diff options
| author | Lars Ellenberg <lars.ellenberg@linbit.com> | 2014-09-11 14:29:12 +0200 |
|---|---|---|
| committer | Jens Axboe <axboe@fb.com> | 2014-09-11 08:41:29 -0600 |
| commit | 729e8b87bac63dee09302ddffc05a7ba0e50c9ad (patch) | |
| tree | f5e211f46358cec78fe411b1ddbba5f8f307991f /drivers/block | |
| parent | abde9cc6a59cb7f07fda4c77fee2150314e423fa (diff) | |
| download | blackbird-op-linux-729e8b87bac63dee09302ddffc05a7ba0e50c9ad.tar.gz blackbird-op-linux-729e8b87bac63dee09302ddffc05a7ba0e50c9ad.zip | |
drbd: reduce lock contention in drbd_worker
The worker may now dequeue work items in batches.
This should reduce lock contention during busy periods.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'drivers/block')
| -rw-r--r-- | drivers/block/drbd/drbd_worker.c | 10 |
1 files changed, 4 insertions, 6 deletions
diff --git a/drivers/block/drbd/drbd_worker.c b/drivers/block/drbd/drbd_worker.c index 3ed2d871272e..d2d1f97511bd 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(); |
