worker_set_flags() doesn't necessarily wake next worker and the @wakeup
can be removed, the caller can use the following conbination instead
when needed:
worker_set_flags();
if (need_more_worker(pool))
wake_up_worker(pool);
It reduces the machine-code and footprint for the process_one_work()
if worker_set_flags() is really inlined.
Signed-off-by: Lai Jiangshan <la...@cn.fujitsu.com>
---
kernel/workqueue.c | 27 ++++++++-------------------
1 files changed, 8 insertions(+), 19 deletions(-)
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index cd75689..40b1f00 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -867,35 +867,22 @@ struct task_struct *wq_worker_sleeping(struct task_struct
*task, int cpu)
* worker_set_flags - set worker flags and adjust nr_running accordingly
* @worker: self
* @flags: flags to set
- * @wakeup: wakeup an idle worker if necessary
*
- * Set @flags in @worker->flags and adjust nr_running accordingly. If
- * nr_running becomes zero and @wakeup is %true, an idle worker is
- * woken up.
+ * Set @flags in @worker->flags and adjust nr_running accordingly.
*
* CONTEXT:
* spin_lock_irq(pool->lock)
*/
-static inline void worker_set_flags(struct worker *worker, unsigned int flags,
- bool wakeup)
+static inline void worker_set_flags(struct worker *worker, unsigned int flags)
{
struct worker_pool *pool = worker->pool;
WARN_ON_ONCE(worker->task != current);
- /*
- * If transitioning into NOT_RUNNING, adjust nr_running and
- * wake up an idle worker as necessary if requested by
- * @wakeup.
- */
+ /* If transitioning into NOT_RUNNING, adjust nr_running. */
if ((flags & WORKER_NOT_RUNNING) &&
!(worker->flags & WORKER_NOT_RUNNING)) {
- if (wakeup) {
- if (atomic_dec_and_test(&pool->nr_running) &&
- !list_empty(&pool->worklist))
- wake_up_worker(pool);
- } else
- atomic_dec(&pool->nr_running);
+ atomic_dec(&pool->nr_running);
}
worker->flags |= flags;
@@ -2043,9 +2030,11 @@ __acquires(&pool->lock)
/*
* CPU intensive works don't participate in concurrency
* management. They're the scheduler's responsibility.
+ * Another worker should be woken up after WORKER_CPU_INTENSIVE
+ * is set, see next code.
*/
if (unlikely(cpu_intensive))
- worker_set_flags(worker, WORKER_CPU_INTENSIVE, true);
+ worker_set_flags(worker, WORKER_CPU_INTENSIVE);
/*
* Wake up another worker if necessary. It is a no-op
@@ -2210,7 +2199,7 @@ recheck:
}
} while (keep_working(pool));
- worker_set_flags(worker, WORKER_PREP, false);
+ worker_set_flags(worker, WORKER_PREP);
sleep:
/*
* pool->lock is held and there's no work to process and no need to
--
1.7.4.4
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