jdk8-mips64-public/hotspot: src/share/vm/gc_implementation/g1/survRateGroup.cpp@e7d0505c8a30 (annotated)

src/share/vm/gc_implementation/g1/survRateGroup.cpp@e7d0505c8a30 (annotated)

src/share/vm/gc_implementation/g1/survRateGroup.cpp

Fri, 10 Oct 2014 15:51:58 +0200

author: tschatzl
date: Fri, 10 Oct 2014 15:51:58 +0200
changeset 7257: e7d0505c8a30
parent 6680: 78bbf4d43a14
child 6876: 710a3c8b516e
permissions: -rw-r--r--

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

 /*
  * Copyright (c) 2001, 2014, 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 "gc_implementation/g1/g1CollectedHeap.inline.hpp"
 #include "gc_implementation/g1/g1CollectorPolicy.hpp"
 #include "gc_implementation/g1/heapRegion.hpp"
 #include "gc_implementation/g1/survRateGroup.hpp"
 #include "memory/allocation.hpp"
 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
 SurvRateGroup::SurvRateGroup(G1CollectorPolicy* g1p,
                              const char* name,
                              size_t summary_surv_rates_len) :
     _g1p(g1p), _name(name),
     _summary_surv_rates_len(summary_surv_rates_len),
     _summary_surv_rates_max_len(0),
     _summary_surv_rates(NULL),
     _surv_rate(NULL),
     _accum_surv_rate_pred(NULL),
     _surv_rate_pred(NULL),
     _stats_arrays_length(0) {
   reset();
   if (summary_surv_rates_len > 0) {
     size_t length = summary_surv_rates_len;
       _summary_surv_rates = NEW_C_HEAP_ARRAY(NumberSeq*, length, mtGC);
     for (size_t i = 0; i < length; ++i) {
       _summary_surv_rates[i] = new NumberSeq();
     }
   }
   start_adding_regions();
 }
 void SurvRateGroup::reset() {
   _all_regions_allocated = 0;
   _setup_seq_num         = 0;
   _accum_surv_rate       = 0.0;
   _last_pred             = 0.0;
   // the following will set up the arrays with length 1
   _region_num            = 1;
   // The call to stop_adding_regions() will use "new" to refill
   // the _surv_rate_pred array, so we need to make sure to call
   // "delete".
   for (size_t i = 0; i < _stats_arrays_length; ++i) {
     delete _surv_rate_pred[i];
   }
   _stats_arrays_length = 0;
   stop_adding_regions();
   guarantee( _stats_arrays_length == 1, "invariant" );
   guarantee( _surv_rate_pred[0] != NULL, "invariant" );
   _surv_rate_pred[0]->add(0.4);
   all_surviving_words_recorded(false);
   _region_num = 0;
 }
 void
 SurvRateGroup::start_adding_regions() {
   _setup_seq_num   = _stats_arrays_length;
   _region_num      = 0;
   _accum_surv_rate = 0.0;
 }
 void
 SurvRateGroup::stop_adding_regions() {
   if (_region_num > _stats_arrays_length) {
     double* old_surv_rate = _surv_rate;
     double* old_accum_surv_rate_pred = _accum_surv_rate_pred;
     TruncatedSeq** old_surv_rate_pred = _surv_rate_pred;
     _surv_rate = NEW_C_HEAP_ARRAY(double, _region_num, mtGC);
     _accum_surv_rate_pred = NEW_C_HEAP_ARRAY(double, _region_num, mtGC);
     _surv_rate_pred = NEW_C_HEAP_ARRAY(TruncatedSeq*, _region_num, mtGC);
     for (size_t i = 0; i < _stats_arrays_length; ++i) {
       _surv_rate_pred[i] = old_surv_rate_pred[i];
     }
     for (size_t i = _stats_arrays_length; i < _region_num; ++i) {
       _surv_rate_pred[i] = new TruncatedSeq(10);
     }
     _stats_arrays_length = _region_num;
     if (old_surv_rate != NULL) {
       FREE_C_HEAP_ARRAY(double, old_surv_rate, mtGC);
     }
     if (old_accum_surv_rate_pred != NULL) {
       FREE_C_HEAP_ARRAY(double, old_accum_surv_rate_pred, mtGC);
     }
     if (old_surv_rate_pred != NULL) {
       FREE_C_HEAP_ARRAY(TruncatedSeq*, old_surv_rate_pred, mtGC);
     }
   }
   for (size_t i = 0; i < _stats_arrays_length; ++i) {
     _surv_rate[i] = 0.0;
   }
 }
 double
 SurvRateGroup::accum_surv_rate(size_t adjustment) {
   // we might relax this one in the future...
   guarantee( adjustment == 0 || adjustment == 1, "pre-condition" );
   double ret = _accum_surv_rate;
   if (adjustment > 0) {
