Messages in this thread Patch in this message | | | From | Philipp Reisner <> | Subject | [PATCH 17/18] drbd: try hard to max out the updates per AL transaction | Date | Tue, 19 Mar 2013 18:16:58 +0100 |
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From: Lars Ellenberg <lars.ellenberg@linbit.com>
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> --- 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
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