diff options
Diffstat (limited to 'include/linux/workqueue.h')
| -rw-r--r-- | include/linux/workqueue.h | 205 |
1 files changed, 169 insertions, 36 deletions
diff --git a/include/linux/workqueue.h b/include/linux/workqueue.h index 9466e860d8c2..0c0771f06bfa 100644 --- a/include/linux/workqueue.h +++ b/include/linux/workqueue.h @@ -9,6 +9,7 @@ #include <linux/linkage.h> #include <linux/bitops.h> #include <linux/lockdep.h> +#include <linux/threads.h> #include <asm/atomic.h> struct workqueue_struct; @@ -22,12 +23,61 @@ typedef void (*work_func_t)(struct work_struct *work); */ #define work_data_bits(work) ((unsigned long *)(&(work)->data)) +enum { + WORK_STRUCT_PENDING_BIT = 0, /* work item is pending execution */ + WORK_STRUCT_DELAYED_BIT = 1, /* work item is delayed */ + WORK_STRUCT_CWQ_BIT = 2, /* data points to cwq */ + WORK_STRUCT_LINKED_BIT = 3, /* next work is linked to this one */ +#ifdef CONFIG_DEBUG_OBJECTS_WORK + WORK_STRUCT_STATIC_BIT = 4, /* static initializer (debugobjects) */ + WORK_STRUCT_COLOR_SHIFT = 5, /* color for workqueue flushing */ +#else + WORK_STRUCT_COLOR_SHIFT = 4, /* color for workqueue flushing */ +#endif + + WORK_STRUCT_COLOR_BITS = 4, + + WORK_STRUCT_PENDING = 1 << WORK_STRUCT_PENDING_BIT, + WORK_STRUCT_DELAYED = 1 << WORK_STRUCT_DELAYED_BIT, + WORK_STRUCT_CWQ = 1 << WORK_STRUCT_CWQ_BIT, + WORK_STRUCT_LINKED = 1 << WORK_STRUCT_LINKED_BIT, +#ifdef CONFIG_DEBUG_OBJECTS_WORK + WORK_STRUCT_STATIC = 1 << WORK_STRUCT_STATIC_BIT, +#else + WORK_STRUCT_STATIC = 0, +#endif + + /* + * The last color is no color used for works which don't + * participate in workqueue flushing. + */ + WORK_NR_COLORS = (1 << WORK_STRUCT_COLOR_BITS) - 1, + WORK_NO_COLOR = WORK_NR_COLORS, + + /* special cpu IDs */ + WORK_CPU_UNBOUND = NR_CPUS, + WORK_CPU_NONE = NR_CPUS + 1, + WORK_CPU_LAST = WORK_CPU_NONE, + + /* + * Reserve 7 bits off of cwq pointer w/ debugobjects turned + * off. This makes cwqs aligned to 256 bytes and allows 15 + * workqueue flush colors. + */ + WORK_STRUCT_FLAG_BITS = WORK_STRUCT_COLOR_SHIFT + + WORK_STRUCT_COLOR_BITS, + + WORK_STRUCT_FLAG_MASK = (1UL << WORK_STRUCT_FLAG_BITS) - 1, + WORK_STRUCT_WQ_DATA_MASK = ~WORK_STRUCT_FLAG_MASK, + WORK_STRUCT_NO_CPU = WORK_CPU_NONE << WORK_STRUCT_FLAG_BITS, + + /* bit mask for work_busy() return values */ + WORK_BUSY_PENDING = 1 << 0, + WORK_BUSY_RUNNING = 1 << 1, +}; + struct work_struct { atomic_long_t data; -#define WORK_STRUCT_PENDING 0 /* T if work item pending execution */ -#define WORK_STRUCT_STATIC 1 /* static initializer (debugobjects) */ -#define WORK_STRUCT_FLAG_MASK (3UL) -#define WORK_STRUCT_WQ_DATA_MASK (~WORK_STRUCT_FLAG_MASK) struct list_head entry; work_func_t func; #ifdef CONFIG_LOCKDEP @@ -35,8 +85,9 @@ struct work_struct { #endif }; -#define WORK_DATA_INIT() ATOMIC_LONG_INIT(0) -#define WORK_DATA_STATIC_INIT() ATOMIC_LONG_INIT(2) +#define WORK_DATA_INIT() ATOMIC_LONG_INIT(WORK_STRUCT_NO_CPU) +#define WORK_DATA_STATIC_INIT() \ + ATOMIC_LONG_INIT(WORK_STRUCT_NO_CPU | WORK_STRUCT_STATIC) struct delayed_work { struct work_struct work; @@ -96,9 +147,14 @@ struct execute_work { #ifdef CONFIG_DEBUG_OBJECTS_WORK extern void __init_work(struct work_struct *work, int onstack); extern void destroy_work_on_stack(struct work_struct *work); +static inline unsigned int work_static(struct work_struct *work) +{ + return *work_data_bits(work) & WORK_STRUCT_STATIC; +} #else static inline void __init_work(struct work_struct *work, int onstack) { } static inline void destroy_work_on_stack(struct work_struct *work) { } +static inline unsigned int work_static(struct work_struct *work) { return 0; } #endif /* @@ -134,7 +190,7 @@ static inline void destroy_work_on_stack(struct work_struct *work) { } __INIT_WORK((_work), (_func), 0); \ } while (0) -#define INIT_WORK_ON_STACK(_work, _func) \ +#define INIT_WORK_ONSTACK(_work, _func) \ do { \ __INIT_WORK((_work), (_func), 1); \ } while (0) @@ -145,9 +201,9 @@ static inline void destroy_work_on_stack(struct work_struct *work) { } init_timer(&(_work)->timer); \ } while (0) -#define INIT_DELAYED_WORK_ON_STACK(_work, _func) \ +#define