diff options
Diffstat (limited to 'include/linux/workqueue.h')
| -rw-r--r-- | include/linux/workqueue.h | 122 |
1 files changed, 98 insertions, 24 deletions
diff --git a/include/linux/workqueue.h b/include/linux/workqueue.h index af155450cab..c2bc735da74 100644 --- a/include/linux/workqueue.h +++ b/include/linux/workqueue.h @@ -16,6 +16,7 @@ struct workqueue_struct; struct work_struct; typedef void (*work_func_t)(struct work_struct *work); +void delayed_work_timer_fn(unsigned long __data); /* * The first word is the work queue pointer and the flags rolled into @@ -67,9 +68,18 @@ enum { WORK_STRUCT_FLAG_BITS = WORK_STRUCT_COLOR_SHIFT + WORK_STRUCT_COLOR_BITS, + /* data contains off-queue information when !WORK_STRUCT_CWQ */ + WORK_OFFQ_FLAG_BASE = WORK_STRUCT_FLAG_BITS, + + WORK_OFFQ_CANCELING = (1 << WORK_OFFQ_FLAG_BASE), + + WORK_OFFQ_FLAG_BITS = 1, + WORK_OFFQ_CPU_SHIFT = WORK_OFFQ_FLAG_BASE + WORK_OFFQ_FLAG_BITS, + + /* convenience constants */ 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, + WORK_STRUCT_NO_CPU = (unsigned long)WORK_CPU_NONE << WORK_OFFQ_CPU_SHIFT, /* bit mask for work_busy() return values */ WORK_BUSY_PENDING = 1 << 0, @@ -92,6 +102,7 @@ struct work_struct { struct delayed_work { struct work_struct work; struct timer_list timer; + int cpu; }; static inline struct delayed_work *to_delayed_work(struct work_struct *work) @@ -124,12 +135,14 @@ struct execute_work { #define __DELAYED_WORK_INITIALIZER(n, f) { \ .work = __WORK_INITIALIZER((n).work, (f)), \ - .timer = TIMER_INITIALIZER(NULL, 0, 0), \ + .timer = TIMER_INITIALIZER(delayed_work_timer_fn, \ + 0, (unsigned long)&(n)), \ } #define __DEFERRED_WORK_INITIALIZER(n, f) { \ .work = __WORK_INITIALIZER((n).work, (f)), \ - .timer = TIMER_DEFERRED_INITIALIZER(NULL, 0, 0), \ + .timer = TIMER_DEFERRED_INITIALIZER(delayed_work_timer_fn, \ + 0, (unsigned long)&(n)), \ } #define DECLARE_WORK(n, f) \ @@ -207,18 +220,24 @@ static inline unsigned int work_static(struct work_struct *work) { return 0; } do { \ INIT_WORK(&(_work)->work, (_func)); \ init_timer(&(_work)->timer); \ + (_work)->timer.function = delayed_work_timer_fn;\ + (_work)->timer.data = (unsigned long)(_work); \ } while (0) #define INIT_DELAYED_WORK_ONSTACK(_work, _func) \ do { \ INIT_WORK_ONSTACK(&(_work)->work, (_func)); \ init_timer_on_stack(&(_work)->timer); \ + (_work)->timer.function = delayed_work_timer_fn;\ + (_work)->timer.data = (unsigned long)(_work); \ } while (0) #define INIT_DELAYED_WORK_DEFERRABLE(_work, _func) \ do { \ INIT_WORK(&(_work)->work, (_func)); \ init_timer_deferrable(&(_work)->timer); \ + (_work)->timer.function = delayed_work_timer_fn;\ + (_work)->timer.data = (unsigned long)(_work); \ } while (0) /** @@ -255,8 +274,35 @@ enum { WQ_HIGHPRI = 1 << 4, /* high priority */ WQ_CPU_INTENSIVE = 1 << 5, /* cpu instensive workqueue */ - WQ_DRAINING = 1 << 6, /* internal: workqueue is draining */ - WQ_RESCUER = 1 << 7, /* internal: workqueue has rescuer */ + /* + * Per-cpu workqueues are generally preferred because they tend to + * show better performance thanks to cache locality. Per-cpu + * workqueues exclude the scheduler from choosing the CPU to + * execute the worker threads, which has an unfortunate side effect + * of increasing power consumption. + * + * The scheduler considers a CPU idle if it doesn't have any task + * to execute and tries to keep idle cores idle to conserve power; + * however, for example, a per-cpu work item scheduled from an + * interrupt handler on an idle CPU will force the scheduler to + * excute the work item on that CPU breaking the idleness, which in + * turn may lead to more scheduling choices which are sub-optimal + * in terms of power consumption. + * + * Workqueues marked with WQ_POWER_EFFICIENT are per-cpu by default + * but become unbound if workqueue.power_efficient kernel param is + * specified. Per-cpu workqueues which are identified to + * contribute significantly to power-consumption are identified and + * marked with this flag and enabling the power_efficient mode + * leads to noticeable power saving at the cost of small + * performance disadvantage. + * + * http://thread.gmane.org/gmane.linux.kernel/1480396 + */ + WQ_POWER_EFFICIENT = 1 << 7, + + WQ_DRAINING = 1 << 16, /* internal: workqueue is draining */ + WQ_RESCUER = 1 << 17, /* internal: workqueue has rescuer */ WQ_MAX_ACTIVE = 512, /* I like 512, better ideas? */ WQ_MAX_UNBOUND_PER_CPU = 4, /* 4 * #cpus for unbound wq */ @@ -278,10 +324,6 @@ enum { * 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 @@ -290,15 +332,32 @@ enum { * system_freezable_wq is equivalent to system_wq except that it's * freezable. * - * system_nrt_freezable_wq is equivalent to system_nrt_wq except that - * it's freezable. + * *_power_efficient_wq are inclined towards saving power and converted + * into WQ_UNBOUND variants if 'wq_power_efficient' is enabled; otherwise, + * they are same as their non-power-efficient counterparts - e.g. + * system_power_efficient_wq is identical to system_wq if + * 'wq_power_efficient' is disabled. See WQ_POWER_EFFICIENT for more info. */ 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 *system_freezable_wq; -extern struct workqueue_struct *system_nrt_freezable_wq; +extern struct workqueue_struct *system_power_efficient_wq; +extern struct workqueue_struct *system_freezable_power_efficient_wq; + +static inline struct workqueue_struct *__system_nrt_wq(void) +{ + return system_wq; +} + +static inline struct workqueue_struct *__system_nrt_freezable_wq(void) +{ + return system_freezable_wq; +} + +/* equivlalent to system_wq and system_freezable_wq, deprecated */ +#define system_nrt_wq __system_nrt_wq() +#define system_nrt_freezable_wq __system_nrt_freezable_wq() extern struct workqueue_struct * __alloc_workqueue_key(const char *fmt, unsigned int flags, int max_active, @@ -365,34 +424,37 @@ __alloc_workqueue_key(const char *fmt, unsigned int flags, int max_active, extern void destroy_workqueue(struct workqueue_struct *wq); -extern int queue_work(struct workqueue_struct *wq, struct work_struct *work); -extern int queue_work_on(int cpu, struct workqueue_struct *wq, +extern bool queue_work_on(int cpu, struct workqueue_struct *wq, struct work_struct *work); -extern int queue_delayed_work(struct workqueue_struct *wq, +extern bool queue_work(struct workqueue_struct *wq, struct work_struct *work); +extern bool queue_delayed_work_on(int cpu, struct workqueue_struct *wq, struct delayed_work *work, unsigned long delay); -extern int queue_delayed_work_on(int cpu, struct workqueue_struct *wq, +extern bool queue_delayed_work(struct workqueue_struct *wq, struct delayed_work *work, unsigned long delay); +extern bool mod_delayed_work_on(int cpu, struct workqueue_struct *wq, + struct delayed_work *dwork, unsigned long delay); +extern bool mod_delayed_work(struct workqueue_struct *wq, + struct delayed_work *dwork, unsigned long delay); extern void flush_workqueue(struct workqueue_struct *wq); extern void drain_workqueue(struct workqueue_struct *wq); extern void flush_scheduled_work(void); -extern int schedule_work(struct work_struct *work); -extern int schedule_work_on(int cpu, struct work_struct *work); -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 bool schedule_work_on(int cpu, struct work_struct *work); +extern bool schedule_work(struct work_struct *work); +extern bool schedule_delayed_work_on(int cpu, struct delayed_work *work, + unsigned long delay); +extern bool schedule_delayed_work(struct delayed_work *work, + unsigned long delay); extern int schedule_on_each_cpu(work_func_t func); extern int keventd_up(void); int execute_in_process_context(work_func_t fn, struct execute_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 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, @@ -432,6 +494,18 @@ static inline bool __cancel_delayed_work(struct delayed_work *work) return ret; } +/* used to be different but now identical to flush_work(), deprecated */ +static inline bool flush_work_sync(struct work_struct *work) +{ + return flush_work(work); +} + +/* used to be different but now identical to flush_delayed_work(), deprecated */ +static inline bool flush_delayed_work_sync(struct delayed_work *dwork) +{ + return flush_delayed_work(dwork); +} + #ifndef CONFIG_SMP static inline long work_on_cpu(unsigned int cpu, long (*fn)(void *), void *arg) { |