--- old/src/share/vm/logging/logOutput.cpp	2016-03-31 21:47:55.498582176 +0900
+++ new/src/share/vm/logging/logOutput.cpp	2016-03-31 21:47:55.338582801 +0900
@@ -57,19 +57,23 @@
 
   size_t offset = strlen(_config_string);
   for (;;) {
-    int ret = ts->label(_config_string + offset, _config_string_buffer_size - offset, "+");
+    size_t buffer_offset = (offset == 0) ? 0 : (offset + 1);
+    int ret = ts->label(_config_string + buffer_offset, _config_string_buffer_size - buffer_offset, "+");
     if (ret == -1) {
       // Double the buffer size and retry
       _config_string_buffer_size *= 2;
       _config_string = REALLOC_C_HEAP_ARRAY(char, _config_string, _config_string_buffer_size, mtLogging);
       continue;
     }
+    if (offset > 0) {
+      _config_string[offset] = ',';
+    }
     break;
   };
 
   offset = strlen(_config_string);
   for (;;) {
-    int ret = jio_snprintf(_config_string + offset, _config_string_buffer_size - offset, "=%s,", LogLevel::name(level));
+    int ret = jio_snprintf(_config_string + offset, _config_string_buffer_size - offset, "=%s", LogLevel::name(level));
     if (ret == -1) {
       _config_string_buffer_size *= 2;
       _config_string = REALLOC_C_HEAP_ARRAY(char, _config_string, _config_string_buffer_size, mtLogging);