src/share/vm/gc/shared/plab.cpp

@@ -1,7 +1,7 @@
 /*
- * Copyright (c) 2001, 2016, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2001, 2017, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.

@@ -152,10 +152,21 @@
   }
 
   assert(is_object_aligned(max_size()) && min_size() <= max_size(),
          "PLAB clipping computation may be incorrect");
 
+  size_t plab_sz = adjust_desired_plab_sz_helper();
+  // Take historical weighted average
+  _filter.sample(plab_sz);
+  _desired_net_plab_sz = MAX2(min_size(), (size_t)_filter.average());
+
+  log_sizing(plab_sz, _desired_net_plab_sz);
+  // Clear accumulators for next round
+  reset();
+}
+
+size_t PLABStats::adjust_desired_plab_sz_helper() {
   if (_allocated == 0) {
     assert(_unused == 0,
            "Inconsistency in PLAB stats: "
            "_allocated: " SIZE_FORMAT ", "
            "_wasted: " SIZE_FORMAT ", "

@@ -171,13 +182,7 @@
     target_refills = 1;
   }
   size_t used = _allocated - _wasted - _unused;
   // Assumed to have 1 gc worker thread
   size_t recent_plab_sz = used / target_refills;
-  // Take historical weighted average
-  _filter.sample(recent_plab_sz);
-  _desired_net_plab_sz = MAX2(min_size(), (size_t)_filter.average());
-
-  log_sizing(recent_plab_sz, _desired_net_plab_sz);
-
-  reset();
+  return recent_plab_sz;
 }