From 7cda9aae0596d871a8d7a6888d7b447c60e5ab30 Mon Sep 17 00:00:00 2001 From: Lai Jiangshan Date: Tue, 20 May 2014 17:46:32 +0800 Subject: workqueue: convert worker_idr to worker_ida We no longer iterate workers via worker_idr and worker_idr is used only for allocating/freeing ID, so we can convert it to worker_ida. By using ida_simple_get/remove(), worker_ida doesn't require external synchronization, so we don't need manager_mutex to protect it and the ID-removal code is allowed to be moved out from worker_detach_from_pool(). In a later patch, worker_detach_from_pool() will be used in rescuers which don't have IDs, so we move the ID-removal code out from worker_detach_from_pool() into worker_thread(). tj: Minor description updates. Signed-off-by: Lai Jiangshan Signed-off-by: Tejun Heo --- kernel/workqueue.c | 20 ++++++++------------ 1 file changed, 8 insertions(+), 12 deletions(-) (limited to 'kernel/workqueue.c') diff --git a/kernel/workqueue.c b/kernel/workqueue.c index a6c38b717957..092f2098746d 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -161,10 +161,11 @@ struct worker_pool { /* see manage_workers() for details on the two manager mutexes */ struct mutex manager_arb; /* manager arbitration */ struct mutex manager_mutex; /* manager exclusion */ - struct idr worker_idr; /* M: worker IDs */ struct list_head workers; /* M: attached workers */ struct completion *detach_completion; /* all workers detached */ + struct ida worker_ida; /* worker IDs for task name */ + struct workqueue_attrs *attrs; /* I: worker attributes */ struct hlist_node hash_node; /* PL: unbound_pool_hash node */ int refcnt; /* PL: refcnt for unbound pools */ @@ -1696,7 +1697,6 @@ static void worker_detach_from_pool(struct worker *worker, struct completion *detach_completion = NULL; mutex_lock(&pool->manager_mutex); - idr_remove(&pool->worker_idr, worker->id); list_del(&worker->node); if (list_empty(&pool->workers)) detach_completion = pool->detach_completion; @@ -1727,11 +1727,8 @@ static struct worker *create_worker(struct worker_pool *pool) lockdep_assert_held(&pool->manager_mutex); - /* - * ID is needed to determine kthread name. Allocate ID first - * without installing the pointer. - */ - id = idr_alloc(&pool->worker_idr, NULL, 0, 0, GFP_KERNEL); + /* ID is needed to determine kthread name */ + id = ida_simple_get(&pool->worker_ida, 0, 0, GFP_KERNEL); if (id < 0) goto fail; @@ -1772,8 +1769,6 @@ static struct worker *create_worker(struct worker_pool *pool) if (pool->flags & POOL_DISASSOCIATED) worker->flags |= WORKER_UNBOUND; - /* successful, commit the pointer to idr */ - idr_replace(&pool->worker_idr, worker, worker->id); /* successful, attach the worker to the pool */ list_add_tail(&worker->node, &pool->workers); @@ -1781,7 +1776,7 @@ static struct worker *create_worker(struct worker_pool *pool) fail: if (id >= 0) - idr_remove(&pool->worker_idr, id); + ida_simple_remove(&pool->worker_ida, id); kfree(worker); return NULL; } @@ -2250,6 +2245,7 @@ woke_up: worker->task->flags &= ~PF_WQ_WORKER; set_task_comm(worker->task, "kworker/dying"); + ida_simple_remove(&pool->worker_ida, worker->id); worker_detach_from_pool(worker, pool); kfree(worker); return 0; @@ -3486,9 +3482,9 @@ static int init_worker_pool(struct worker_pool *pool) mutex_init(&pool->manager_arb); mutex_init(&pool->manager_mutex); - idr_init(&pool->worker_idr); INIT_LIST_HEAD(&pool->workers); + ida_init(&pool->worker_ida); INIT_HLIST_NODE(&pool->hash_node); pool->refcnt = 1; @@ -3503,7 +3499,7 @@ static void rcu_free_pool(struct rcu_head *rcu) { struct worker_pool *pool = container_of(rcu, struct worker_pool, rcu); - idr_destroy(&pool->worker_idr); + ida_destroy(&pool->worker_ida); free_workqueue_attrs(pool->attrs); kfree(pool); } -- cgit v1.2.3