multipath: Set 'tur' as the default path checker for NetApp LUNs

In our tests, we've noticed that the 'tur' checker provides
better performance compared to 'directio' primarily because 'tur'
does not use FS-based requests unlike 'directio'. Moreover with
Hannes' recent async tur enhancement, the 'tur' checker is more
efficient now than before.

So we'd prefer using 'tur' as the default path checker for NetApp
LUNs now. The below patch enables the same by updating the
.checker_name in the hwtable for NetApp LUNs.

Signed-off-by: Martin George <marting@netapp.com>

diff --git a/libmultipath/hwtable.c b/libmultipath/hwtable.c
index 020c8aa994bf338d5ca130de6db4cfea6f4f62d0..b8a62dd2095d7b19c8ed74853760afb959d11d1d 100644 (file)
--- a/libmultipath/hwtable.c
+++ b/libmultipath/hwtable.c
@@ -955,7 +955,7 @@ static struct hwentry default_hw[] = {
                .rr_weight     = RR_WEIGHT_NONE,
                .no_path_retry = NO_PATH_RETRY_UNDEF,
                .minio         = 128,
-               .checker_name  = DIRECTIO,
+               .checker_name  = TUR,
                .prio_name     = PRIO_ONTAP,
                .prio_args     = NULL,
        },