From 63d95a9150ee3bbd4117fcd609dee40313b454d9 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Thu, 12 Jul 2012 14:46:37 -0700 Subject: [PATCH] workqueue: use @pool instead of @gcwq or @cpu where applicable Modify all functions which deal with per-pool properties to pass around @pool instead of @gcwq or @cpu. The changes in this patch are mechanical and don't caues any functional difference. This is to prepare for multiple pools per gcwq. Signed-off-by: Tejun Heo --- kernel/workqueue.c | 218 +++++++++++++++++++++++---------------------- 1 file changed, 111 insertions(+), 107 deletions(-) diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 61f154467026..2d82f7b193a0 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -471,8 +471,10 @@ static struct global_cwq *get_gcwq(unsigned int cpu) return &unbound_global_cwq; } -static atomic_t *get_gcwq_nr_running(unsigned int cpu) +static atomic_t *get_pool_nr_running(struct worker_pool *pool) { + int cpu = pool->gcwq->cpu; + if (cpu != WORK_CPU_UNBOUND) return &per_cpu(gcwq_nr_running, cpu); else @@ -578,10 +580,10 @@ static struct global_cwq *get_work_gcwq(struct work_struct *work) * assume that they're being called with gcwq->lock held. */ -static bool __need_more_worker(struct global_cwq *gcwq) +static bool __need_more_worker(struct worker_pool *pool) { - return !atomic_read(get_gcwq_nr_running(gcwq->cpu)) || - gcwq->flags & GCWQ_HIGHPRI_PENDING; + return !atomic_read(get_pool_nr_running(pool)) || + pool->gcwq->flags & GCWQ_HIGHPRI_PENDING; } /* @@ -592,45 +594,46 @@ static bool __need_more_worker(struct global_cwq *gcwq) * function will always return %true for unbound gcwq as long as the * worklist isn't empty. */ -static bool need_more_worker(struct global_cwq *gcwq) +static bool need_more_worker(struct worker_pool *pool) { - return !list_empty(&gcwq->pool.worklist) && __need_more_worker(gcwq); + return !list_empty(&pool->worklist) && __need_more_worker(pool); } /* Can I start working? Called from busy but !running workers. */ -static bool may_start_working(struct global_cwq *gcwq) +static bool may_start_working(struct worker_pool *pool) { - return gcwq->pool.nr_idle; + return pool->nr_idle; } /* Do I need to keep working? Called from currently running workers. */ -static bool keep_working(struct global_cwq *gcwq) +static bool keep_working(struct worker_pool *pool) { - atomic_t *nr_running = get_gcwq_nr_running(gcwq->cpu); + atomic_t *nr_running = get_pool_nr_running(pool); - return !list_empty(&gcwq->pool.worklist) && + return !list_empty(&pool->worklist) && (atomic_read(nr_running) <= 1 || - gcwq->flags & GCWQ_HIGHPRI_PENDING); + pool->gcwq->flags & GCWQ_HIGHPRI_PENDING); } /* Do we need a new worker? Called from manager. */ -static bool need_to_create_worker(struct global_cwq *gcwq) +static bool need_to_create_worker(struct worker_pool *pool) { - return need_more_worker(gcwq) && !may_start_working(gcwq); + return need_more_worker(pool) && !may_start_working(pool); } /* Do I need to be the manager? */ -static bool need_to_manage_workers(struct global_cwq *gcwq) +static bool need_to_manage_workers(struct worker_pool *pool) { - return need_to_create_worker(gcwq) || gcwq->flags & GCWQ_MANAGE_WORKERS; + return need_to_create_worker(pool) || + pool->gcwq->flags & GCWQ_MANAGE_WORKERS; } /* Do we have too many workers and should some go away? */ -static bool too_many_workers(struct global_cwq *gcwq) +static bool too_many_workers(struct worker_pool *pool) { - bool managing = gcwq->flags & GCWQ_MANAGING_WORKERS; - int nr_idle = gcwq->pool.nr_idle + managing; /* manager is considered idle */ - int nr_busy = gcwq->pool.nr_workers - nr_idle; + bool managing = pool->gcwq->flags & GCWQ_MANAGING_WORKERS; + int nr_idle = pool->nr_idle + managing; /* manager is considered idle */ + int nr_busy = pool->nr_workers - nr_idle; return nr_idle > 2 && (nr_idle - 2) * MAX_IDLE_WORKERS_RATIO >= nr_busy; } @@ -640,26 +643,26 @@ static bool too_many_workers(struct global_cwq *gcwq) */ /* Return the first worker. Safe with preemption disabled */ -static struct worker *first_worker(struct global_cwq *gcwq) +static struct worker *first_worker(struct worker_pool *pool) { - if (unlikely(list_empty(&gcwq->pool.idle_list))) + if (unlikely(list_empty(&pool->idle_list))) return NULL; - return list_first_entry(&gcwq->pool.idle_list, struct worker, entry); + return list_first_entry(&pool->idle_list, struct worker, entry); } /** * wake_up_worker - wake up an idle worker - * @gcwq: gcwq to wake worker for + * @pool: worker pool to wake worker from * - * Wake up the first idle worker of @gcwq. + * Wake up the first idle worker of @pool. * * CONTEXT: * spin_lock_irq(gcwq->lock). */ -static void wake_up_worker(struct global_cwq *gcwq) +static void wake_up_worker(struct worker_pool *pool) { - struct worker *worker = first_worker(gcwq); + struct worker *worker = first_worker(pool); if (likely(worker)) wake_up_process(worker->task); @@ -681,7 +684,7 @@ void wq_worker_waking_up(struct task_struct *task, unsigned int cpu) struct worker *worker = kthread_data(task); if (!(worker->flags & WORKER_NOT_RUNNING)) - atomic_inc(get_gcwq_nr_running(cpu)); + atomic_inc(get_pool_nr_running(worker->pool)); } /** @@ -704,8 +707,7 @@ struct task_struct *wq_worker_sleeping(struct task_struct *task, { struct worker *worker = kthread_data(task), *to_wakeup = NULL; struct worker_pool *pool = worker->pool; - struct global_cwq *gcwq = pool->gcwq; - atomic_t *nr_running = get_gcwq_nr_running(cpu); + atomic_t *nr_running = get_pool_nr_running(pool); if (worker->flags & WORKER_NOT_RUNNING) return NULL; @@ -725,7 +727,7 @@ struct task_struct *wq_worker_sleeping(struct task_struct *task, * without gcwq lock is safe. */ if (atomic_dec_and_test(nr_running) && !list_empty(&pool->worklist)) - to_wakeup = first_worker(gcwq); + to_wakeup = first_worker(pool); return to_wakeup ? to_wakeup->task : NULL; } @@ -746,7 +748,6 @@ static inline void worker_set_flags(struct worker *worker, unsigned int flags, bool wakeup) { struct worker_pool *pool = worker->pool; - struct global_cwq *gcwq = pool->gcwq; WARN_ON_ONCE(worker->task != current); @@ -757,12 +758,12 @@ static inline void worker_set_flags(struct worker *worker, unsigned int flags, */ if ((flags & WORKER_NOT_RUNNING) && !(worker->flags & WORKER_NOT_RUNNING)) { - atomic_t *nr_running = get_gcwq_nr_running(gcwq->cpu); + atomic_t *nr_running = get_pool_nr_running(pool); if (wakeup) { if (atomic_dec_and_test(nr_running) && !list_empty(&pool->worklist)) - wake_up_worker(gcwq); + wake_up_worker(pool); } else atomic_dec(nr_running); } @@ -782,7 +783,7 @@ static inline void worker_set_flags(struct worker *worker, unsigned int flags, */ static inline void worker_clr_flags(struct worker *worker, unsigned int flags) { - struct global_cwq *gcwq = worker->pool->gcwq; + struct worker_pool *pool = worker->pool; unsigned int oflags = worker->flags; WARN_ON_ONCE(worker->task != current); @@ -796,7 +797,7 @@ static inline void worker_clr_flags(struct worker *worker, unsigned int flags) */ if ((flags & WORKER_NOT_RUNNING) && (oflags & WORKER_NOT_RUNNING)) if (!