view src/share/vm/interpreter/bytecodeHistogram.cpp @ 20543: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
author tschatzl
date Fri, 10 Oct 2014 15:51:58 +0200
parents f95d63e2154a
children
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/*
 * Copyright (c) 1997, 2010, 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.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 *
 */

#include "precompiled.hpp"
#include "interpreter/bytecodeHistogram.hpp"
#include "memory/resourceArea.hpp"
#include "runtime/os.hpp"
#include "utilities/growableArray.hpp"

// ------------------------------------------------------------------------------------------------
// Non-product code
#ifndef PRODUCT

// Implementation of BytecodeCounter

int   BytecodeCounter::_counter_value = 0;
jlong BytecodeCounter::_reset_time    = 0;


void BytecodeCounter::reset() {
  _counter_value = 0;
  _reset_time    = os::elapsed_counter();
}


double BytecodeCounter::elapsed_time() {
  return (double)(os::elapsed_counter() - _reset_time) / (double)os::elapsed_frequency();
}


double BytecodeCounter::frequency() {
  return (double)counter_value() / elapsed_time();
}


void BytecodeCounter::print() {
  tty->print_cr(
    "%d bytecodes executed in %.1fs (%.3fMHz)",
    counter_value(),
    elapsed_time(),
    frequency() / 1000000.0
  );
}


// Helper class for sorting

class HistoEntry: public ResourceObj {
 private:
  int             _index;
  int             _count;

 public:
  HistoEntry(int index, int count)                         { _index = index; _count = count; }
  int             index() const                            { return _index; }
  int             count() const                            { return _count; }

  static int      compare(HistoEntry** x, HistoEntry** y)  { return (*x)->count() - (*y)->count(); }
};


// Helper functions

static GrowableArray<HistoEntry*>* sorted_array(int* array, int length) {
  GrowableArray<HistoEntry*>* a = new GrowableArray<HistoEntry*>(length);
  int i = length;
  while (i-- > 0) a->append(new HistoEntry(i, array[i]));
  a->sort(HistoEntry::compare);
  return a;
}


static int total_count(GrowableArray<HistoEntry*>* profile) {
  int sum = 0;
  int i = profile->length();
  while (i-- > 0) sum += profile->at(i)->count();
  return sum;
}


static const char* name_for(int i) {
  return Bytecodes::is_defined(i) ? Bytecodes::name(Bytecodes::cast(i)) : "xxxunusedxxx";
}


// Implementation of BytecodeHistogram

int BytecodeHistogram::_counters[Bytecodes::number_of_codes];


void BytecodeHistogram::reset() {
  int i = Bytecodes::number_of_codes;
  while (i-- > 0) _counters[i] = 0;
}


void BytecodeHistogram::print(float cutoff) {
  ResourceMark rm;
  GrowableArray<HistoEntry*>* profile = sorted_array(_counters, Bytecodes::number_of_codes);
  // print profile
  int tot     = total_count(profile);
  int abs_sum = 0;
  tty->cr();   //0123456789012345678901234567890123456789012345678901234567890123456789
  tty->print_cr("Histogram of %d executed bytecodes:", tot);
  tty->cr();
  tty->print_cr("  absolute  relative  code    name");
  tty->print_cr("----------------------------------------------------------------------");
  int i = profile->length();
  while (i-- > 0) {
    HistoEntry* e = profile->at(i);
    int       abs = e->count();
    float     rel = abs * 100.0F / tot;
    if (cutoff <= rel) {
      tty->print_cr("%10d  %7.2f%%    %02x    %s", abs, rel, e->index(), name_for(e->index()));
      abs_sum += abs;
    }
  }
  tty->print_cr("----------------------------------------------------------------------");
  float rel_sum = abs_sum * 100.0F / tot;
  tty->print_cr("%10d  %7.2f%%    (cutoff = %.2f%%)", abs_sum, rel_sum, cutoff);
  tty->cr();
}


// Implementation of BytecodePairHistogram

int BytecodePairHistogram::_index;
int BytecodePairHistogram::_counters[BytecodePairHistogram::number_of_pairs];


void BytecodePairHistogram::reset() {
  _index = Bytecodes::_nop << log2_number_of_codes;

  int i = number_of_pairs;
  while (i-- > 0) _counters[i] = 0;
}


void BytecodePairHistogram::print(float cutoff) {
  ResourceMark rm;
  GrowableArray<HistoEntry*>* profile = sorted_array(_counters, number_of_pairs);
  // print profile
  int tot     = total_count(profile);
  int abs_sum = 0;
  tty->cr();   //0123456789012345678901234567890123456789012345678901234567890123456789
  tty->print_cr("Histogram of %d executed bytecode pairs:", tot);
  tty->cr();
  tty->print_cr("  absolute  relative    codes    1st bytecode        2nd bytecode");
  tty->print_cr("----------------------------------------------------------------------");
  int i = profile->length();
  while (i-- > 0) {
    HistoEntry* e = profile->at(i);
    int       abs = e->count();
    float     rel = abs * 100.0F / tot;
    if (cutoff <= rel) {
      int   c1 = e->index() % number_of_codes;
      int   c2 = e->index() / number_of_codes;
      tty->print_cr("%10d   %6.3f%%    %02x %02x    %-19s %s", abs, rel, c1, c2, name_for(c1), name_for(c2));
      abs_sum += abs;
    }
  }
  tty->print_cr("----------------------------------------------------------------------");
  float rel_sum = abs_sum * 100.0F / tot;
  tty->print_cr("%10d   %6.3f%%    (cutoff = %.3f%%)", abs_sum, rel_sum, cutoff);
  tty->cr();
}

#endif