key)
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| {
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| 	init_timer_key(timer, name, key);
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| }
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| #endif
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| 
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| static inline void setup_timer_key(struct timer_list * timer,
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| 				const char *name,
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| 				struct lock_class_key *key,
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| 				void (*function)(unsigned long),
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| 				unsigned long data)
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| {
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| 	timer->function = function;
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| 	timer->data = data;
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| 	init_timer_key(timer, name, key);
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| }
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| 
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| static inline void setup_timer_on_stack_key(struct timer_list *timer,
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| 					const char *name,
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| 					struct lock_class_key *key,
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| 					void (*function)(unsigned long),
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| 					unsigned long data)
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| {
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| 	timer->function = function;
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| 	timer->data = data;
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| 	init_timer_on_stack_key(timer, name, key);
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| }
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| 
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| /**
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|  * timer_pending - is a timer pending?
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|  * @timer: the timer in question
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|  *
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|  * timer_pending will tell whether a given timer is currently pending,
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|  * or not. Callers must ensure serialization wrt. other operations done
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|  * to this timer, eg. interrupt contexts, or other CPUs on SMP.
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|  *
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|  * return value: 1 if the timer is pending, 0 if not.
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|  */
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| static inline int timer_pending(const struct timer_list * timer)
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| {
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| 	return timer->entry.next != NULL;
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| }
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| 
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| extern void add_timer_on(struct timer_list *timer, int cpu);
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| extern int del_timer(struct timer_list * timer);
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| extern int __mod_timer(struct timer_list *timer, unsigned long expires);
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| extern int mod_timer(struct timer_list *timer, unsigned long expires);
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| 
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| /*
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|  * The jiffies value which is added to now, when there is no timer
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|  * in the timer wheel:
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|  */
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| #define NEXT_TIMER_MAX_DELTA	((1UL << 30) - 1)
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| 
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| /*
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|  * Return when the next timer-wheel timeout occurs (in absolute jiffies),
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|  * locks the timer base:
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|  */
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| extern unsigned long next_timer_interrupt(void);
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| /*
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|  * Return when the next timer-wheel timeout occurs (in absolute jiffies),
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|  * locks the timer base and does the comparison against the given
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|  * jiffie.
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|  */
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| extern unsigned long get_next_timer_interrupt(unsigned long now);
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| 
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| /*
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|  * Timer-statistics info:
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|  */
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| #ifdef CONFIG_TIMER_STATS
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| 
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| #define TIMER_STATS_FLAG_DEFERRABLE	0x1
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| 
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| extern void init_timer_stats(void);
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| 
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| extern void timer_stats_update_stats(void *timer, pid_t pid, void *startf,
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| 				     void *timerf, char *comm,
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| 				     unsigned int timer_flag);
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| 
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| extern void __timer_stats_timer_set_start_info(struct timer_list *timer,
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| 					       void *addr);
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| 
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| static inline void timer_stats_timer_set_start_info(struct timer_list *timer)
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| {
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| 	__timer_stats_timer_set_start_info(timer, __builtin_return_address(0));
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| }
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| 
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| static inline void timer_stats_timer_clear_start_info(struct timer_list *timer)
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| {
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| 	timer->start_site = NULL;
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| }
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| #else
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| static inline void init_timer_stats(void)
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| {
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| }
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| 
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| static inline void timer_stats_timer_set_start_info(struct timer_list *timer)
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| {
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| }
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| 
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| static inline void timer_stats_timer_clear_start_info(struct timer_list *timer)
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| {
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| }
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| #endif
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| 
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| /**
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|  * add_timer - start a timer
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|  * @timer: the timer to be added
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|  *
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|  * The kernel will do a ->function(->data) callback from the
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|  * timer interrupt at the ->expires point in the future. The
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|  * current time is 'jiffies'.
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|  *
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|  * The timer's ->expires, ->function (and if the handler uses it, ->data)
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|  * fields must be set prior calling this function.
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|  *
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|  * Timers with an ->expires field in the past will be executed in the next
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|  * timer tick.
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|  */
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| static inline void add_timer(struct timer_list *timer)
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| {
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| 	BUG_ON(timer_pending(timer));
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| 	__mod_timer(timer, timer->expires);
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| }
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| 
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| #ifdef CONFIG_SMP
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|   extern int try_to_del_timer_sync(struct timer_list *timer);
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|   extern int del_timer_sync(struct timer_list *timer);
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| #else
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| # define try_to_del_timer_sync(t)	del_timer(t)
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| # define del_timer_sync(t)		del_timer(t)
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| #endif
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| 
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| #define del_singleshot_timer_sync(t) del_timer_sync(t)
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| 
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| extern void init_timers(void);
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| extern void run_local_timers(void);
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| struct hrtimer;
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| extern enum hrtimer_restart it_real_fn(struct hrtimer *);
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| 
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| unsigned long __round_jiffies(unsigned long j, int cpu);
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| unsigned long __round_jiffies_relative(unsigned long j, int cpu);
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| unsigned long round_jiffies(unsigned long j);
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| unsigned long round_jiffies_relative(unsigned long j);
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| 
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| unsigned long __round_jiffies_up(unsigned long j, int cpu);
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| unsigned long __round_jiffies_up_relative(unsigned long j, int cpu);
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| unsigned long round_jiffies_up(unsigned long j);
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| unsigned long round_jiffies_up_relative(unsigned long j);
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| 
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| #endif
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