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workqueue: use @pool instead of @gcwq or @cpu where applicable

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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 <tj@kernel.org>
This commit is contained in:
Tejun Heo 2012-07-12 14:46:37 -07:00
parent bd7bdd43dc
commit 63d95a9150
1 changed files with 111 additions and 107 deletions
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218
kernel/workqueue.c
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@ -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);