linux-kernel - [PATCH 1/8] workqueue: remove @cpu from wq_worker

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Date:	Mon, 15 Apr 2013 00:41:49 +0800
From:	Lai Jiangshan <laijs@...fujitsu.com>
To:	Tejun Heo <tj@...nel.org>, linux-kernel@...r.kernel.org
Cc:	Lai Jiangshan <laijs@...fujitsu.com>,
	Ingo Molnar <mingo@...hat.com>,
	Peter Zijlstra <peterz@...radead.org>
Subject: [PATCH 1/8] workqueue: remove @cpu from wq_worker_sleeping()

WARN_ON_ONCE(cpu != raw_smp_processor_id()) in
wq_worker_sleeping() in useless, the caller ensures
cpu == raw_smp_processor_id().

We should use WARN_ON_ONCE(pool->cpu != raw_smp_processor_id())
to do the expected test.

It results @cpu removed from wq_worker_sleeping()

Signed-off-by: Lai Jiangshan <laijs@...fujitsu.com>
---
 kernel/sched/core.c         |    2 +-
 kernel/workqueue.c          |    7 +++----
 kernel/workqueue_internal.h |    2 +-
 3 files changed, 5 insertions(+), 6 deletions(-)

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 23606ee..ffc06ad 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -2907,7 +2907,7 @@ need_resched:
 			if (prev->flags & PF_WQ_WORKER) {
 				struct task_struct *to_wakeup;
 
-				to_wakeup = wq_worker_sleeping(prev, cpu);
+				to_wakeup = wq_worker_sleeping(prev);
 				if (to_wakeup)
 					try_to_wake_up_local(to_wakeup);
 			}
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index c273376..b3095ad 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -807,7 +807,6 @@ void wq_worker_waking_up(struct task_struct *task, int cpu)
 /**
  * wq_worker_sleeping - a worker is going to sleep
  * @task: task going to sleep
- * @cpu: CPU in question, must be the current CPU number
  *
  * This function is called during schedule() when a busy worker is
  * going to sleep.  Worker on the same cpu can be woken up by
@@ -817,9 +816,9 @@ void wq_worker_waking_up(struct task_struct *task, int cpu)
  * spin_lock_irq(rq->lock)
  *
  * RETURNS:
- * Worker task on @cpu to wake up, %NULL if none.
+ * Worker task on the same pool to wake up, %NULL if none.
  */
-struct task_struct *wq_worker_sleeping(struct task_struct *task, int cpu)
+struct task_struct *wq_worker_sleeping(struct task_struct *task)
 {
 	struct worker *worker = kthread_data(task), *to_wakeup = NULL;
 	struct worker_pool *pool;
@@ -835,7 +834,7 @@ struct task_struct *wq_worker_sleeping(struct task_struct *task, int cpu)
 	pool = worker->pool;
 
 	/* this can only happen on the local cpu */
-	if (WARN_ON_ONCE(cpu != raw_smp_processor_id()))
+	if (WARN_ON_ONCE(pool->cpu != raw_smp_processor_id()))
 		return NULL;
 
 	/*
diff --git a/kernel/workqueue_internal.h b/kernel/workqueue_internal.h
index 84ab6e1..aec8df4 100644
--- a/kernel/workqueue_internal.h
+++ b/kernel/workqueue_internal.h
@@ -57,6 +57,6 @@ static inline struct worker *current_wq_worker(void)
  * sched.c and workqueue.c.
  */
 void wq_worker_waking_up(struct task_struct *task, int cpu);
-struct task_struct *wq_worker_sleeping(struct task_struct *task, int cpu);
+struct task_struct *wq_worker_sleeping(struct task_struct *task);
 
 #endif /* _KERNEL_WORKQUEUE_INTERNAL_H */
-- 
1.7.7.6

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