From 29b1cb416a2920fbc70041e4382920ae2d86f426 Mon Sep 17 00:00:00 2001
From: Lai Jiangshan <laijs@cn.fujitsu.com>
Date: Tue, 22 Jul 2014 13:04:27 +0800
Subject: [PATCH] workqueue: remove the stale comment in
pwq_unbound_release_workfn()
In 75ccf5950f82 ("workqueue: prepare flush_workqueue() for dynamic
creation and destrucion of unbound pool_workqueues"), a comment
about the synchronization for the pwq in pwq_unbound_release_workfn()
was added. The comment claimed the flush_mutex wasn't strictly
necessary, it was correct in that time, due to the pwq was protected
by workqueue_lock.
But it is incorrect now since the wq->flush_mutex was renamed to
wq->mutex and workqueue_lock was removed, the wq->mutex is strictly
needed. But the comment was miss-updated when the synchronization
was changed.
This patch removes the incorrect comments and doesn't add any new
comment to explain why wq->mutex is needed here, which is definitely
obvious and wq->pwqs_node has "WQ" notation in its definition which is
better comment.
The old commit mentioned above also introduced a comment in link_pwq()
about the synchronization. This comment is also removed in this patch
since the whole link_pwq() is proteced by wq->mutex.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
---
kernel/workqueue.c | 10 +---------
1 file changed, 1 insertion(+), 9 deletions(-)
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 4d9600faa4008..0732d33d6dd5c 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -3530,11 +3530,6 @@ static void pwq_unbound_release_workfn(struct work_struct *work)
if (WARN_ON_ONCE(!(wq->flags & WQ_UNBOUND)))
return;
- /*
- * Unlink @pwq. Synchronization against wq->mutex isn't strictly
- * necessary on release but do it anyway. It's easier to verify
- * and consistent with the linking path.
- */
mutex_lock(&wq->mutex);
list_del_rcu(&pwq->pwqs_node);
is_last = list_empty(&wq->pwqs);
@@ -3631,10 +3626,7 @@ static void link_pwq(struct pool_workqueue *pwq)
if (!list_empty(&pwq->pwqs_node))
return;
- /*
- * Set the matching work_color. This is synchronized with
- * wq->mutex to avoid confusing flush_workqueue().
- */
+ /* set the matching work_color */
pwq->work_color = wq->work_color;
/* sync max_active to the current setting */
--
2.30.2