From: Lars Ellenberg <lars.ellenberg@linbit.com>
Date: Tue, 19 Mar 2013 17:16:49 +0000 (+0100)
Subject: drbd: drbd_al_being_io: short circuit to reduce latency
X-Git-Tag: omap-for-v3.10/fixes-for-merge-window-part2~10^2~47
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=ebfd5d8f715167b886c9401e6b123847187f137b;p=pandora-kernel.git

drbd: drbd_al_being_io: short circuit to reduce latency

A request hitting an already "hot" extent should proceed right away,
even if some other requests need to wait for pending transactions.

Without that short-circuit, several simultaneous make_request contexts
race for committing the transaction, possibly penalizing the innocent.

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>
---

Reading git-diff-tree failed