workqueue: remove an unneeded UNBOUND test before waking up the next worker

In process_one_work():

	if ((worker->flags & WORKER_UNBOUND) && need_more_worker(pool))
		wake_up_worker(pool);

the first test is unneeded.  Even if the first test is removed, it
doesn't affect the wake-up logic for WORKER_UNBOUND, and it will not
introduce any useless wake-ups for normal per-cpu workers since
nr_running is always >= 1.  It will introduce useless/redundant
wake-ups for CPU_INTENSIVE, but this case is rare and the next patch
will also remove this redundant wake-up.

tj: Minor updates to the description and comment.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

1 files changed, 6 insertions, 3 deletions

diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index d3444169e261..c20cfbe89194 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -2048,10 +2048,13 @@ __acquires(&pool->lock)
                 worker_set_flags(worker, WORKER_CPU_INTENSIVE, true);
 
         /*
-         * Unbound pool isn't concurrency managed and work items should be
-         * executed ASAP.  Wake up another worker if necessary.
+         * Wake up another worker if necessary.  The condition is always
+         * false for normal per-cpu workers since nr_running would always
+         * be >= 1 at this point.  This is used to chain execution of the
+         * pending work items for WORKER_NOT_RUNNING workers such as the
+         * UNBOUND ones.
          */
-        if ((worker->flags & WORKER_UNBOUND) && need_more_worker(pool))
+        if (need_more_worker(pool))
                 wake_up_worker(pool);
 
         /*