jdk8-mips64-public/hotspot: src/share/vm/gc_implementation/g1/g1RemSetSummary.hpp@e7d0505c8a30

8059758: Footprint regressions with JDK-8038423
Summary: Changes in JDK-8038423 always initialize (zero out) virtual memory used for auxiliary data structures. This causes a footprint regression for G1 in startup benchmarks. This is because they do not touch that memory at all, so the operating system does not actually commit these pages. The fix is to, if the initialization value of the data structures matches the default value of just committed memory (=0), do not do anything.
Reviewed-by: jwilhelm, brutisso

     1 /*

     2  * Copyright (c) 2013, Oracle and/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  */

    25 #ifndef SHARE_VM_GC_IMPLEMENTATION_G1_G1REMSETSUMMARY_HPP

    26 #define SHARE_VM_GC_IMPLEMENTATION_G1_G1REMSETSUMMARY_HPP

    28 #include "utilities/ostream.hpp"

    30 class G1RemSet;

    32 // A G1RemSetSummary manages statistical information about the G1RemSet

    34 class G1RemSetSummary VALUE_OBJ_CLASS_SPEC {

    35 private:

    36   friend class GetRSThreadVTimeClosure;

    38   G1RemSet* _remset;

    40   G1RemSet* remset() const {

    41     return _remset;

    42   }

    44   size_t _num_refined_cards;

    45   size_t _num_processed_buf_mutator;

    46   size_t _num_processed_buf_rs_threads;

    48   size_t _num_coarsenings;

    50   double* _rs_threads_vtimes;

    51   size_t _num_vtimes;

    53   double _sampling_thread_vtime;

    55   void set_rs_thread_vtime(uint thread, double value);

    56   void set_sampling_thread_vtime(double value) {

    57     _sampling_thread_vtime = value;

    58   }

    60   void free_and_null() {

    61     if (_rs_threads_vtimes) {

    62       FREE_C_HEAP_ARRAY(double, _rs_threads_vtimes, mtGC);

    63       _rs_threads_vtimes = NULL;

    64       _num_vtimes = 0;

    65     }

    66   }

    68   // update this summary with current data from various places

    69   void update();

    71 public:

    72   G1RemSetSummary() : _remset(NULL), _num_refined_cards(0),

    73     _num_processed_buf_mutator(0), _num_processed_buf_rs_threads(0), _num_coarsenings(0),

    74     _rs_threads_vtimes(NULL), _num_vtimes(0), _sampling_thread_vtime(0.0f) {

    75   }

    77   ~G1RemSetSummary() {

    78     free_and_null();

    79   }

    81   // set the counters in this summary to the values of the others

    82   void set(G1RemSetSummary* other);

    83   // subtract all counters from the other summary, and set them in the current

    84   void subtract_from(G1RemSetSummary* other);

    86   // initialize and get the first sampling

    87   void initialize(G1RemSet* remset);

    89   void print_on(outputStream* out);

    91   double rs_thread_vtime(uint thread) const;

    93   double sampling_thread_vtime() const {

    94     return _sampling_thread_vtime;

    95   }

    97   size_t num_concurrent_refined_cards() const {

    98     return _num_refined_cards;

    99   }

   101   size_t num_processed_buf_mutator() const {

   102     return _num_processed_buf_mutator;

   103   }

   105   size_t num_processed_buf_rs_threads() const {

   106     return _num_processed_buf_rs_threads;

   107   }

   109   size_t num_processed_buf_total() const {

   110     return num_processed_buf_mutator() + num_processed_buf_rs_threads();

   111   }

   113   size_t num_coarsenings() const {

   114     return _num_coarsenings;

   115   }

   116 };

   118 #endif // SHARE_VM_GC_IMPLEMENTATION_G1_G1REMSETSUMMARY_HPP

Mercurial > jdk8-mips64-public > hotspot / file revision

src/share/vm/gc_implementation/g1/g1RemSetSummary.hpp@e7d0505c8a30

src/share/vm/gc_implementation/g1/g1RemSetSummary.hpp