1/*
2 * Copyright (c) 2016, 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 */
24
25#include "precompiled.hpp"
26#include "gc/g1/g1YoungGenSizer.hpp"
27#include "gc/g1/heapRegion.hpp"
28#include "logging/log.hpp"
29
30G1YoungGenSizer::G1YoungGenSizer() : _sizer_kind(SizerDefaults), _adaptive_size(true),
31        _min_desired_young_length(0), _max_desired_young_length(0) {
32  if (FLAG_IS_CMDLINE(NewRatio)) {
33    if (FLAG_IS_CMDLINE(NewSize) || FLAG_IS_CMDLINE(MaxNewSize)) {
34      log_warning(gc, ergo)("-XX:NewSize and -XX:MaxNewSize override -XX:NewRatio");
35    } else {
36      _sizer_kind = SizerNewRatio;
37      _adaptive_size = false;
38      return;
39    }
40  }
41
42  if (NewSize > MaxNewSize) {
43    if (FLAG_IS_CMDLINE(MaxNewSize)) {
44      log_warning(gc, ergo)("NewSize (" SIZE_FORMAT "k) is greater than the MaxNewSize (" SIZE_FORMAT "k). "
45                            "A new max generation size of " SIZE_FORMAT "k will be used.",
46                            NewSize/K, MaxNewSize/K, NewSize/K);
47    }
48    FLAG_SET_ERGO(size_t, MaxNewSize, NewSize);
49  }
50
51  if (FLAG_IS_CMDLINE(NewSize)) {
52    _min_desired_young_length = MAX2((uint) (NewSize / HeapRegion::GrainBytes),
53                                     1U);
54    if (FLAG_IS_CMDLINE(MaxNewSize)) {
55      _max_desired_young_length =
56                             MAX2((uint) (MaxNewSize / HeapRegion::GrainBytes),
57                                  1U);
58      _sizer_kind = SizerMaxAndNewSize;
59      _adaptive_size = _min_desired_young_length != _max_desired_young_length;
60    } else {
61      _sizer_kind = SizerNewSizeOnly;
62    }
63  } else if (FLAG_IS_CMDLINE(MaxNewSize)) {
64    _max_desired_young_length =
65                             MAX2((uint) (MaxNewSize / HeapRegion::GrainBytes),
66                                  1U);
67    _sizer_kind = SizerMaxNewSizeOnly;
68  }
69}
70
71uint G1YoungGenSizer::calculate_default_min_length(uint new_number_of_heap_regions) {
72  uint default_value = (new_number_of_heap_regions * G1NewSizePercent) / 100;
73  return MAX2(1U, default_value);
74}
75
76uint G1YoungGenSizer::calculate_default_max_length(uint new_number_of_heap_regions) {
77  uint default_value = (new_number_of_heap_regions * G1MaxNewSizePercent) / 100;
78  return MAX2(1U, default_value);
79}
80
81void G1YoungGenSizer::recalculate_min_max_young_length(uint number_of_heap_regions, uint* min_young_length, uint* max_young_length) {
82  assert(number_of_heap_regions > 0, "Heap must be initialized");
83
84  switch (_sizer_kind) {
85    case SizerDefaults:
86      *min_young_length = calculate_default_min_length(number_of_heap_regions);
87      *max_young_length = calculate_default_max_length(number_of_heap_regions);
88      break;
89    case SizerNewSizeOnly:
90      *max_young_length = calculate_default_max_length(number_of_heap_regions);
91      *max_young_length = MAX2(*min_young_length, *max_young_length);
92      break;
93    case SizerMaxNewSizeOnly:
94      *min_young_length = calculate_default_min_length(number_of_heap_regions);
95      *min_young_length = MIN2(*min_young_length, *max_young_length);
96      break;
97    case SizerMaxAndNewSize:
98      // Do nothing. Values set on the command line, don't update them at runtime.
99      break;
100    case SizerNewRatio:
101      *min_young_length = number_of_heap_regions / (NewRatio + 1);
102      *max_young_length = *min_young_length;
103      break;
104    default:
105      ShouldNotReachHere();
106  }
107
108  assert(*min_young_length <= *max_young_length, "Invalid min/max young gen size values");
109}
110
111void G1YoungGenSizer::adjust_max_new_size(uint number_of_heap_regions) {
112
113  // We need to pass the desired values because recalculation may not update these
114  // values in some cases.
115  uint temp = _min_desired_young_length;
116  uint result = _max_desired_young_length;
117  recalculate_min_max_young_length(number_of_heap_regions, &temp, &result);
118
119  size_t max_young_size = result * HeapRegion::GrainBytes;
120  if (max_young_size != MaxNewSize) {
121    FLAG_SET_ERGO(size_t, MaxNewSize, max_young_size);
122  }
123}
124
125void G1YoungGenSizer::heap_size_changed(uint new_number_of_heap_regions) {
126  recalculate_min_max_young_length(new_number_of_heap_regions, &_min_desired_young_length,
127          &_max_desired_young_length);
128}
129