(worker->flags & WORKER_NOT_RUNNING)) - atomic_inc(get_gcwq_nr_running(gcwq->cpu)); + atomic_inc(get_pool_nr_running(pool)); } /** @@ -880,15 +881,15 @@ static struct worker *find_worker_executing_work(struct global_cwq *gcwq, } /** - * gcwq_determine_ins_pos - find insertion position - * @gcwq: gcwq of interest + * pool_determine_ins_pos - find insertion position + * @pool: pool of interest * @cwq: cwq a work is being queued for * - * A work for @cwq is about to be queued on @gcwq, determine insertion + * A work for @cwq is about to be queued on @pool, determine insertion * position for the work. If @cwq is for HIGHPRI wq, the work is * queued at the head of the queue but in FIFO order with respect to * other HIGHPRI works; otherwise, at the end of the queue. This - * function also sets GCWQ_HIGHPRI_PENDING flag to hint @gcwq that + * function also sets GCWQ_HIGHPRI_PENDING flag to hint @pool that * there are HIGHPRI works pending. * * CONTEXT: @@ -897,22 +898,22 @@ static struct worker *find_worker_executing_work(struct global_cwq *gcwq, * RETURNS: * Pointer to inserstion position. */ -static inline struct list_head *gcwq_determine_ins_pos(struct global_cwq *gcwq, +static inline struct list_head *pool_determine_ins_pos(struct worker_pool *pool, struct cpu_workqueue_struct *cwq) { struct work_struct *twork; if (likely(!(cwq->wq->flags & WQ_HIGHPRI))) - return &gcwq->pool.worklist; + return &pool->worklist; - list_for_each_entry(twork, &gcwq->pool.worklist, entry) { + list_for_each_entry(twork, &pool->worklist, entry) { struct cpu_workqueue_struct *tcwq = get_work_cwq(twork); if (!(tcwq->wq->flags & WQ_HIGHPRI)) break; } - gcwq->flags |= GCWQ_HIGHPRI_PENDING; + pool->gcwq->flags |= GCWQ_HIGHPRI_PENDING; return &twork->entry; } @@ -933,7 +934,7 @@ static void insert_work(struct cpu_workqueue_struct *cwq, struct work_struct *work, struct list_head *head, unsigned int extra_flags) { - struct global_cwq *gcwq = cwq->pool->gcwq; + struct worker_pool *pool = cwq->pool; /* we own @work, set data and link */ set_work_cwq(work, cwq, extra_flags); @@ -953,8 +954,8 @@ static void insert_work(struct cpu_workqueue_struct *cwq, */ smp_mb(); - if (__need_more_worker(gcwq)) - wake_up_worker(gcwq); + if (__need_more_worker(pool)) + wake_up_worker(pool); } /* @@ -1056,7 +1057,7 @@ static void __queue_work(unsigned int cpu, struct workqueue_struct *wq, if (likely(cwq->nr_active < cwq->max_active)) { trace_workqueue_activate_work(work); cwq->nr_active++; - worklist = gcwq_determine_ins_pos(gcwq, cwq); + worklist = pool_determine_ins_pos(cwq->pool, cwq); } else { work_flags |= WORK_STRUCT_DELAYED; worklist = &cwq->delayed_works; @@ -1221,7 +1222,7 @@ static void worker_enter_idle(struct worker *worker) list_add(&worker->entry, &pool->idle_list); if (likely(!(worker->flags & WORKER_ROGUE))) { - if (too_many_workers(gcwq) && !timer_pending(&pool->idle_timer)) + if (too_many_workers(pool) && !timer_pending(&pool->idle_timer)) mod_timer(&pool->idle_timer, jiffies + IDLE_WORKER_TIMEOUT); } else @@ -1234,7 +1235,7 @@ static void worker_enter_idle(struct worker *worker) */ WARN_ON_ONCE(gcwq->trustee_state == TRUSTEE_DONE && pool->nr_workers == pool->nr_idle && - atomic_read(get_gcwq_nr_running(gcwq->cpu))); + atomic_read(get_pool_nr_running(pool))); } /** @@ -1356,10 +1357,10 @@ static struct worker *alloc_worker(void) /** * create_worker - create a new