* be executing on any CPU. The gcwq behaves as an unbound one.
*
* Note that DISASSOCIATED can be flipped only while holding
- * managership of all pools on the gcwq to avoid changing binding
+ * assoc_mutex of all pools on the gcwq to avoid changing binding
* state while create_worker() is in progress.
*/
GCWQ_DISASSOCIATED = 1 << 0, /* cpu can't serve workers */
WORKER_DIE = 1 << 1, /* die die die */
WORKER_IDLE = 1 << 2, /* is idle */
WORKER_PREP = 1 << 3, /* preparing to run works */
- WORKER_REBIND = 1 << 5, /* mom is home, come back */
WORKER_CPU_INTENSIVE = 1 << 6, /* cpu intensive */
WORKER_UNBOUND = 1 << 7, /* worker is unbound */
- WORKER_NOT_RUNNING = WORKER_PREP | WORKER_REBIND | WORKER_UNBOUND |
+ WORKER_NOT_RUNNING = WORKER_PREP | WORKER_UNBOUND |
WORKER_CPU_INTENSIVE,
NR_WORKER_POOLS = 2, /* # worker pools per gcwq */
struct timer_list idle_timer; /* L: worker idle timeout */
struct timer_list mayday_timer; /* L: SOS timer for workers */
- struct mutex manager_mutex; /* mutex manager should hold */
+ struct mutex assoc_mutex; /* protect GCWQ_DISASSOCIATED */
struct ida worker_ida; /* L: for worker IDs */
};
/*
* Rebind an idle @worker to its CPU. worker_thread() will test
- * %WORKER_REBIND before leaving idle and call this function.
+ * list_empty(@worker->entry) before leaving idle and call this function.
*/
static void idle_worker_rebind(struct worker *worker)
{
struct global_cwq *gcwq = worker->pool->gcwq;
- /*
- * CPU may go down again inbetween. If rebinding fails, reinstate
- * UNBOUND. We're off idle_list and nobody else can do it for us.
- */
- if (!worker_maybe_bind_and_lock(worker))
- worker->flags |= WORKER_UNBOUND;
-
- worker_clr_flags(worker, WORKER_REBIND);
+ /* CPU may go down again inbetween, clear UNBOUND only on success */
+ if (worker_maybe_bind_and_lock(worker))
+ worker_clr_flags(worker, WORKER_UNBOUND);
/* rebind complete, become available again */
list_add(&worker->entry, &worker->pool->idle_list);
struct worker *worker = container_of(work, struct worker, rebind_work);
struct global_cwq *gcwq = worker->pool->gcwq;
- worker_maybe_bind_and_lock(worker);
-
- /*
- * %WORKER_REBIND must be cleared even if the above binding failed;
- * otherwise, we may confuse the next CPU_UP cycle or oops / get
- * stuck by calling idle_worker_rebind() prematurely. If CPU went
- * down again inbetween, %WORKER_UNBOUND would be set, so clearing
- * %WORKER_REBIND is always safe.
- */
- worker_clr_flags(worker, WORKER_REBIND);
+ if (worker_maybe_bind_and_lock(worker))
+ worker_clr_flags(worker, WORKER_UNBOUND);
spin_unlock_irq(&gcwq->lock);
}
lockdep_assert_held(&gcwq->lock);
for_each_worker_pool(pool, gcwq)
- lockdep_assert_held(&pool->manager_mutex);
+ lockdep_assert_held(&pool->assoc_mutex);
- /* set REBIND and kick idle ones */
+ /* dequeue and kick idle ones */
for_each_worker_pool(pool, gcwq) {
list_for_each_entry_safe(worker, n, &pool->idle_list, entry) {
- unsigned long worker_flags = worker->flags;
-
- /* morph UNBOUND to REBIND atomically */
- worker_flags &= ~WORKER_UNBOUND;
- worker_flags |= WORKER_REBIND;
- ACCESS_ONCE(worker->flags) = worker_flags;
-
/*
* idle workers should be off @pool->idle_list
* until rebind is complete to avoid receiving
*/
list_del_init(&worker->entry);
- /* worker_thread() will call idle_worker_rebind() */
+ /*
+ * worker_thread() will see the above dequeuing
+ * and call idle_worker_rebind().
+ */
wake_up_process(worker->task);
}
}
/* rebind busy workers */
for_each_busy_worker(worker, i, pos, gcwq) {
- unsigned long worker_flags = worker->flags;
struct work_struct *rebind_work = &worker->rebind_work;
struct workqueue_struct *wq;
- /* morph UNBOUND to REBIND atomically */
- worker_flags &= ~WORKER_UNBOUND;
- worker_flags |= WORKER_REBIND;
- ACCESS_ONCE(worker->flags) = worker_flags;
-
if (test_and_set_bit(WORK_STRUCT_PENDING_BIT,
work_data_bits(rebind_work)))
continue;
* grab %POOL_MANAGING_WORKERS to achieve this because that can
* lead to idle worker depletion (all become busy thinking someone
* else is managing) which in turn can result in deadlock under
- * extreme circumstances. Use @pool->manager_mutex to synchronize
+ * extreme circumstances. Use @pool->assoc_mutex to synchronize
* manager against CPU hotplug.
*
- * manager_mutex would always be free unless CPU hotplug is in
+ * assoc_mutex would always be free unless CPU hotplug is in
* progress. trylock first without dropping @gcwq->lock.
