diff --git a/perf-regression/margo-p2p-bw.c b/perf-regression/margo-p2p-bw.c
index 6bb0e81ea8dd12c98768077be50296adde0e1ebb..a7b7608a8953f46c71dbb64311d1713cc77469ca 100644
--- a/perf-regression/margo-p2p-bw.c
+++ b/perf-regression/margo-p2p-bw.c
@@ -405,7 +405,8 @@ static void usage(void)
         "\t-n <na> - na transport\n"
         "\t[-c concurrency] - number of concurrent operations to issue with ULTs\n"
         "\t[-T <os threads] - number of dedicated operating system threads to run ULTs on\n"
-        "\t[-d filename] - enable diagnostics output \n"
+        "\t[-d filename] - enable diagnostics output\n"
+        "\t[-t client_progress_timeout,server_progress_timeout] # use \"-t 0,0\" to busy spin\n"
         "\t\texample: mpiexec -n 2 ./margo-p2p-bw -x 4096 -D 30 -n verbs://\n"
         "\t\t(must be run with exactly 2 processes\n");
     
diff --git a/perf-regression/margo-p2p-latency.c b/perf-regression/margo-p2p-latency.c
index 11b6ca07a665c19762efc9d712c992ca9d55336a..0ba9a91c0afc62ea0ad8dec0c589ff2072a40c42 100644
--- a/perf-regression/margo-p2p-latency.c
+++ b/perf-regression/margo-p2p-latency.c
@@ -293,7 +293,8 @@ static void usage(void)
         "margo-p2p-latency -i <iterations> -n <na>\n"
         "\t-i <iterations> - number of RPC iterations\n"
         "\t-n <na> - na transport\n"
-        "\t[-d filename] - enable diagnostics output \n"
+        "\t[-d filename] - enable diagnostics output\n"
+        "\t[-t client_progress_timeout,server_progress_timeout] # use \"-t 0,0\" to busy spin\n"
         "\t\texample: mpiexec -n 2 ./margo-p2p-latency -i 10000 -n verbs://\n"
         "\t\t(must be run with exactly 2 processes\n");