workqueue worker - * @gcwq: gcwq the new worker will belong to + * @pool: pool the new worker will belong to * @bind: whether to set affinity to @cpu or not * - * Create a new worker which is bound to @gcwq. The returned worker + * Create a new worker which is bound to @pool. The returned worker * can be started by calling start_worker() or destroyed using * destroy_worker(). * @@ -1369,10 +1370,10 @@ static struct worker *alloc_worker(void) * RETURNS: * Pointer to the newly created worker. */ -static struct worker *create_worker(struct global_cwq *gcwq, bool bind) +static struct worker *create_worker(struct worker_pool *pool, bool bind) { + struct global_cwq *gcwq = pool->gcwq; bool on_unbound_cpu = gcwq->cpu == WORK_CPU_UNBOUND; - struct worker_pool *pool = &gcwq->pool; struct worker *worker = NULL; int id = -1; @@ -1480,27 +1481,27 @@ static void destroy_worker(struct worker *worker) ida_remove(&pool->worker_ida, id); } -static void idle_worker_timeout(unsigned long __gcwq) +static void idle_worker_timeout(unsigned long __pool) { - struct global_cwq *gcwq = (void *)__gcwq; + struct worker_pool *pool = (void *)__pool; + struct global_cwq *gcwq = pool->gcwq; spin_lock_irq(&gcwq->lock); - if (too_many_workers(gcwq)) { + if (too_many_workers(pool)) { struct worker *worker; unsigned long expires; /* idle_list is kept in LIFO order, check the last one */ - worker = list_entry(gcwq->pool.idle_list.prev, struct worker, - entry); + worker = list_entry(pool->idle_list.prev, struct worker, entry); expires = worker->last_active + IDLE_WORKER_TIMEOUT; if (time_before(jiffies, expires)) - mod_timer(&gcwq->pool.idle_timer, expires); + mod_timer(&pool->idle_timer, expires); else { /* it's been idle for too long, wake up manager */ gcwq->flags |= GCWQ_MANAGE_WORKERS; - wake_up_worker(gcwq); + wake_up_worker(pool); } } @@ -1526,37 +1527,38 @@ static bool send_mayday(struct work_struct *work) return true; } -static void gcwq_mayday_timeout(unsigned long __gcwq) +static void gcwq_mayday_timeout(unsigned long __pool) { - struct global_cwq *gcwq = (void *)__gcwq; + struct worker_pool *pool = (void *)__pool; + struct global_cwq *gcwq = pool->gcwq; struct work_struct *work; spin_lock_irq(&gcwq->lock); - if (need_to_create_worker(gcwq)) { + if (need_to_create_worker(pool)) { /* * We've been trying to create a new worker but * haven't been successful. We might be hitting an * allocation deadlock. Send distress signals to * rescuers. */ - list_for_each_entry(work, &gcwq->pool.worklist, entry) + list_for_each_entry(work, &pool->worklist, entry) send_mayday(work); } spin_unlock_irq(&gcwq->lock); - mod_timer(&gcwq->pool.mayday_timer, jiffies + MAYDAY_INTERVAL); + mod_timer(&pool->mayday_timer, jiffies + MAYDAY_INTERVAL); } /** * maybe_create_worker - create a new worker if necessary - * @gcwq: gcwq to create a new worker for + * @pool: pool to create a new worker for * - * Create a new worker for @gcwq if necessary. @gcwq is guaranteed to + * Create a new worker for @pool if necessary. @pool is guaranteed to * have at least one idle worker on return from this function. If * creating a new worker takes longer than MAYDAY_INTERVAL, mayday is - * sent to all rescuers with works scheduled on @gcwq to resolve + * sent to all rescuers with works scheduled on @pool to resolve * possible allocation deadlock. * * On return, need_to_create_worker() is guaranteed to be false and @@ -1571,52 +1573,54 @@ static void gcwq_mayday_timeout(unsigned long __gcwq) * false if no