rev 60542 : [mq]: 8245511-rev.3

   1 /*
   2  * Copyright (c) 2020, Amazon.com, Inc. or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #ifndef SHARE_VM_GC_G1_G1OLDGENALLOCATIONTRACKER_HPP
  26 #define SHARE_VM_GC_G1_G1OLDGENALLOCATIONTRACKER_HPP
  27 
  28 #include "gc/g1/heapRegion.hpp"
  29 #include "memory/allocation.hpp"
  30 
  31 class G1AdaptiveIHOPControl;
  32 
  33 // Track allocation details in the old generation.
  34 class G1OldGenAllocationTracker : public CHeapObj<mtGC> {
  35   // New bytes allocated in old gen between the end of the last GC and
  36   // the end of the GC before that. This includes humongous object allocation.
  37   size_t _last_period_old_bytes;
  38   // New bytes allocated in humongous regions between the end of the last GC and
  39   // the end of the GC before that.
  40   size_t _last_period_humongous_bytes;
  41 
  42   size_t _humongous_bytes_after_last_gc;
  43   size_t _humongous_bytes_after_penultimate_gc;
  44 
  45   size_t _allocated_bytes_since_last_gc;
  46   size_t _allocated_humongous_bytes_since_last_gc;
  47 


  48 public:
  49   G1OldGenAllocationTracker();
  50   // Add the given number of bytes to the total number of allocated bytes in the old gen.
  51   void add_allocated_bytes_since_last_gc(size_t bytes) { _allocated_bytes_since_last_gc += bytes; }
  52 
  53   void add_allocated_humongous_bytes_since_last_gc(size_t bytes) {
  54     _allocated_humongous_bytes_since_last_gc += bytes;
  55     _allocated_bytes_since_last_gc += bytes;
  56   }
  57 
  58   // Record a humongous allocation during a collection pause.
  59   // In g1CollectedHeap, when a humongous allocation fails, the heap will attempt
  60   // to trigger a GC and try to allocate the required bytes during it. These bytes
  61   // are then not counted in any mutator period but as survived bytes after GC.
  62   // Otherwise, they would distort our estimation for how many humongous bytes are
  63   // freed in a mutator period.
  64   void record_collection_pause_humongous_allocation(size_t bytes) {
  65     _humongous_bytes_after_last_gc += bytes;
  66   }
  67 
  68   size_t last_period_old_bytes() const { return _last_period_old_bytes; }
  69 
  70   // Reset stats after a collection.
  71   void reset_after_gc(size_t humongous_bytes_after_gc);
  72 
  73   // This is used by Adaptive IHOP to sample the old gen allocation rate.
  74   // Different from the regular old gen allocation rate, this method considers the
  75   // humongous objects that can be reclaimed early by young GCs. Since we cannot
  76   // track the life cycle of individual humongous objects, we assume that such
  77   // objects were all newly allocated and not survivors, unless more were
  78   // reclaimed than allocated.
  79   size_t last_period_net_survived_old_bytes() const;
  80 };
  81 
  82 #endif // SHARE_VM_GC_G1_G1OLDGENALLOCATIONTRACKER_HPP
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