Commit 7a62c2c8 authored by Tejun Heo's avatar Tejun Heo
Browse files

workqueue: remove unbound_std_worker_pools[] and related helpers 



Workqueue no longer makes use of unbound_std_worker_pools[].  All
unbound worker_pools are created dynamically and there's nothing
special about the standard ones.  With unbound_std_worker_pools[]
unused, workqueue no longer has places where it needs to treat the
per-cpu pools-cpu and unbound pools together.

Remove unbound_std_worker_pools[] and the helpers wrapping it to
present unified per-cpu and unbound standard worker_pools.

* for_each_std_worker_pool() now only walks through per-cpu pools.

* for_each[_online]_wq_cpu() which don't have any users left are
  removed.

* std_worker_pools() and std_worker_pool_pri() are unused and removed.

* get_std_worker_pool() is removed.  Its only user -
  alloc_and_link_pwqs() - only used it for per-cpu pools anyway.  Open
  code per_cpu access in alloc_and_link_pwqs() instead.

This patch doesn't introduce any functional changes.

Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Reviewed-by: default avatarLai Jiangshan <laijs@cn.fujitsu.com>
parent 29c91e99

kernel/workqueue.c

+6 −60
Original line number Diff line number Diff line
@@ -253,48 +253,13 @@ EXPORT_SYMBOL_GPL(system_freezable_wq); 
			   "sched RCU or workqueue lock should be held")



#define for_each_std_worker_pool(pool, cpu)				\

	for ((pool) = &std_worker_pools(cpu)[0];			\

	     (pool) < &std_worker_pools(cpu)[NR_STD_WORKER_POOLS]; (pool)++)

	for ((pool) = &per_cpu(cpu_std_worker_pools, cpu)[0];		\

	     (pool) < &per_cpu(cpu_std_worker_pools, cpu)[NR_STD_WORKER_POOLS]; \

	     (pool)++)



#define for_each_busy_worker(worker, i, pool)				\

	hash_for_each(pool->busy_hash, i, worker, hentry)



static inline int __next_wq_cpu(int cpu, const struct cpumask *mask,

				unsigned int sw)

{

	if (cpu < nr_cpu_ids) {

		if (sw & 1) {

			cpu = cpumask_next(cpu, mask);

			if (cpu < nr_cpu_ids)

				return cpu;

		}

		if (sw & 2)

			return WORK_CPU_UNBOUND;

	}

	return WORK_CPU_END;

}



/*

 * CPU iterators

 *

 * An extra cpu number is defined using an invalid cpu number

 * (WORK_CPU_UNBOUND) to host workqueues which are not bound to any

 * specific CPU.  The following iterators are similar to for_each_*_cpu()

 * iterators but also considers the unbound CPU.

 *

 * for_each_wq_cpu()		: possible CPUs + WORK_CPU_UNBOUND

 * for_each_online_wq_cpu()	: online CPUs + WORK_CPU_UNBOUND

 */

#define for_each_wq_cpu(cpu)						\

	for ((cpu) = __next_wq_cpu(-1, cpu_possible_mask, 3);		\

	     (cpu) < WORK_CPU_END;					\

	     (cpu) = __next_wq_cpu((cpu), cpu_possible_mask, 3))



#define for_each_online_wq_cpu(cpu)					\

	for ((cpu) = __next_wq_cpu(-1, cpu_online_mask, 3);		\

	     (cpu) < WORK_CPU_END;					\

	     (cpu) = __next_wq_cpu((cpu), cpu_online_mask, 3))



/**

 * for_each_pool - iterate through all worker_pools in the system

 * @pool: iteration cursor
@@ -456,7 +421,6 @@ static bool workqueue_freezing; /* W: have wqs started freezing? */ 
 */

static DEFINE_PER_CPU_SHARED_ALIGNED(struct worker_pool [NR_STD_WORKER_POOLS],

				     cpu_std_worker_pools);

static struct worker_pool unbound_std_worker_pools[NR_STD_WORKER_POOLS];



/*

 * idr of all pools.  Modifications are protected by workqueue_lock.  Read
@@ -466,19 +430,6 @@ static DEFINE_IDR(worker_pool_idr); 


static int worker_thread(void *__worker);



static struct worker_pool *std_worker_pools(int cpu)

{

	if (cpu != WORK_CPU_UNBOUND)

		return per_cpu(cpu_std_worker_pools, cpu);

	else

		return unbound_std_worker_pools;

}



static int std_worker_pool_pri(struct worker_pool *pool)

{

	return pool - std_worker_pools(pool->cpu);

}



/* allocate ID and assign it to @pool */

static int worker_pool_assign_id(struct worker_pool *pool)

{
@@ -496,13 +447,6 @@ static int worker_pool_assign_id(struct worker_pool *pool) 
	return ret;

}



static struct worker_pool *get_std_worker_pool(int cpu, bool highpri)

{

	struct worker_pool *pools = std_worker_pools(cpu);



	return &pools[highpri];

}



/**

 * first_pwq - return the first pool_workqueue of the specified workqueue

 * @wq: the target workqueue
@@ -3397,8 +3341,10 @@ static int alloc_and_link_pwqs(struct workqueue_struct *wq) 
		for_each_possible_cpu(cpu) {

			struct pool_workqueue *pwq =

				per_cpu_ptr(wq->cpu_pwqs, cpu);

			struct worker_pool *cpu_pools =

				per_cpu(cpu_std_worker_pools, cpu);



			pwq->pool = get_std_worker_pool(cpu, highpri);

			pwq->pool = &cpu_pools[highpri];

			list_add_tail_rcu(&pwq->pwqs_node, &wq->pwqs);

		}

	} else {

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