--- a/src/share/vm/runtime/sweeper.cpp	Thu Jan 16 14:25:51 2014 +0100
+++ b/src/share/vm/runtime/sweeper.cpp	Wed Jan 22 17:42:23 2014 -0800
@@ -129,6 +129,7 @@
 
 nmethod* NMethodSweeper::_current                      = NULL; // Current nmethod
 long     NMethodSweeper::_traversals                   = 0;    // Stack scan count, also sweep ID.
+long     NMethodSweeper::_total_nof_code_cache_sweeps  = 0;    // Total number of full sweeps of the code cache
 long     NMethodSweeper::_time_counter                 = 0;    // Virtual time used to periodically invoke sweeper
 long     NMethodSweeper::_last_sweep                   = 0;    // Value of _time_counter when the last sweep happened
 int      NMethodSweeper::_seen                         = 0;    // Nof. nmethod we have currently processed in current pass of CodeCache
@@ -143,13 +144,16 @@
                                                                //   1) alive       -> not_entrant
                                                                //   2) not_entrant -> zombie
                                                                //   3) zombie      -> marked_for_reclamation
+int    NMethodSweeper::_hotness_counter_reset_val       = 0;
 
-int   NMethodSweeper::_total_nof_methods_reclaimed     = 0;    // Accumulated nof methods flushed
-Tickspan NMethodSweeper::_total_time_sweeping;                 // Accumulated time sweeping
-Tickspan NMethodSweeper::_total_time_this_sweep;               // Total time this sweep
-Tickspan NMethodSweeper::_peak_sweep_time;                     // Peak time for a full sweep
-Tickspan NMethodSweeper::_peak_sweep_fraction_time;            // Peak time sweeping one fraction
-int   NMethodSweeper::_hotness_counter_reset_val       = 0;
+long   NMethodSweeper::_total_nof_methods_reclaimed     = 0;    // Accumulated nof methods flushed
+long   NMethodSweeper::_total_nof_c2_methods_reclaimed  = 0;    // Accumulated nof methods flushed
+size_t NMethodSweeper::_total_flushed_size              = 0;    // Total number of bytes flushed from the code cache
+Tickspan  NMethodSweeper::_total_time_sweeping;                 // Accumulated time sweeping
+Tickspan  NMethodSweeper::_total_time_this_sweep;               // Total time this sweep
+Tickspan  NMethodSweeper::_peak_sweep_time;                     // Peak time for a full sweep
+Tickspan  NMethodSweeper::_peak_sweep_fraction_time;            // Peak time sweeping one fraction
+
 
 
 class MarkActivationClosure: public CodeBlobClosure {
@@ -257,9 +261,14 @@
   // Large ReservedCodeCacheSize:   (e.g., 256M + code Cache is 90% full). The formula
   //                                              computes: (256 / 16) - 10 = 6.
   if (!_should_sweep) {
-    int time_since_last_sweep = _time_counter - _last_sweep;
-    double wait_until_next_sweep = (ReservedCodeCacheSize / (16 * M)) - time_since_last_sweep -
-                                CodeCache::reverse_free_ratio();
+    const int time_since_last_sweep = _time_counter - _last_sweep;
+    // ReservedCodeCacheSize has an 'unsigned' type. We need a 'signed' type for max_wait_time,
+    // since 'time_since_last_sweep' can be larger than 'max_wait_time'. If that happens using
+    // an unsigned type would cause an underflow (wait_until_next_sweep becomes a large positive
+    // value) that disables the intended periodic sweeps.
+    const int max_wait_time = ReservedCodeCacheSize / (16 * M);
+    double wait_until_next_sweep = max_wait_time - time_since_last_sweep - CodeCache::reverse_free_ratio();
+    assert(wait_until_next_sweep <= (double)max_wait_time, "Calculation of code cache sweeper interval is incorrect");
 
     if ((wait_until_next_sweep <= 0.0) || !CompileBroker::should_compile_new_jobs()) {
       _should_sweep = true;
@@ -287,6 +296,7 @@
 
     // We are done with sweeping the code cache once.
     if (_sweep_fractions_left == 0) {
+      _total_nof_code_cache_sweeps++;
       _last_sweep = _time_counter;
       // Reset flag; temporarily disables sweeper
       _should_sweep = false;
@@ -374,6 +384,7 @@
   _total_time_sweeping  += sweep_time;
   _total_time_this_sweep += sweep_time;
   _peak_sweep_fraction_time = MAX2(sweep_time, _peak_sweep_fraction_time);
+  _total_flushed_size += freed_memory;
   _total_nof_methods_reclaimed += _flushed_count;
 
   EventSweepCodeCache event(UNTIMED);
@@ -505,6 +516,9 @@
         tty->print_cr("### Nmethod %3d/" PTR_FORMAT " (marked for reclamation) being flushed", nm->compile_id(), nm);
       }
       freed_memory = nm->total_size();
+      if (nm->is_compiled_by_c2()) {
+        _total_nof_c2_methods_reclaimed++;
+      }
       release_nmethod(nm);
       _flushed_count++;
     } else {
@@ -543,6 +557,9 @@
       SWEEP(nm);
       // No inline caches will ever point to osr methods, so we can just remove it
       freed_memory = nm->total_size();
+      if (nm->is_compiled_by_c2()) {
+        _total_nof_c2_methods_reclaimed++;
+      }
       release_nmethod(nm);
       _flushed_count++;
     } else {
@@ -630,3 +647,13 @@
     xtty->end_elem();
   }
 }
+
+void NMethodSweeper::print() {
+  ttyLocker ttyl;
+  tty->print_cr("Code cache sweeper statistics:");
+  tty->print_cr("  Total sweep time:                %1.0lfms", (double)_total_time_sweeping.value()/1000000);
+  tty->print_cr("  Total number of full sweeps:     %ld", _total_nof_code_cache_sweeps);
+  tty->print_cr("  Total number of flushed methods: %ld(%ld C2 methods)", _total_nof_methods_reclaimed,
+                                                    _total_nof_c2_methods_reclaimed);
+  tty->print_cr("  Total size of flushed methods:   " SIZE_FORMAT "kB", _total_flushed_size/K);
+}