X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=planetlab%2Fexp-tool%2FMakefile.help;fp=planetlab%2Fexp-tool%2FMakefile.help;h=d0f53cf5ece1713e88a5735f5932551e4c09c851;hb=3c7126b933c3ccb263648c59ffd010e97f2fb634;hp=b046f29d487c3634cb6a168346473dcb59db495b;hpb=9339f53ac84c4e8734e878e522e4cd174aca3453;p=sliver-openvswitch.git

diff --git a/planetlab/exp-tool/Makefile.help b/planetlab/exp-tool/Makefile.help
index b046f29d4..d0f53cf5e 100644
--- a/planetlab/exp-tool/Makefile.help
+++ b/planetlab/exp-tool/Makefile.help
@@ -2,6 +2,21 @@ in almost all cases below it is recommended to use the -j option to make
 which was the point with uing make in the first place
 so that maximum degree of parallelism can be reached
 
+**********************************************************
+Note: to get the greatest speedup from make -j you should also enable
+connection reuse in your ssh setup, e.g., by having the following lines
+in your .ssh/config:
+host *
+	ControlMaster auto
+	ControlPath ~/.ssh/ssh_mux_%h_%p_%r
+	ControlPersist 4h
+
+Please note, however, that maximum concurrent per-node reuse is usually
+set to something low (typically 10), and this is a problem if some node
+in your topology has many links. In this case you should raise that limit
+on the slivers, or limit makefile concurrency (e.g., by using make -j10).
+**********************************************************
+
 ==================== usual target
 make [init+all]
         shortcut for 'make init all'