[ofa-general] [PATCH 6/6] opensm/Unicast Routing Cache: manpage entry

[Yevgeny Kliteynik]

Signed-off-by: Yevgeny Kliteynik <kliteyn at dev.mellanox.co.il>
---
 opensm/man/opensm.8.in |   14 +++++++++++++-
 1 files changed, 13 insertions(+), 1 deletions(-)

diff --git a/opensm/man/opensm.8.in b/opensm/man/opensm.8.in
index c1ea584..efadf8e 100644
--- a/opensm/man/opensm.8.in
+++ b/opensm/man/opensm.8.in
@@ -10,7 +10,7 @@ opensm \- InfiniBand subnet manager and administration (SM/SA)
 [\-g(uid) <GUID in hex>] [\-l(mc) <LMC>]
 [\-p(riority) <PRIORITY>] [\-smkey <SM_Key>] [\-r(eassign_lids)]
 [\-R <engine name(s)> | \-\-routing_engine <engine name(s)>]
-[\-z | \-\-connect_roots]
+[\-A | \-\-ucast_cache] [\-z | \-\-connect_roots]
 [\-M <file name> | \-\-lid_matrix_file <file name>]
 [\-U <file name> | \-\-lfts_file <file name>]
 [\-S | \-\-sadb_file <file name>] [\-a | \-\-root_guid_file <path to file>]
@@ -122,6 +122,18 @@ separated by commas so that specific ordering of routing algorithms
 will be tried if earlier routing engines fail.
 Supported engines: minhop, updn, file, ftree, lash, dor
 .TP
+\fB\-A\fR, \fB\-\-ucast_cache\fR
+This option enables unicast routing cache and prevents routing
+recalculation (which is a heavy task in a large cluster) when
+there was no topology change detected during the heavy sweep, or
+when the topology change does not require new routing calculation,
+e.g. when one or more CAs/RTRs/leaf switches going down, or one or
+more of these nodes coming back after being down.
+A very common case that is handled by the unicast routing cache
+is host reboot, which otherwise would cause two full routing
+recalculations: one when the host goes down, and the other when
+the host comes back online.
+.TP
 \fB\-z\fR, \fB\-\-connect_roots\fR
 This option enforces a routing engine (currently up/down
 only) to make connectivity between root switches and in
-- 
1.5.1.4