In this code:
if ((worker->flags & WORKER_UNBOUND) && need_more_worker(pool))
wake_up_worker(pool);
the first test is unneeded. Even the first test is removed, it doesn't affect
the wake-up logic when WORKER_UNBOUND. And it will not introduce any useless
wake-up when !WORKER_UNBOUND since the nr_running >= 1 except only one case.
It will introduce useless/redundant wake-up when cpu_intensive, but this
case is rare and next patch will also remove this redundant wake-up.
Signed-off-by: Lai Jiangshan <la...@cn.fujitsu.com>
---
kernel/workqueue.c | 9 ++++++---
1 files changed, 6 insertions(+), 3 deletions(-)
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index a791a8c..cd75689 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. It is a no-op
+ * when the current worker is concurrency managed since
+ * pool->nr_running >= 1. But it is required for non-concurrency
+ * managed workers, mainly for unbound pool which requries
+ * chain execution of currently pending work items ASAP.
*/
- if ((worker->flags & WORKER_UNBOUND) && need_more_worker(pool))
+ if (need_more_worker(pool))
wake_up_worker(pool);
/*
--
1.7.4.4
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