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
30 G1YoungGenSizer::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
71 uint 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
76 uint 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
81 void 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
111 void 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
125 void 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 }