action was taken and gcwq->lock stayed locked, true * otherwise. */ -static bool maybe_create_worker(struct global_cwq *gcwq) +static bool maybe_create_worker(struct worker_pool *pool) __releases(&gcwq->lock) __acquires(&gcwq->lock) { - if (!need_to_create_worker(gcwq)) + struct global_cwq *gcwq = pool->gcwq; + + if (!need_to_create_worker(pool)) return false; restart: spin_unlock_irq(&gcwq->lock); /* if we don't make progress in MAYDAY_INITIAL_TIMEOUT, call for help */ - mod_timer(&gcwq->pool.mayday_timer, jiffies + MAYDAY_INITIAL_TIMEOUT); + mod_timer(&pool->mayday_timer, jiffies + MAYDAY_INITIAL_TIMEOUT); while (true) { struct worker *worker; - worker = create_worker(gcwq, true); + worker = create_worker(pool, true); if (worker) { - del_timer_sync(&gcwq->pool.mayday_timer); + del_timer_sync(&pool->mayday_timer); spin_lock_irq(&gcwq->lock); start_worker(worker); - BUG_ON(need_to_create_worker(gcwq)); + BUG_ON(need_to_create_worker(pool)); return true; } - if (!need_to_create_worker(gcwq)) + if (!need_to_create_worker(pool)) break; __set_current_state(TASK_INTERRUPTIBLE); schedule_timeout(CREATE_COOLDOWN); - if (!need_to_create_worker(gcwq)) + if (!need_to_create_worker(pool)) break; } - del_timer_sync(&gcwq->pool.mayday_timer); + del_timer_sync(&pool->mayday_timer); spin_lock_irq(&gcwq->lock); - if (need_to_create_worker(gcwq)) + if (need_to_create_worker(pool)) goto restart; return true; } /** * maybe_destroy_worker - destroy workers which have been idle for a while - * @gcwq: gcwq to destroy workers for + * @pool: pool to destroy workers for * - * Destroy @gcwq workers which have been idle for longer than + * Destroy @pool workers which have been idle for longer than * IDLE_WORKER_TIMEOUT. * * LOCKING: @@ -1627,20 +1631,19 @@ restart: * false if no action was taken and gcwq->lock stayed locked, true * otherwise. */ -static bool maybe_destroy_workers(struct global_cwq *gcwq) +static bool maybe_destroy_workers(struct worker_pool *pool) { bool ret = false; - while (too_many_workers(gcwq)) { + while (too_many_workers(pool)) { struct worker *worker; unsigned long expires; - worker = list_entry(gcwq->pool.idle_list.prev, struct worker, - entry); + worker = list_entry(pool->idle_list.prev, struct worker, entry); expires = worker->last_active + IDLE_WORKER_TIMEOUT; if (time_before(jiffies, expires)) { - mod_timer(&gcwq->pool.idle_timer, expires); + mod_timer(&pool->idle_timer, expires); break; } @@ -1673,7 +1676,8 @@ static bool maybe_destroy_workers(struct global_cwq *gcwq) */ static bool manage_workers(struct worker *worker) { - struct global_cwq *gcwq = worker->pool->gcwq; + struct worker_pool *pool = worker->pool; + struct global_cwq *gcwq = pool->gcwq; bool ret = false; if (gcwq->flags & GCWQ_MANAGING_WORKERS) @@ -1686,8 +1690,8 @@ static bool manage_workers(struct worker *worker) * Destroy and then create so that may_start_working() is true * on return. */ - ret |= maybe_destroy_workers(gcwq); - ret |= maybe_create_worker(gcwq); + ret |= maybe_destroy_workers(pool); + ret |= maybe_create_worker(pool); gcwq->flags &= ~GCWQ_MANAGING_WORKERS; @@ -1746,7 +1750,7 @@ static void cwq_activate_first_delayed(struct cpu_workqueue_struct *cwq) { struct work_struct *work = list_first_entry(&cwq->delayed_works, struct work_struct, entry); - struct list_head *pos = gcwq_determine_ins_pos(cwq->pool->gcwq, cwq); + struct list_head *pos = pool_determine_ins_pos(cwq->pool, cwq); trace_workqueue_activate_work(work); move_linked_works(work, pos, NULL); @@ -1874,7 +1878,7 @@ __acquires(&gcwq->lock) if (!list_empty(&pool->worklist) && get_work_cwq(nwork)->wq->flags & WQ_HIGHPRI) - wake_up_worker(gcwq); + wake_up_worker(pool); else gcwq->flags &= ~GCWQ_HIGHPRI_PENDING; } @@ -1890,8 +1894,8 @@ __acquires(&gcwq->lock) * Unbound gcwq isn't concurrency managed and work items should be * executed ASAP. Wake up another worker if necessary. */ - if ((worker->flags & WORKER_UNBOUND) && need_more_worker(gcwq)) - wake_up_worker(gcwq); + if ((worker->flags & WORKER_UNBOUND) && need_more_worker(pool)) + wake_up_worker(pool); spin_unlock_irq(&gcwq->lock); @@ -1983,11 +1987,11 @@ woke_up: worker_leave_idle(worker); recheck: /* no more worker necessary? */ - if (!need_more_worker(gcwq)) + if (!need_more_worker(pool)) goto sleep; /* do we need to manage? */ - if (unlikely(!may_start_working(gcwq)) && manage_workers(worker)) + if (unlikely(!may_start_working(pool)) && manage_workers(worker)) goto recheck; /* @@ -2018,11 +2022,11 @@ recheck: move_linked_works(work, &worker->scheduled, NULL); process_scheduled_works(worker); } - } while (keep_working(gcwq)); + } while (keep_working(pool)); worker_set_flags(worker, WORKER_PREP, false); sleep: - if (unlikely(need_to_manage_workers(gcwq)) && manage_workers(worker)) + if (unlikely(need_to_manage_workers(pool)) && manage_workers(worker)) goto recheck; /* @@ -2107,8 +2111,8 @@ repeat: * regular worker; otherwise, we end up with 0 concurrency * and stalling the execution. */ - if (keep_working(gcwq)) - wake_up_worker(gcwq); + if (keep_working(pool)) + wake_up_worker(pool); spin_unlock_irq(&gcwq->lock); } @@ -3383,7 +3387,7 @@ static int __cpuinit trustee_thread(void *__gcwq) * keep_working() are always true as long as the worklist is * not empty. */ - atomic_set(get_gcwq_nr_running(gcwq->cpu), 0); + atomic_set(get_pool_nr_running(&gcwq->pool), 0); spin_unlock_irq(&gcwq->lock); del_timer_sync(&gcwq->pool.idle_timer); @@ -3424,9 +3428,9 @@ static int __cpuinit trustee_thread(void *__gcwq) wake_up_process(worker->task); } - if (need_to_create_worker(gcwq)) { + if (need_to_create_worker(&gcwq->pool)) { spin_unlock_irq(&gcwq->lock); - worker = create_worker(gcwq, false); + worker = create_worker(&gcwq->pool, false); spin_lock_irq(&gcwq->lock); if (worker) { worker->flags |= WORKER_ROGUE; @@ -3540,7 +3544,7 @@ static int __devinit workqueue_cpu_callback(struct notifier_block *nfb, /* fall through */ case CPU_UP_PREPARE: BUG_ON(gcwq->pool.first_idle); - new_worker = create_worker(gcwq, false); + new_worker = create_worker(&gcwq->pool, false); if (!new_worker) { if (new_trustee) kthread_stop(new_trustee); @@ -3788,7 +3792,7 @@ void thaw_workqueues(void) cwq_activate_first_delayed(cwq); } - wake_up_worker(gcwq); + wake_up_worker(&gcwq->pool); spin_unlock_irq(&gcwq->lock); } @@ -3822,10 +3826,10 @@ static int __init init_workqueues(void) init_timer_deferrable(&gcwq->pool.idle_timer); gcwq->pool.idle_timer.function = idle_worker_timeout; - gcwq->pool.idle_timer.data = (unsigned long)gcwq; + gcwq->pool.idle_timer.data = (unsigned long)&gcwq->pool; setup_timer(&gcwq->pool.mayday_timer, gcwq_mayday_timeout, - (unsigned long)gcwq); + (unsigned long)&gcwq->pool); ida_init(&gcwq->pool.worker_ida); @@ -3840,7 +3844,7 @@ static int __init init_workqueues(void) if (cpu != WORK_CPU_UNBOUND) gcwq->flags &= ~GCWQ_DISASSOCIATED; - worker = create_worker(gcwq, true); + worker = create_worker(&gcwq->pool, true); BUG_ON(!worker); spin_lock_irq(&gcwq->lock); start_worker(worker); -- 2.39.5