summaryrefslogtreecommitdiff
path: root/drivers/block/drbd
diff options
context:
space:
mode:
authorLars Ellenberg <lars.ellenberg@linbit.com>2013-03-19 17:16:58 (GMT)
committerJens Axboe <axboe@kernel.dk>2013-03-23 04:18:09 (GMT)
commit45ad07b3ac1e3062188fb760fe71cafb4a100215 (patch)
tree3911830e2d53a830007f6d70fdac39d00d065bb2 /drivers/block/drbd
parent7e8c288f6cde950a6ca001ec06a32c8c2cf4180e (diff)
downloadlinux-fsl-qoriq-45ad07b3ac1e3062188fb760fe71cafb4a100215.tar.xz
drbd: try hard to max out the updates per AL transaction
There may have been more incoming requests while we where preparing the current transaction. Try to consolidate more updates into this transaction until we make no more progres. Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'drivers/block/drbd')
-rw-r--r--drivers/block/drbd/drbd_req.c31
1 files changed, 31 insertions, 0 deletions
diff --git a/drivers/block/drbd/drbd_req.c b/drivers/block/drbd/drbd_req.c
index d72f2fe..9f7ff1c 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) {