main: suggest thrd_yield() for -y fairness

diff --git a/main.cc b/main.cc
index 8416a79c88db8b35b5d706413d36da8160b3afc0..d489d96eb459b5263d6d8a4032e31f39c28127c9 100644 (file)
--- a/main.cc
+++ b/main.cc
@@ -63,7 +63,8 @@ static void print_usage(const char *program_name, struct model_params *params)
 "                              Default: %d\n"
 "-S, --fvslop=NUM            Future value expiration sloppiness.\n"
 "                              Default: %u\n"
-"-y, --yield                 Enable CHESS-like yield-based fairness support.\n"
+"-y, --yield                 Enable CHESS-like yield-based fairness support\n"
+"                              (requires thrd_yield() in test program).\n"
 "                              Default: %s\n"
 "-Y, --yieldblock            Prohibit an execution from running a yield.\n"
 "                              Default: %s\n"