[PATCH 6/7 V6] workqueue: new day don't need WORKER_REBIND for busy rebinding

From: Lai Jiangshan
Date: Sat Sep 08 2012 - 13:12:11 EST


because old busy_worker_rebind_fn() have to wait until all idle worker finish.
so we have to use two flags WORKER_UNBOUND and WORKER_REBIND to avoid
prematurely clear all NOT_RUNNING bit when highly frequent offline/online.

but current code don't need to wait idle workers. so we don't need to
use two flags, just one is enough. remove WORKER_REBIND from busy rebinding.

Signed-off-by: Lai Jiangshan <laijs@xxxxxxxxxxxxxx>
---
kernel/workqueue.c | 9 +--------
1 files changed, 1 insertions(+), 8 deletions(-)

diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index d9765c4..4863162 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -1639,7 +1639,7 @@ static void busy_worker_rebind_fn(struct work_struct *work)
struct global_cwq *gcwq = worker->pool->gcwq;

if (worker_maybe_bind_and_lock(worker))
- worker_clr_flags(worker, WORKER_REBIND);
+ worker_clr_flags(worker, WORKER_UNBOUND);

spin_unlock_irq(&gcwq->lock);
}
@@ -1692,13 +1692,6 @@ static void rebind_workers(struct global_cwq *gcwq)
for_each_busy_worker(worker, i, pos, gcwq) {
struct work_struct *rebind_work = &worker->rebind_work;
struct workqueue_struct *wq;
- unsigned long worker_flags = worker->flags;
-
- /* morph UNBOUND to REBIND */
- worker_flags &= ~WORKER_UNBOUND;
- worker_flags |= WORKER_REBIND;
- /* ensure the wq_worker_sleeping() see the right flags */
- ACCESS_ONCE(worker->flags) = worker_flags;

if (test_and_set_bit(WORK_STRUCT_PENDING_BIT,
work_data_bits(rebind_work)))
--
1.7.4.4

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