workqueue: replace for_each_worker_pool() with for_each_std_worker_pool()

for_each_std_worker_pool() takes @cpu instead of @gcwq.

This is part of an effort to remove global_cwq and make worker_pool
the top level abstraction, which in turn will help implementing worker
pools with user-specified attributes.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Lai Jiangshan <laijs@cn.fujitsu.com>

kernel/workqueue.c

@@ -250,9 +250,9 @@ EXPORT_SYMBOL_GPL(system_freezable_wq);
 #define CREATE_TRACE_POINTS
 #include <trace/events/workqueue.h>
 
-#define for_each_worker_pool(pool, gcwq)				\
-	for ((pool) = &(gcwq)->pools[0];				\
-	     (pool) < &(gcwq)->pools[NR_STD_WORKER_POOLS]; (pool)++)
+#define for_each_std_worker_pool(pool, cpu)				\
+	for ((pool) = &get_gcwq((cpu))->pools[0];			\
+	     (pool) < &get_gcwq((cpu))->pools[NR_STD_WORKER_POOLS]; (pool)++)
 
 #define for_each_busy_worker(worker, i, pos, pool)			\
 	hash_for_each(pool->busy_hash, i, pos, worker, hentry)
@@ -3500,14 +3500,14 @@ EXPORT_SYMBOL_GPL(work_busy);
 
 static void gcwq_unbind_fn(struct work_struct *work)
 {
-	struct global_cwq *gcwq = get_gcwq(smp_processor_id());
+	int cpu = smp_processor_id();
 	struct worker_pool *pool;
 	struct worker *worker;
 	struct hlist_node *pos;
 	int i;
 
-	for_each_worker_pool(pool, gcwq) {
-		BUG_ON(pool->cpu != smp_processor_id());
+	for_each_std_worker_pool(pool, cpu) {
+		BUG_ON(cpu != smp_processor_id());
 
 		mutex_lock(&pool->assoc_mutex);
 		spin_lock_irq(&pool->lock);
@@ -3541,15 +3541,15 @@ static void gcwq_unbind_fn(struct work_struct *work)
 	/*
 	 * Sched callbacks are disabled now.  Zap nr_running.  After this,
 	 * nr_running stays zero and need_more_worker() and keep_working()
-	 * are always true as long as the worklist is not empty.  @gcwq now
-	 * behaves as unbound (in terms of concurrency management) gcwq
-	 * which is served by workers tied to the CPU.
+	 * are always true as long as the worklist is not empty.  Pools on
+	 * @cpu now behave as unbound (in terms of concurrency management)
+	 * pools which are served by workers tied to the CPU.
 	 *
 	 * On return from this function, the current worker would trigger
 	 * unbound chain execution of pending work items if other workers
 	 * didn't already.
 	 */
-	for_each_worker_pool(pool, gcwq)
+	for_each_std_worker_pool(pool, cpu)
 		atomic_set(get_pool_nr_running(pool), 0);
 }
 
@@ -3562,12 +3562,11 @@ static int __cpuinit workqueue_cpu_up_callback(struct notifier_block *nfb,
 					       void *hcpu)
 {
 	unsigned int cpu = (unsigned long)hcpu;
-	struct global_cwq *gcwq = get_gcwq(cpu);
 	struct worker_pool *pool;
 
 	switch (action & ~CPU_TASKS_FROZEN) {
 	case CPU_UP_PREPARE:
-		for_each_worker_pool(pool, gcwq) {
+		for_each_std_worker_pool(pool, cpu) {
 			struct worker *worker;
 
 			if (pool->nr_workers)
@@ -3585,7 +3584,7 @@ static int __cpuinit workqueue_cpu_up_callback(struct notifier_block *nfb,
 
 	case CPU_DOWN_FAILED:
 	case CPU_ONLINE:
-		for_each_worker_pool(pool, gcwq) {
+		for_each_std_worker_pool(pool, cpu) {
 			mutex_lock(&pool->assoc_mutex);
 			spin_lock_irq(&pool->lock);
 
@@ -3682,11 +3681,10 @@ void freeze_workqueues_begin(void)
 	workqueue_freezing = true;
 
 	for_each_gcwq_cpu(cpu) {
-		struct global_cwq *gcwq = get_gcwq(cpu);
 		struct worker_pool *pool;
 		struct workqueue_struct *wq;
 
-		for_each_worker_pool(pool, gcwq) {
+		for_each_std_worker_pool(pool, cpu) {
 			spin_lock_irq(&pool->lock);
 
 			WARN_ON_ONCE(pool->flags & POOL_FREEZING);
@@ -3772,11 +3770,10 @@ void thaw_workqueues(void)
 		goto out_unlock;
 
 	for_each_gcwq_cpu(cpu) {
-		struct global_cwq *gcwq = get_gcwq(cpu);
 		struct worker_pool *pool;
 		struct workqueue_struct *wq;
 
-		for_each_worker_pool(pool, gcwq) {
+		for_each_std_worker_pool(pool, cpu) {
 			spin_lock_irq(&pool->lock);
 
 			WARN_ON_ONCE(!(pool->flags & POOL_FREEZING));
@@ -3818,11 +3815,10 @@ static int __init init_workqueues(void)
 
 	/* initialize gcwqs */
 	for_each_gcwq_cpu(cpu) {
-		struct global_cwq *gcwq = get_gcwq(cpu);
 		struct worker_pool *pool;
 
-		for_each_worker_pool(pool, gcwq) {
-			pool->gcwq = gcwq;
+		for_each_std_worker_pool(pool, cpu) {
+			pool->gcwq = get_gcwq(cpu);
 			spin_lock_init(&pool->lock);
 			pool->cpu = cpu;
 			pool->flags |= POOL_DISASSOCIATED;
@@ -3847,10 +3843,9 @@ static int __init init_workqueues(void)
 
 	/* create the initial worker */
 	for_each_online_gcwq_cpu(cpu) {
-		struct global_cwq *gcwq = get_gcwq(cpu);
 		struct worker_pool *pool;
 
-		for_each_worker_pool(pool, gcwq) {
+		for_each_std_worker_pool(pool, cpu) {
 			struct worker *worker;
 
 			if (cpu != WORK_CPU_UNBOUND)