diff options
| -rw-r--r-- | drivers/block/drbd/drbd_req.c | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/drivers/block/drbd/drbd_req.c b/drivers/block/drbd/drbd_req.c index d72f2fef1cba..9f7ff1cb46ff 100644 --- a/drivers/block/drbd/drbd_req.c +++ b/drivers/block/drbd/drbd_req.c @@ -1226,6 +1226,37 @@ void do_submit(struct work_struct *ws) break; wait_event(mdev->al_wait, prepare_al_transaction_nonblock(mdev, &incoming, &pending)); + /* Maybe more was queued, while we prepared the transaction? + * Try to stuff them into this transaction as well. + * Be strictly non-blocking here, no wait_event, we already + * have something to commit. + * Stop if we don't make any more progres. + */ + for (;;) { + LIST_HEAD(more_pending); + LIST_HEAD(more_incoming); + bool made_progress; + + /* It is ok to look outside the lock, + * it's only an optimization anyways */ + if (list_empty(&mdev->submit.writes)) + break; + + spin_lock(&mdev->submit.lock); + list_splice_tail_init(&mdev->submit.writes, &more_incoming); + spin_unlock(&mdev->submit.lock); + + if (list_empty(&more_incoming)) + break; + + made_progress = prepare_al_transaction_nonblock(mdev, &more_incoming, &more_pending); + + list_splice_tail_init(&more_pending, &pending); + list_splice_tail_init(&more_incoming, &incoming); + + if (!made_progress) + break; + } drbd_al_begin_io_commit(mdev, false); list_for_each_entry_safe(req, tmp, &pending, tl_requests) { |