INIT_DELAYED_WORK_ONSTACK(_work, _func) \ do { \ - INIT_WORK_ON_STACK(&(_work)->work, (_func)); \ + INIT_WORK_ONSTACK(&(_work)->work, (_func)); \ init_timer_on_stack(&(_work)->timer); \ } while (0) @@ -162,7 +218,7 @@ static inline void destroy_work_on_stack(struct work_struct *work) { } * @work: The work item in question */ #define work_pending(work) \ - test_bit(WORK_STRUCT_PENDING, work_data_bits(work)) + test_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(work)) /** * delayed_work_pending - Find out whether a delayable work item is currently @@ -177,16 +233,63 @@ static inline void destroy_work_on_stack(struct work_struct *work) { } * @work: The work item in question */ #define work_clear_pending(work) \ - clear_bit(WORK_STRUCT_PENDING, work_data_bits(work)) + clear_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(work)) +/* + * Workqueue flags and constants. For details, please refer to + * Documentation/workqueue.txt. + */ +enum { + WQ_NON_REENTRANT = 1 << 0, /* guarantee non-reentrance */ + WQ_UNBOUND = 1 << 1, /* not bound to any cpu */ + WQ_FREEZEABLE = 1 << 2, /* freeze during suspend */ + WQ_MEM_RECLAIM = 1 << 3, /* may be used for memory reclaim */ + WQ_HIGHPRI = 1 << 4, /* high priority */ + WQ_CPU_INTENSIVE = 1 << 5, /* cpu instensive workqueue */ + + WQ_DYING = 1 << 6, /* internal: workqueue is dying */ + WQ_RESCUER = 1 << 7, /* internal: workqueue has rescuer */ + + WQ_MAX_ACTIVE = 512, /* I like 512, better ideas? */ + WQ_MAX_UNBOUND_PER_CPU = 4, /* 4 * #cpus for unbound wq */ + WQ_DFL_ACTIVE = WQ_MAX_ACTIVE / 2, +}; + +/* unbound wq's aren't per-cpu, scale max_active according to #cpus */ +#define WQ_UNBOUND_MAX_ACTIVE \ + max_t(int, WQ_MAX_ACTIVE, num_possible_cpus() * WQ_MAX_UNBOUND_PER_CPU) + +/* + * System-wide workqueues which are always present. + * + * system_wq is the one used by schedule[_delayed]_work[_on](). + * Multi-CPU multi-threaded. There are users which expect relatively + * short queue flush time. Don't queue works which can run for too + * long. + * + * system_long_wq is similar to system_wq but may host long running + * works. Queue flushing might take relatively long. + * + * system_nrt_wq is non-reentrant and guarantees that any given work + * item is never executed in parallel by multiple CPUs. Queue + * flushing might take relatively long. + * + * system_unbound_wq is unbound workqueue. Workers are not bound to + * any specific CPU, not concurrency managed, and all queued works are + * executed immediately as long as max_active limit is not reached and + * resources are available. + */ +extern struct workqueue_struct *system_wq; +extern struct workqueue_struct *system_long_wq; +extern struct workqueue_struct *system_nrt_wq; +extern struct workqueue_struct *system_unbound_wq; extern struct workqueue_struct * -__create_workqueue_key(const char *name, int singlethread, - int freezeable, int rt, struct lock_class_key *key, - const char *lock_name); +__alloc_workqueue_key(const char *name, unsigned int flags, int max_active, + struct lock_class_key *key, const char *lock_name); #ifdef CONFIG_LOCKDEP -#define __create_workqueue(name, singlethread, freezeable, rt) \ +#define alloc_workqueue(name, flags, max_active) \ ({ \ static struct lock_class_key __key; \ const char *__lock_name; \ @@ -196,20 +299,38 @@ __create_workqueue_key(const char *name, int singlethread, else \ __lock_name = #name; \ \ - __create_workqueue_key((name), (singlethread), \ - (freezeable), (rt), &__key, \ - __lock_name); \ + __alloc_workqueue_key((name), (flags), (max_active), \ + &__key, __lock_name); \ }) #else -#define __create_workqueue(name, singlethread, freezeable, rt) \ - __create_workqueue_key((name), (singlethread), (freezeable), (rt), \ - NULL, NULL) +#define alloc_workqueue(name, flags, max_active) \ + __alloc_workqueue_key((name), (flags), (max_active), NULL, NULL) #endif -#define create_workqueue(name) __create_workqueue((name), 0, 0, 0) -#define create_rt_workqueue(name) __create_workqueue((name), 0, 0, 1) -#define create_freezeable_workqueue(name) __create_workqueue((name), 1, 1, 0) -#define