relay: document -U in usage message
@@ -329,6 +329,7 @@ do_usage(char *name, int exitcode)
printf(" -L server max stalls, defaults to %d\n", maxstalls);
printf(" -S statistics sending interval in seconds, defaults to 60\n");
printf(" -B connection listen backlog, defaults to 32\n");
+ printf(" -U socket receive buffer size, max/min/default values depend on OS\n");
printf(" -T IO timeout in milliseconds for server connections, defaults to %d\n", iotimeout);
printf(" -m send statistics like carbon-cache.py, e.g. not cumulative\n");
printf(" -c characters to allow next to [A-Za-z0-9], defaults to -_:#\n");
