From: Lars Ellenberg <lars.ellenb...@linbit.com>
The worker may now dequeue work items in batches.
This should reduce lock contention during busy periods.
Signed-off-by: Philipp Reisner <philipp.reis...@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenb...@linbit.com>
---
drivers/block/drbd/drbd_worker.c | 10 ++++------
1 file changed, 4 insertions(+), 6 deletions(-)
diff --git a/drivers/block/drbd/drbd_worker.c b/drivers/block/drbd/drbd_worker.c
index 3ed2d87..d2d1f97 100644
--- a/drivers/block/drbd/drbd_worker.c
+++ b/drivers/block/drbd/drbd_worker.c
@@ -2026,8 +2026,6 @@ static void wait_for_work(struct drbd_connection
*connection, struct list_head *
prepare_to_wait(&connection->sender_work.q_wait, &wait,
TASK_INTERRUPTIBLE);
spin_lock_irq(&connection->resource->req_lock);
spin_lock(&connection->sender_work.q_lock); /* FIXME get
rid of this one? */
- /* dequeue single item only,
- * we still use drbd_queue_work_front() in some places */
if (!list_empty(&connection->sender_work.q))
list_splice_tail_init(&connection->sender_work.q,
work_list);
spin_unlock(&connection->sender_work.q_lock); /* FIXME get
rid of this one? */
@@ -2114,7 +2112,7 @@ int drbd_worker(struct drbd_thread *thi)
if (get_t_state(thi) != RUNNING)
break;
- while (!list_empty(&work_list)) {
+ if (!list_empty(&work_list)) {
w = list_first_entry(&work_list, struct drbd_work,
list);
list_del_init(&w->list);
update_worker_timing_details(connection, w->cb);
@@ -2130,13 +2128,13 @@ int drbd_worker(struct drbd_thread *thi)
update_worker_timing_details(connection,
do_unqueued_work);
do_unqueued_work(connection);
}
- while (!list_empty(&work_list)) {
+ if (!list_empty(&work_list)) {
w = list_first_entry(&work_list, struct drbd_work,
list);
list_del_init(&w->list);
update_worker_timing_details(connection, w->cb);
w->cb(w, 1);
- }
- dequeue_work_batch(&connection->sender_work, &work_list);
+ } else
+ dequeue_work_batch(&connection->sender_work,
&work_list);
} while (!list_empty(&work_list) || test_bit(DEVICE_WORK_PENDING,
&connection->flags));
rcu_read_lock();
--
1.9.1
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
