workqueue: separate out worker_pool flags

GCWQ_MANAGE_WORKERS, GCWQ_MANAGING_WORKERS and GCWQ_HIGHPRI_PENDING
are per-pool properties.  Add worker_pool->flags and make the above
three flags per-pool flags.

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>

kernel/workqueue.c

@@ -46,11 +46,13 @@
 
 enum {
 	/* global_cwq flags */
-	GCWQ_MANAGE_WORKERS	= 1 << 0,	/* need to manage workers */
-	GCWQ_MANAGING_WORKERS	= 1 << 1,	/* managing workers */
-	GCWQ_DISASSOCIATED	= 1 << 2,	/* cpu can't serve workers */
-	GCWQ_FREEZING		= 1 << 3,	/* freeze in progress */
-	GCWQ_HIGHPRI_PENDING	= 1 << 4,	/* highpri works on queue */
+	GCWQ_DISASSOCIATED	= 1 << 0,	/* cpu can't serve workers */
+	GCWQ_FREEZING		= 1 << 1,	/* freeze in progress */
+
+	/* pool flags */
+	POOL_MANAGE_WORKERS	= 1 << 0,	/* need to manage workers */
+	POOL_MANAGING_WORKERS	= 1 << 1,	/* managing workers */
+	POOL_HIGHPRI_PENDING	= 1 << 2,	/* highpri works on queue */
 
 	/* worker flags */
 	WORKER_STARTED		= 1 << 0,	/* started */
@@ -142,6 +144,7 @@ struct worker {
 
 struct worker_pool {
 	struct global_cwq	*gcwq;		/* I: the owning gcwq */
+	unsigned int		flags;		/* X: flags */
 
 	struct list_head	worklist;	/* L: list of pending works */
 	int			nr_workers;	/* L: total number of workers */
@@ -583,7 +586,7 @@ static struct global_cwq *get_work_gcwq(struct work_struct *work)
 static bool __need_more_worker(struct worker_pool *pool)
 {
 	return !atomic_read(get_pool_nr_running(pool)) ||
-		pool->gcwq->flags & GCWQ_HIGHPRI_PENDING;
+		(pool->flags & POOL_HIGHPRI_PENDING);
 }
 
 /*
@@ -612,7 +615,7 @@ static bool keep_working(struct worker_pool *pool)
 
 	return !list_empty(&pool->worklist) &&
 		(atomic_read(nr_running) <= 1 ||
-		 pool->gcwq->flags & GCWQ_HIGHPRI_PENDING);
+		 (pool->flags & POOL_HIGHPRI_PENDING));
 }
 
 /* Do we need a new worker?  Called from manager. */
@@ -625,13 +628,13 @@ static bool need_to_create_worker(struct worker_pool *pool)
 static bool need_to_manage_workers(struct worker_pool *pool)
 {
 	return need_to_create_worker(pool) ||
-		pool->gcwq->flags & GCWQ_MANAGE_WORKERS;
+		(pool->flags & POOL_MANAGE_WORKERS);
 }
 
 /* Do we have too many workers and should some go away? */
 static bool too_many_workers(struct worker_pool *pool)
 {
-	bool managing = pool->gcwq->flags & GCWQ_MANAGING_WORKERS;
+	bool managing = pool->flags & POOL_MANAGING_WORKERS;
 	int nr_idle = pool->nr_idle + managing; /* manager is considered idle */
 	int nr_busy = pool->nr_workers - nr_idle;
 
@@ -889,7 +892,7 @@ static struct worker *find_worker_executing_work(struct global_cwq *gcwq,
  * 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 @pool that
+ * function also sets POOL_HIGHPRI_PENDING flag to hint @pool that
  * there are HIGHPRI works pending.
  *
  * CONTEXT:
@@ -913,7 +916,7 @@ static inline struct list_head *pool_determine_ins_pos(struct worker_pool *pool,
 			break;
 	}
 
-	pool->gcwq->flags |= GCWQ_HIGHPRI_PENDING;
+	pool->flags |= POOL_HIGHPRI_PENDING;
 	return &twork->entry;
 }
 