     TruncatedSeq* seq = get_seq(_region_num+1);
     double surv_rate = _g1p->get_new_prediction(seq);
     ret += surv_rate;
   }
   return ret;
 }
 int
 SurvRateGroup::next_age_index() {
   TruncatedSeq* seq = get_seq(_region_num);
   double surv_rate = _g1p->get_new_prediction(seq);
   _accum_surv_rate += surv_rate;
   ++_region_num;
   return (int) ++_all_regions_allocated;
 }
 void
 SurvRateGroup::record_surviving_words(int age_in_group, size_t surv_words) {
   guarantee( 0 <= age_in_group && (size_t) age_in_group < _region_num,
              "pre-condition" );
   guarantee( _surv_rate[age_in_group] <= 0.00001,
              "should only update each slot once" );
   double surv_rate = (double) surv_words / (double) HeapRegion::GrainWords;
   _surv_rate[age_in_group] = surv_rate;
   _surv_rate_pred[age_in_group]->add(surv_rate);
   if ((size_t)age_in_group < _summary_surv_rates_len) {
     _summary_surv_rates[age_in_group]->add(surv_rate);
     if ((size_t)(age_in_group+1) > _summary_surv_rates_max_len)
       _summary_surv_rates_max_len = age_in_group+1;
   }
 }
 void
 SurvRateGroup::all_surviving_words_recorded(bool propagate) {
   if (propagate && _region_num > 0) { // conservative
     double surv_rate = _surv_rate_pred[_region_num-1]->last();
     for (size_t i = _region_num; i < _stats_arrays_length; ++i) {
       guarantee( _surv_rate[i] <= 0.00001,
                  "the slot should not have been updated" );
       _surv_rate_pred[i]->add(surv_rate);
     }
   }
   double accum = 0.0;
   double pred = 0.0;
   for (size_t i = 0; i < _stats_arrays_length; ++i) {
     pred = _g1p->get_new_prediction(_surv_rate_pred[i]);
     if (pred > 1.0) pred = 1.0;
     accum += pred;
     _accum_surv_rate_pred[i] = accum;
     // gclog_or_tty->print_cr("age %3d, accum %10.2lf", i, accum);
   }
   _last_pred = pred;
 }
 #ifndef PRODUCT
 void
 SurvRateGroup::print() {
   gclog_or_tty->print_cr("Surv Rate Group: %s (%d entries)",
                 _name, _region_num);
   for (size_t i = 0; i < _region_num; ++i) {
     gclog_or_tty->print_cr("    age %4d   surv rate %6.2lf %%   pred %6.2lf %%",
                   i, _surv_rate[i] * 100.0,
                   _g1p->get_new_prediction(_surv_rate_pred[i]) * 100.0);
   }
 }
 void
 SurvRateGroup::print_surv_rate_summary() {
   size_t length = _summary_surv_rates_max_len;
   if (length == 0)
     return;
   gclog_or_tty->cr();
   gclog_or_tty->print_cr("%s Rate Summary (for up to age %d)", _name, length-1);
   gclog_or_tty->print_cr("      age range     survival rate (avg)      samples (avg)");
   gclog_or_tty->print_cr("  ---------------------------------------------------------");
   size_t index = 0;
   size_t limit = MIN2((int) length, 10);
   while (index < limit) {
     gclog_or_tty->print_cr("           %4d                 %6.2lf%%             %6.2lf",
                   index, _summary_surv_rates[index]->avg() * 100.0,
                   (double) _summary_surv_rates[index]->num());
     ++index;
   }
   gclog_or_tty->print_cr("  ---------------------------------------------------------");
   int num = 0;
   double sum = 0.0;
   int samples = 0;
   while (index < length) {
     ++num;
     sum += _summary_surv_rates[index]->avg() * 100.0;
     samples += _summary_surv_rates[index]->num();
     ++index;
     if (index == length || num % 10 == 0) {
       gclog_or_tty->print_cr("   %4d .. %4d                 %6.2lf%%             %6.2lf",
                     (index-1) / 10 * 10, index-1, sum / (double) num,
                     (double) samples / (double) num);
       sum = 0.0;
       num = 0;
       samples = 0;
     }
   }
   gclog_or_tty->print_cr("  ---------------------------------------------------------");
 }
 #endif // PRODUCT

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/gc_implementation/g1/survRateGroup.cpp@e7d0505c8a30 (annotated)

src/share/vm/gc_implementation/g1/survRateGroup.cpp