[PATCH 13/40] workqueue: separate out process_one_work()

Tejun Heo
2010-01-18T01:01:36Z

Separate out process_one_work() out of run_workqueue(). This patch
doesn't cause any behavior change.

Signed-off-by: Tejun Heo <tj@kernel.org>
---
kernel/workqueue.c | 100 +++++++++++++++++++++++++++++++--------------------
1 files changed, 61 insertions(+), 39 deletions(-)

diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index f8e4d67..aa1d680 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -395,51 +395,73 @@ int queue_delayed_work_on(int cpu, struct workqueue_struct *wq,
}
EXPORT_SYMBOL_GPL(queue_delayed_work_on);

+/**
+ * process_one_work - process single work
+ * @cwq: cwq to process work for
+ * @work: work to process
+ *
+ * Process @work. This function contains all the logics necessary to
+ * process a single work including synchronization against and
+ * interaction with other workers on the same cpu, queueing and
+ * flushing. As long as context requirement is met, any worker can
+ * call this function to process a work.
+ *
+ * CONTEXT:
+ * spin_lock_irq(cwq->lock) which is released and regrabbed.
+ */
+static void process_one_work(struct cpu_workqueue_struct *cwq,
+ struct work_struct *work)
+{
+ work_func_t f = work->func;
+#ifdef CONFIG_LOCKDEP
+ /*
+ * It is permissible to free the struct work_struct from
+ * inside the function that is called from it, this we need to
+ * take into account for lockdep too. To avoid bogus "held
+ * lock freed" warnings as well as problems when looking into
+ * work->lockdep_map, make a copy and use that here.
+ */
+ struct lockdep_map lockdep_map = work->lockdep_map;
+#endif
+ /* claim and process */
+ trace_workqueue_execution(cwq->thread, work);
+ debug_work_deactivate(work);
+ cwq->current_work = work;
+ list_del_init(&work->entry);
+
+ spin_unlock_irq(&cwq->lock);
+
+ BUG_ON(get_wq_data(work) != cwq);
+ work_clear_pending(work);
+ lock_map_acquire(&cwq->wq->lockdep_map);
+ lock_map_acquire(&lockdep_map);
+ f(work);
+ lock_map_release(&lockdep_map);
+ lock_map_release(&cwq->wq->lockdep_map);
+
+ if (unlikely(in_atomic() || lockdep_depth(current) > 0)) {
+ printk(KERN_ERR "BUG: workqueue leaked lock or atomic: "
+ "%s/0x%08x/%d\n",
+ current->comm, preempt_count(), task_pid_nr(current));
+ printk(KERN_ERR " last function: ");
+ print_symbol("%s\n", (unsigned long)f);
+ debug_show_held_locks(current);
+ dump_stack();
+ }
+
+ spin_lock_irq(&cwq->lock);
+
+ /* we're done with it, release */
+ cwq->current_work = NULL;
+}
+
static void run_workqueue(struct cpu_workqueue_struct *cwq)
{
spin_lock_irq(&cwq->lock);
while (!list_empty(&cwq->worklist)) {
struct work_struct *work = list_entry(cwq->worklist.next,
struct work_struct, entry);
- work_func_t f = work->func;
-#ifdef CONFIG_LOCKDEP
- /*
- * It is permissible to free the struct work_struct
- * from inside the function that is called from it,
- * this we need to take into account for lockdep too.
- * To avoid bogus "held lock freed" warnings as well
- * as problems when looking into work->lockdep_map,
- * make a copy and use that here.
- */
- struct lockdep_map lockdep_map = work->lockdep_map;
-#endif
- trace_workqueue_execution(cwq->thread, work);
- debug_work_deactivate(work);
- cwq->current_work = work;
- list_del_init(cwq->worklist.next);
- spin_unlock_irq(&cwq->lock);
-
- BUG_ON(get_wq_data(work) != cwq);
- work_clear_pending(work);
- lock_map_acquire(&cwq->wq->lockdep_map);
- lock_map_acquire(&lockdep_map);
- f(work);
- lock_map_release(&lockdep_map);
- lock_map_release(&cwq->wq->lockdep_map);
-
- if (unlikely(in_atomic() || lockdep_depth(current) > 0)) {
- printk(KERN_ERR "BUG: workqueue leaked lock or atomic: "
- "%s/0x%08x/%d\n",
- current->comm, preempt_count(),
- task_pid_nr(current));
- printk(KERN_ERR " last function: ");
- print_symbol("%s\n", (unsigned long)f);
- debug_show_held_locks(current);
- dump_stack();
- }
-
- spin_lock_irq(&cwq->lock);
- cwq->current_work = NULL;
+ process_one_work(cwq, work);
}
spin_unlock_irq(&cwq->lock);
}
--
1.6.4.2