@@ -1500,7 +1503,7 @@ static void idle_worker_timeout(unsigned long __pool)
 			mod_timer(&pool->idle_timer, expires);
 		else {
 			/* it's been idle for too long, wake up manager */
-			gcwq->flags |= GCWQ_MANAGE_WORKERS;
+			pool->flags |= POOL_MANAGE_WORKERS;
 			wake_up_worker(pool);
 		}
 	}
@@ -1680,11 +1683,11 @@ static bool manage_workers(struct worker *worker)
 	struct global_cwq *gcwq = pool->gcwq;
 	bool ret = false;
 
-	if (gcwq->flags & GCWQ_MANAGING_WORKERS)
+	if (pool->flags & POOL_MANAGING_WORKERS)
 		return ret;
 
-	gcwq->flags &= ~GCWQ_MANAGE_WORKERS;
-	gcwq->flags |= GCWQ_MANAGING_WORKERS;
+	pool->flags &= ~POOL_MANAGE_WORKERS;
+	pool->flags |= POOL_MANAGING_WORKERS;
 
 	/*
 	 * Destroy and then create so that may_start_working() is true
@@ -1693,7 +1696,7 @@ static bool manage_workers(struct worker *worker)
 	ret |= maybe_destroy_workers(pool);
 	ret |= maybe_create_worker(pool);
 
-	gcwq->flags &= ~GCWQ_MANAGING_WORKERS;
+	pool->flags &= ~POOL_MANAGING_WORKERS;
 
 	/*
 	 * The trustee might be waiting to take over the manager
@@ -1872,7 +1875,7 @@ __acquires(&gcwq->lock)
 	 * If HIGHPRI_PENDING, check the next work, and, if HIGHPRI,
 	 * wake up another worker; otherwise, clear HIGHPRI_PENDING.
 	 */
-	if (unlikely(gcwq->flags & GCWQ_HIGHPRI_PENDING)) {
+	if (unlikely(pool->flags & POOL_HIGHPRI_PENDING)) {
 		struct work_struct *nwork = list_first_entry(&pool->worklist,
 					 struct work_struct, entry);
 
@@ -1880,7 +1883,7 @@ __acquires(&gcwq->lock)
 		    get_work_cwq(nwork)->wq->flags & WQ_HIGHPRI)
 			wake_up_worker(pool);
 		else
-			gcwq->flags &= ~GCWQ_HIGHPRI_PENDING;
+			pool->flags &= ~POOL_HIGHPRI_PENDING;
 	}
 
 	/*
@@ -3360,10 +3363,10 @@ static int __cpuinit trustee_thread(void *__gcwq)
 	 * cancelled.
 	 */
 	BUG_ON(gcwq->cpu != smp_processor_id());
-	rc = trustee_wait_event(!(gcwq->flags & GCWQ_MANAGING_WORKERS));
+	rc = trustee_wait_event(!(gcwq->pool.flags & POOL_MANAGING_WORKERS));
 	BUG_ON(rc < 0);
 
-	gcwq->flags |= GCWQ_MANAGING_WORKERS;
+	gcwq->pool.flags |= POOL_MANAGING_WORKERS;
 
 	list_for_each_entry(worker, &gcwq->pool.idle_list, entry)
 		worker->flags |= WORKER_ROGUE;
@@ -3487,7 +3490,7 @@ static int __cpuinit trustee_thread(void *__gcwq)
 	}
 
 	/* relinquish manager role */
-	gcwq->flags &= ~GCWQ_MANAGING_WORKERS;
+	gcwq->pool.flags &= ~POOL_MANAGING_WORKERS;
 
 	/* notify completion */
 	gcwq->trustee = NULL;
@@ -3604,7 +3607,7 @@ static int __devinit workqueue_cpu_callback(struct notifier_block *nfb,
 		spin_unlock_irq(&gcwq->lock);
 		kthread_bind(gcwq->pool.first_idle->task, cpu);
 		spin_lock_irq(&gcwq->lock);
-		gcwq->flags |= GCWQ_MANAGE_WORKERS;
+		gcwq->pool.flags |= POOL_MANAGE_WORKERS;
 		start_worker(gcwq->pool.first_idle);
 		gcwq->pool.first_idle = NULL;
 		break;