From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Philipp Reisner To: linux-kernel@vger.kernel.org Date: Tue, 19 Mar 2013 18:16:58 +0100 Message-Id: <1363713419-17803-18-git-send-email-philipp.reisner@linbit.com> In-Reply-To: <1363713419-17803-1-git-send-email-philipp.reisner@linbit.com> References: <1363713419-17803-1-git-send-email-philipp.reisner@linbit.com> Cc: Jens Axboe , lars.ellenberg@linbit.com, drbd-dev@lists.linbit.com Subject: [Drbd-dev] [PATCH 17/18] drbd: try hard to max out the updates per AL transaction List-Id: "*Coordination* of development, patches, contributions -- *Questions* \(even to developers\) go to drbd-user, please." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , From: Lars Ellenberg 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 Signed-off-by: Lars Ellenberg --- drivers/block/drbd/drbd_req.c | 31 +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+) 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) { -- 1.7.9.5