create_singlethread_workqueue(name) __create_workqueue((name), 1, 0, 0) +/** + * alloc_ordered_workqueue - allocate an ordered workqueue + * @name: name of the workqueue + * @flags: WQ_* flags (only WQ_FREEZEABLE and WQ_MEM_RECLAIM are meaningful) + * + * Allocate an ordered workqueue. An ordered workqueue executes at + * most one work item at any given time in the queued order. They are + * implemented as unbound workqueues with @max_active of one. + * + * RETURNS: + * Pointer to the allocated workqueue on success, %NULL on failure. + */ +static inline struct workqueue_struct * +alloc_ordered_workqueue(const char *name, unsigned int flags) +{ + return alloc_workqueue(name, WQ_UNBOUND | flags, 1); +} + +#define create_workqueue(name) \ + alloc_workqueue((name), WQ_MEM_RECLAIM, 1) +#define create_freezeable_workqueue(name) \ + alloc_workqueue((name), WQ_FREEZEABLE | WQ_UNBOUND | WQ_MEM_RECLAIM, 1) +#define create_singlethread_workqueue(name) \ + alloc_workqueue((name), WQ_UNBOUND | WQ_MEM_RECLAIM, 1) extern void destroy_workqueue(struct workqueue_struct *wq); @@ -223,7 +344,6 @@ extern int queue_delayed_work_on(int cpu, struct workqueue_struct *wq, extern void flush_workqueue(struct workqueue_struct *wq); extern void flush_scheduled_work(void); -extern void flush_delayed_work(struct delayed_work *work); extern int schedule_work(struct work_struct *work); extern int schedule_work_on(int cpu, struct work_struct *work); @@ -231,15 +351,23 @@ extern int schedule_delayed_work(struct delayed_work *work, unsigned long delay) extern int schedule_delayed_work_on(int cpu, struct delayed_work *work, unsigned long delay); extern int schedule_on_each_cpu(work_func_t func); -extern int current_is_keventd(void); extern int keventd_up(void); -extern void init_workqueues(void); int execute_in_process_context(work_func_t fn, struct execute_work *); -extern int flush_work(struct work_struct *work); +extern bool flush_work(struct work_struct *work); +extern bool flush_work_sync(struct work_struct *work); +extern bool cancel_work_sync(struct work_struct *work); -extern int cancel_work_sync(struct work_struct *work); +extern bool flush_delayed_work(struct delayed_work *dwork); +extern bool flush_delayed_work_sync(struct delayed_work *work); +extern bool cancel_delayed_work_sync(struct delayed_work *dwork); + +extern void workqueue_set_max_active(struct workqueue_struct *wq, + int max_active); +extern bool workqueue_congested(unsigned int cpu, struct workqueue_struct *wq); +extern unsigned int work_cpu(struct work_struct *work); +extern unsigned int work_busy(struct work_struct *work); /* * Kill off a pending schedule_delayed_work(). Note that the work callback @@ -247,9 +375,9 @@ extern int cancel_work_sync(struct work_struct *work); * it returns 1 and the work doesn't re-arm itself. Run flush_workqueue() or * cancel_work_sync() to wait on it. */ -static inline int cancel_delayed_work(struct delayed_work *work) +static inline bool cancel_delayed_work(struct delayed_work *work) { - int ret; + bool ret; ret = del_timer_sync(&work->timer); if (ret) @@ -262,9 +390,9 @@ static inline int cancel_delayed_work(struct delayed_work *work) * if it returns 0 the timer function may be running and the queueing is in * progress. */ -static inline int __cancel_delayed_work(struct delayed_work *work) +static inline bool __cancel_delayed_work(struct delayed_work *work) { - int ret; + bool ret; ret = del_timer(&work->timer); if (ret) @@ -272,8 +400,6 @@ static inline int __cancel_delayed_work(struct delayed_work *work) return ret; } -extern int cancel_delayed_work_sync(struct delayed_work *work); - /* Obsolete. use cancel_delayed_work_sync() */ static inline void cancel_rearming_delayed_workqueue(struct workqueue_struct *wq, @@ -297,4 +423,11 @@ static inline long work_on_cpu(unsigned int cpu, long (*fn)(void *), void *arg) #else long work_on_cpu(unsigned int cpu, long (*fn)(void *), void *arg); #endif /* CONFIG_SMP */ + +#ifdef CONFIG_FREEZER +extern void freeze_workqueues_begin(void); +extern bool freeze_workqueues_busy(void); +extern void thaw_workqueues(void); +#endif /* CONFIG_FREEZER */ + #endif |