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authorPhilipp Reisner <philipp.reisner@linbit.com>2011-11-11 12:31:20 +0100
committerPhilipp Reisner <philipp.reisner@linbit.com>2012-11-08 16:58:10 +0100
commit380207d08e7c4d1b19c0323777278992b4fbf9d6 (patch)
tree3a35f3543810eb2a7d87f15dd62a8fe8e13aad76 /include
parentd10b4ea32bf2b77a3d56a20992cd549978df7b38 (diff)
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>
Diffstat (limited to 'include')
-rw-r--r--include/linux/drbd.h8
-rw-r--r--include/linux/drbd_genl.h1
-rw-r--r--include/linux/drbd_limits.h1
3 files changed, 10 insertions, 0 deletions
diff --git a/include/linux/drbd.h b/include/linux/drbd.h
index 1e9f754b66ac..157ba3d74dc7 100644
--- a/include/linux/drbd.h
+++ b/include/linux/drbd.h
@@ -102,6 +102,14 @@ enum drbd_on_congestion {
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,
diff --git a/include/linux/drbd_genl.h b/include/linux/drbd_genl.h
index 2e6cefefe5e5..826008f297fe 100644
--- a/include/linux/drbd_genl.h
+++ b/include/linux/drbd_genl.h
@@ -129,6 +129,7 @@ GENL_struct(DRBD_NLA_DISK_CONF, 3, disk_conf,
__flg_field_def(18, DRBD_GENLA_F_MANDATORY, disk_drain, DRBD_DISK_DRAIN_DEF)
__flg_field_def(19, DRBD_GENLA_F_MANDATORY, md_flushes, DRBD_MD_FLUSHES_DEF)
__u32_field_def(20, DRBD_GENLA_F_MANDATORY, disk_timeout, DRBD_DISK_TIMEOUT_DEF)
+ __u32_field_def(21, 0 /* OPTIONAL */, read_balancing, DRBD_READ_BALANCING_DEF)
)
GENL_struct(DRBD_NLA_RESOURCE_OPTS, 4, res_opts,
diff --git a/include/linux/drbd_limits.h b/include/linux/drbd_limits.h
index 6d0a24331ed2..17ef66a5c114 100644
--- a/include/linux/drbd_limits.h
+++ b/include/linux/drbd_limits.h
@@ -161,6 +161,7 @@
#define DRBD_RR_CONFLICT_DEF ASB_DISCONNECT
#define DRBD_ON_NO_DATA_DEF OND_IO_ERROR
#define DRBD_ON_CONGESTION_DEF OC_BLOCK
+#define DRBD_READ_BALANCING_DEF RB_PREFER_LOCAL
#define DRBD_MAX_BIO_BVECS_MIN 0
#define DRBD_MAX_BIO_BVECS_MAX 128