[PATCH 2/6] workqueue: new day don't need WORKER_REBIND for busy rebinding

From: Lai Jiangshan
Date: Sat Sep 15 2012 - 04:47:22 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 nor release gcwq->lock
when it is doing rebind in rebind_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 | 8 +-------
1 files changed, 1 insertions(+), 7 deletions(-)

diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index e8b28d6..4b1ff46 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -1641,7 +1641,7 @@ 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);

@@ -1696,15 +1696,9 @@ static void rebind_workers(struct global_cwq *gcwq)

/* rebind busy workers */
for_each_busy_worker(worker, i, pos, gcwq) {
- unsigned long worker_flags = worker->flags;
struct work_struct *rebind_work = &worker->rebind_work;
struct workqueue_struct *wq;

- /* morph UNBOUND to REBIND atomically */
- worker_flags &= ~WORKER_UNBOUND;
- worker_flags |= WORKER_REBIND;
- ACCESS_ONCE(worker->flags) = worker_flags;
if (test_and_set_bit(WORK_STRUCT_PENDING_BIT,

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/