--- old/src/share/vm/runtime/arguments.cpp	Thu Aug 15 09:00:50 2013
+++ new/src/share/vm/runtime/arguments.cpp	Thu Aug 15 09:00:50 2013
@@ -1844,7 +1844,7 @@
         (NumberOfGCLogFiles == 0)  ||
         (GCLogFileSize == 0)) {
       jio_fprintf(defaultStream::output_stream(),
-                  "To enable GC log rotation, use -Xloggc:<filename> -XX:+UseGCLogFileRotation -XX:NumberOfGCLogFiles=<num_of_files> -XX:GCLogFileSize=<num_of_size>\n"
+                  "To enable GC log rotation, use -Xloggc:<filename> -XX:+UseGCLogFileRotation -XX:NumberOfGCLogFiles=<num_of_files> -XX:GCLogFileSize=<num_of_size>[k|K|m|M]\n"
                   "where num_of_file > 0 and num_of_size > 0\n"
                   "GC log rotation is turned off\n");
       UseGCLogFileRotation = false;
--- old/src/share/vm/utilities/ostream.cpp	Thu Aug 15 09:00:51 2013
+++ new/src/share/vm/utilities/ostream.cpp	Thu Aug 15 09:00:51 2013
@@ -423,6 +423,7 @@
   update_position(s, len);
 }
 
+#define EXTRACHARLEN 20
 rotatingFileStream::~rotatingFileStream() {
   if (_file != NULL) {
     if (_need_close) fclose(_file);
@@ -435,8 +436,12 @@
 rotatingFileStream::rotatingFileStream(const char* file_name) {
   _cur_file_num = 0;
   _bytes_written = 0L;
-  _file_name = NEW_C_HEAP_ARRAY(char, strlen(file_name)+10, mtInternal);
-  jio_snprintf(_file_name, strlen(file_name)+10, "%s.%d", file_name, _cur_file_num);
+  _file_name = NEW_C_HEAP_ARRAY(char, strlen(file_name) + EXTRACHARLEN, mtInternal);
+  if (NumberOfGCLogFiles == 1) {
+    jio_snprintf(_file_name, strlen(file_name) + EXTRACHARLEN, "%s", file_name);
+  } else {
+    jio_snprintf(_file_name, strlen(file_name) + EXTRACHARLEN, "%s.%d.current", file_name, _cur_file_num);
+  }
   _file = fopen(_file_name, "w");
   _need_close = true;
 }
@@ -444,8 +449,12 @@
 rotatingFileStream::rotatingFileStream(const char* file_name, const char* opentype) {
   _cur_file_num = 0;
   _bytes_written = 0L;
-  _file_name = NEW_C_HEAP_ARRAY(char, strlen(file_name)+10, mtInternal);
-  jio_snprintf(_file_name, strlen(file_name)+10, "%s.%d", file_name, _cur_file_num);
+  _file_name = NEW_C_HEAP_ARRAY(char, strlen(file_name) + EXTRACHARLEN, mtInternal);
+  if (NumberOfGCLogFiles == 1) {
+    jio_snprintf(_file_name, strlen(file_name) + EXTRACHARLEN, "%s", file_name);
+  } else {
+    jio_snprintf(_file_name, strlen(file_name) + EXTRACHARLEN, "%s.%d.current", file_name, _cur_file_num);
+  }
   _file = fopen(_file_name, opentype);
   _need_close = true;
 }
@@ -467,6 +476,10 @@
 // concurrent GC threads to run parallel with VMThread at safepoint, write and rotate_log
 // must be synchronized.
 void rotatingFileStream::rotate_log() {
+  char time_msg[256];
+  char time_str[64];
+  char renamed_file_name[256];
+
   if (_bytes_written < (jlong)GCLogFileSize) {
     return;
   }
@@ -484,20 +497,54 @@
     return;
   }
 
-  // rotate file in names file.0, file.1, file.2, ..., file.<MaxGCLogFileNumbers-1>
-  // close current file, rotate to next file
+  // rotate file in names file.0, file.1, ..., file.<MaxGCLogFileNumber - 1>
+  // current file name is like file.n.current, after reaches to maximum size,
+  // will be renamed to file.n 
+  size_t filename_len = strlen(Arguments::gc_log_filename());
   if (_file != NULL) {
-    _cur_file_num ++;
-    if (_cur_file_num >= NumberOfGCLogFiles) _cur_file_num = 0;
-    jio_snprintf(_file_name, strlen(Arguments::gc_log_filename()) + 10, "%s.%d",
+    jio_snprintf(renamed_file_name,  filename_len + EXTRACHARLEN, "%s.%d",
              Arguments::gc_log_filename(), _cur_file_num);
+    jio_snprintf(time_msg, sizeof(time_msg), "%s GC log file has reached the"
+                           " maximum size. Saved as %s\n",
+                           os::local_time_string((char *)time_str, sizeof(time_str)),
+                           renamed_file_name);
+    this->write(time_msg, strlen(time_msg));
     fclose(_file);
     _file = NULL;
+
+    bool can_rename = true;
+    if (access(renamed_file_name, NOT_WINDOWS(F_OK) WINDOWS_ONLY(0)) == 0) {
+      if (remove(renamed_file_name) != 0) {
+        warning("Could not remove existed file %s\n", renamed_file_name);
+        can_rename = false;
+      }
+    } 
+    if (can_rename && rename(_file_name, renamed_file_name) != 0) {
+      warning("Could not rename %s to %s\n", _file_name, renamed_file_name);
+    }
+    // current file name 
+    _cur_file_num++;
+    if (_cur_file_num > NumberOfGCLogFiles - 1) _cur_file_num = 0;
+    jio_snprintf(_file_name, filename_len + EXTRACHARLEN, "%s.%d.current",
+                 Arguments::gc_log_filename(), _cur_file_num);
   }
   _file = fopen(_file_name, "w");
   if (_file != NULL) {
     _bytes_written = 0L;
     _need_close = true;
+    // reuse renamed_file_name for time_msg
+    jio_snprintf(renamed_file_name, filename_len + EXTRACHARLEN,
+                 "%s.%d", Arguments::gc_log_filename(), _cur_file_num);
+    jio_snprintf(time_msg, sizeof(time_msg), "%s GC log file created %s\n",
+                           os::local_time_string((char *)time_str, sizeof(time_str)),
+                           renamed_file_name);
+    this->write(time_msg, strlen(time_msg));
+    // remove the existed file
+    if (access(renamed_file_name, NOT_WINDOWS(F_OK) WINDOWS_ONLY(0)) == 0) {
+      if (remove(renamed_file_name) != 0) {
+        warning("Could not remove existed file %s\n", renamed_file_name);
+      }
+    }
   } else {
     tty->print_cr("failed to open rotation log file %s due to %s\n",
                   _file_name, strerror(errno));