[dm-devel] [PATCH] [RFC] multipath: change the DEFAULT_MINIO for the request based multipath

[Malahal Naineni]

The value of 1000 is good for bio based multipath. Seen 50% increase in
I/O ops by setting it to 1 in request based multipath configuration.
This patch would give poor performance for people still using the bio
based multipath!

Is it possible to detect request based multipath and change only for
those configurations?

diff -r e504a50b0db5 -r 91d6dae7d882 libmultipath/defaults.h
--- a/libmultipath/defaults.h	Wed Jan 19 13:16:40 2011 -0800
+++ b/libmultipath/defaults.h	Wed Jan 19 13:29:52 2011 -0800
@@ -5,7 +5,7 @@
 #define DEFAULT_ALIAS_PREFIX	"mpath"
 #define DEFAULT_FEATURES	"0"
 #define DEFAULT_HWHANDLER	"0"
-#define DEFAULT_MINIO		1000
+#define DEFAULT_MINIO		1
 #define DEFAULT_PGPOLICY       FAILOVER
 #define DEFAULT_FAILBACK       -FAILBACK_MANUAL
 #define DEFAULT_RR_WEIGHT      RR_WEIGHT_NONE