diff options
author | Tejun Heo <tj@kernel.org> | 2013-02-14 03:29:10 (GMT) |
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committer | Tejun Heo <tj@kernel.org> | 2013-02-14 03:29:10 (GMT) |
commit | 8d03ecfe471802d6afe97da97722b6924533aa82 (patch) | |
tree | 1178cacfdd36358665f9a4c6325329346b221dd0 /kernel | |
parent | 1dd638149f1f9d7d7dbb32591d5c7c2a0ea36264 (diff) | |
download | linux-fsl-qoriq-8d03ecfe471802d6afe97da97722b6924533aa82.tar.xz |
workqueue: reimplement is_chained_work() using current_wq_worker()
is_chained_work() was added before current_wq_worker() and implemented
its own ham-fisted way of finding out whether %current is a workqueue
worker - it iterates through all possible workers.
Drop the custom implementation and reimplement using
current_wq_worker().
Signed-off-by: Tejun Heo <tj@kernel.org>
Diffstat (limited to 'kernel')
-rw-r--r-- | kernel/workqueue.c | 33 |
1 files changed, 8 insertions, 25 deletions
diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 0d26ab3..ea7f696 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -1159,35 +1159,18 @@ static void insert_work(struct cpu_workqueue_struct *cwq, /* * Test whether @work is being queued from another work executing on the - * same workqueue. This is rather expensive and should only be used from - * cold paths. + * same workqueue. */ static bool is_chained_work(struct workqueue_struct *wq) { - unsigned long flags; - unsigned int cpu; - - for_each_cwq_cpu(cpu, wq) { - struct cpu_workqueue_struct *cwq = get_cwq(cpu, wq); - struct worker_pool *pool = cwq->pool; - struct worker *worker; - struct hlist_node *pos; - int i; + struct worker *worker; - spin_lock_irqsave(&pool->lock, flags); - for_each_busy_worker(worker, i, pos, pool) { - if (worker->task != current) - continue; - spin_unlock_irqrestore(&pool->lock, flags); - /* - * I'm @worker, no locking necessary. See if @work - * is headed to the same workqueue. - */ - return worker->current_cwq->wq == wq; - } - spin_unlock_irqrestore(&pool->lock, flags); - } - return false; + worker = current_wq_worker(); + /* + * Return %true iff I'm a worker execuing a work item on @wq. If + * I'm @worker, it's safe to dereference it without locking. + */ + return worker && worker->current_cwq->wq == wq; } static void __queue_work(unsigned int cpu, struct workqueue_struct *wq, |