*/
- if (unlikely(!mutex_trylock(&pool->manager_mutex))) {
+ if (unlikely(!mutex_trylock(&pool->assoc_mutex))) {
spin_unlock_irq(&pool->gcwq->lock);
- mutex_lock(&pool->manager_mutex);
+ mutex_lock(&pool->assoc_mutex);
/*
* CPU hotplug could have happened while we were waiting
- * for manager_mutex. Hotplug itself can't handle us
+ * for assoc_mutex. Hotplug itself can't handle us
* because manager isn't either on idle or busy list, and
* @gcwq's state and ours could have deviated.
*
- * As hotplug is now excluded via manager_mutex, we can
+ * As hotplug is now excluded via assoc_mutex, we can
* simply try to bind. It will succeed or fail depending
* on @gcwq's current state. Try it and adjust
* %WORKER_UNBOUND accordingly.
ret |= maybe_create_worker(pool);
pool->flags &= ~POOL_MANAGING_WORKERS;
- mutex_unlock(&pool->manager_mutex);
+ mutex_unlock(&pool->assoc_mutex);
return ret;
}
* necessary to avoid spurious warnings from rescuers servicing the
* unbound or a disassociated gcwq.
*/
- WARN_ON_ONCE(!(worker->flags & (WORKER_UNBOUND | WORKER_REBIND)) &&
+ WARN_ON_ONCE(!(worker->flags & WORKER_UNBOUND) &&
!(gcwq->flags & GCWQ_DISASSOCIATED) &&
raw_smp_processor_id() != gcwq->cpu);
woke_up:
spin_lock_irq(&gcwq->lock);
- /*
- * DIE can be set only while idle and REBIND set while busy has
- * @worker->rebind_work scheduled. Checking here is enough.
- */
- if (unlikely(worker->flags & (WORKER_REBIND | WORKER_DIE))) {
+ /* we are off idle list if destruction or rebind is requested */
+ if (unlikely(list_empty(&worker->entry))) {
spin_unlock_irq(&gcwq->lock);
+ /* if DIE is set, destruction is requested */
if (worker->flags & WORKER_DIE) {
worker->task->flags &= ~PF_WQ_WORKER;
return 0;
}
+ /* otherwise, rebind */
idle_worker_rebind(worker);
goto woke_up;
}
*/
/* claim manager positions of all pools */
-static void gcwq_claim_management_and_lock(struct global_cwq *gcwq)
+static void gcwq_claim_assoc_and_lock(struct global_cwq *gcwq)
{
struct worker_pool *pool;
for_each_worker_pool(pool, gcwq)
- mutex_lock_nested(&pool->manager_mutex, pool - gcwq->pools);
+ mutex_lock_nested(&pool->assoc_mutex, pool - gcwq->pools);
spin_lock_irq(&gcwq->lock);
}
/* release manager positions */
-static void gcwq_release_management_and_unlock(struct global_cwq *gcwq)
+static void gcwq_release_assoc_and_unlock(struct global_cwq *gcwq)
{
struct worker_pool *pool;
spin_unlock_irq(&gcwq->lock);
for_each_worker_pool(pool, gcwq)
- mutex_unlock(&pool->manager_mutex);
+ mutex_unlock(&pool->assoc_mutex);
}
static void gcwq_unbind_fn(struct work_struct *work)
BUG_ON(gcwq->cpu != smp_processor_id());
- gcwq_claim_management_and_lock(gcwq);
+ gcwq_claim_assoc_and_lock(gcwq);
/*
* We've claimed all manager positions. Make all workers unbound
gcwq->flags |= GCWQ_DISASSOCIATED;
- gcwq_release_management_and_unlock(gcwq);
+ gcwq_release_assoc_and_unlock(gcwq);
/*
* Call schedule() so that we cross rq->lock and thus can guarantee
* Workqueues should be brought up before normal priority CPU notifiers.
* This will be registered high priority CPU notifier.
*/
-static int __devinit workqueue_cpu_up_callback(struct notifier_block *nfb,
+static int __cpuinit workqueue_cpu_up_callback(struct notifier_block *nfb,
unsigned long action,
void *hcpu)
{
case CPU_DOWN_FAILED:
case CPU_ONLINE:
- gcwq_claim_management_and_lock(gcwq);
+ gcwq_claim_assoc_and_lock(gcwq);
gcwq->flags &= ~GCWQ_DISASSOCIATED;
rebind_workers(gcwq);
- gcwq_release_management_and_unlock(gcwq);
+ gcwq_release_assoc_and_unlock(gcwq);
break;
}
return NOTIFY_OK;
* Workqueues should be brought down after normal priority CPU notifiers.
* This will be registered as low priority CPU notifier.
*/
-static int __devinit workqueue_cpu_down_callback(struct notifier_block *nfb,
+static int __cpuinit workqueue_cpu_down_callback(struct notifier_block *nfb,
unsigned long action,
void *hcpu)
{
setup_timer(&pool->mayday_timer, gcwq_mayday_timeout,
(unsigned long)pool);
- mutex_init(&pool->manager_mutex);
+ mutex_init(&pool->assoc_mutex);
ida_init(&pool->worker_ida);
}
}
projects / GitHub / mt8127 / android_kernel_alcatel_ttab.git / blobdiff