drbd: Load balancing of read requests
New config option for the disk secition "read-balancing", with
the values: prefer-local, prefer-remote, round-robin, when-congested-remote.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
diff --git a/include/linux/drbd.h b/include/linux/drbd.h
index 1e9f754..157ba3d 100644
--- a/include/linux/drbd.h
+++ b/include/linux/drbd.h
@@ -102,6 +102,14 @@
OC_DISCONNECT,
};
+enum drbd_read_balancing {
+ RB_PREFER_LOCAL,
+ RB_PREFER_REMOTE,
+ RB_ROUND_ROBIN,
+ RB_LEAST_PENDING,
+ RB_CONGESTED_REMOTE,
+};
+
/* KEEP the order, do not delete or insert. Only append. */
enum drbd_ret_code {
ERR_CODE_BASE = 100,