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authorKiyoshi Ueda <k-ueda@ct.jp.nec.com>2009-06-22 10:12:28 +0100
committerAlasdair G Kergon <agk@redhat.com>2009-06-22 10:12:28 +0100
commitf392ba889b019602976082bfe7bf486c2594f85c (patch)
tree962e8f354dfe3df2021476412be8d1bcec8a03d0 /drivers/md/Kconfig
parentfd5e033908b7b743b5650790f196761dd930f988 (diff)
downloadlinux-f392ba889b019602976082bfe7bf486c2594f85c.tar.gz
dm mpath: add service time load balancer
This patch adds a service time oriented dynamic load balancer,
dm-service-time, which selects the path with the shortest estimated
service time for the incoming I/O.
The service time is estimated by dividing the in-flight I/O size
by a performance value of each path.

The performance value can be given as a table argument at the table
loading time.  If no performance value is given, all paths are
considered equal.

Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Diffstat (limited to 'drivers/md/Kconfig')
-rw-r--r--drivers/md/Kconfig10
1 files changed, 10 insertions, 0 deletions
diff --git a/drivers/md/Kconfig b/drivers/md/Kconfig
index 3b311d273346..09f93fa68912 100644
--- a/drivers/md/Kconfig
+++ b/drivers/md/Kconfig
@@ -258,6 +258,16 @@ config DM_MULTIPATH_QL
 
 	  If unsure, say N.
 
+config DM_MULTIPATH_ST
+	tristate "I/O Path Selector based on the service time"
+	depends on DM_MULTIPATH
+	---help---
+	  This path selector is a dynamic load balancer which selects
+	  the path expected to complete the incoming I/O in the shortest
+	  time.
+
+	  If unsure, say N.
+
 config DM_DELAY
 	tristate "I/O delaying target (EXPERIMENTAL)"
 	depends on BLK_DEV_DM && EXPERIMENTAL