1 /*
2 * Copyright (c) 2014, 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/g1PageBasedVirtualSpace.hpp"
27 #include "oops/markOop.hpp"
28 #include "oops/oop.inline.hpp"
29 #include "runtime/os.inline.hpp"
30 #include "services/memTracker.hpp"
31 #include "utilities/bitMap.inline.hpp"
32
33 G1PageBasedVirtualSpace::G1PageBasedVirtualSpace(ReservedSpace rs, size_t used_size, size_t page_size) :
34 _low_boundary(NULL), _high_boundary(NULL), _committed(), _page_size(0), _special(false),
35 _dirty(), _executable(false) {
36 initialize_with_page_size(rs, used_size, page_size);
37 }
38
39 void G1PageBasedVirtualSpace::initialize_with_page_size(ReservedSpace rs, size_t used_size, size_t page_size) {
40 guarantee(rs.is_reserved(), "Given reserved space must have been reserved already.");
41
42 vmassert(_low_boundary == NULL, "VirtualSpace already initialized");
43 vmassert(page_size > 0, "Page size must be non-zero.");
44
45 guarantee(is_ptr_aligned(rs.base(), page_size),
46 "Reserved space base " PTR_FORMAT " is not aligned to requested page size " SIZE_FORMAT, p2i(rs.base()), page_size);
47 guarantee(is_size_aligned(used_size, os::vm_page_size()),
48 "Given used reserved space size needs to be OS page size aligned (%d bytes) but is " SIZE_FORMAT, os::vm_page_size(), used_size);
49 guarantee(used_size <= rs.size(),
50 "Used size of reserved space " SIZE_FORMAT " bytes is smaller than reservation at " SIZE_FORMAT " bytes", used_size, rs.size());
51 guarantee(is_size_aligned(rs.size(), page_size),
52 "Expected that the virtual space is size aligned, but " SIZE_FORMAT " is not aligned to page size " SIZE_FORMAT, rs.size(), page_size);
53
54 _low_boundary = rs.base();
55 _high_boundary = _low_boundary + used_size;
56
57 _special = rs.special();
58 _executable = rs.executable();
59
60 _page_size = page_size;
61
62 vmassert(_committed.size() == 0, "virtual space initialized more than once");
63 BitMap::idx_t size_in_pages = rs.size() / page_size;
64 _committed.initialize(size_in_pages);
65 if (_special) {
66 _dirty.initialize(size_in_pages);
67 }
68
69 _tail_size = used_size % _page_size;
70 }
71
72 G1PageBasedVirtualSpace::~G1PageBasedVirtualSpace() {
73 // This does not release memory it never reserved.
74 // Caller must release via rs.release();
75 _low_boundary = NULL;
76 _high_boundary = NULL;
77 _special = false;
78 _executable = false;
79 _page_size = 0;
80 _tail_size = 0;
81 }
82
83 size_t G1PageBasedVirtualSpace::committed_size() const {
84 size_t result = _committed.count_one_bits() * _page_size;
85 // The last page might not be in full.
86 if (is_last_page_partial() && _committed.at(_committed.size() - 1)) {
87 result -= _page_size - _tail_size;
88 }
89 return result;
90 }
91
92 size_t G1PageBasedVirtualSpace::reserved_size() const {
93 return pointer_delta(_high_boundary, _low_boundary, sizeof(char));
94 }
95
96 size_t G1PageBasedVirtualSpace::uncommitted_size() const {
97 return reserved_size() - committed_size();
98 }
99
100 size_t G1PageBasedVirtualSpace::addr_to_page_index(char* addr) const {
101 return (addr - _low_boundary) / _page_size;
102 }
103
104 bool G1PageBasedVirtualSpace::is_area_committed(size_t start_page, size_t size_in_pages) const {
105 size_t end_page = start_page + size_in_pages;
106 return _committed.get_next_zero_offset(start_page, end_page) >= end_page;
107 }
108
109 bool G1PageBasedVirtualSpace::is_area_uncommitted(size_t start_page, size_t size_in_pages) const {
110 size_t end_page = start_page + size_in_pages;
111 return _committed.get_next_one_offset(start_page, end_page) >= end_page;
112 }
113
114 char* G1PageBasedVirtualSpace::page_start(size_t index) const {
115 return _low_boundary + index * _page_size;
116 }
117
118 bool G1PageBasedVirtualSpace::is_after_last_page(size_t index) const {
119 guarantee(index <= _committed.size(),
120 "Given boundary page " SIZE_FORMAT " is beyond managed page count " SIZE_FORMAT, index, _committed.size());
121 return index == _committed.size();
122 }
123
124 void G1PageBasedVirtualSpace::commit_preferred_pages(size_t start, size_t num_pages) {
125 vmassert(num_pages > 0, "No full pages to commit");
126 vmassert(start + num_pages <= _committed.size(),
127 "Tried to commit area from page " SIZE_FORMAT " to page " SIZE_FORMAT " "
128 "that is outside of managed space of " SIZE_FORMAT " pages",
129 start, start + num_pages, _committed.size());
130
131 char* start_addr = page_start(start);
132 size_t size = num_pages * _page_size;
133
134 os::commit_memory_or_exit(start_addr, size, _page_size, _executable,
135 err_msg("Failed to commit area from " PTR_FORMAT " to " PTR_FORMAT " of length " SIZE_FORMAT ".",
136 p2i(start_addr), p2i(start_addr + size), size));
137 }
138
139 void G1PageBasedVirtualSpace::commit_tail() {
140 vmassert(_tail_size > 0, "The size of the tail area must be > 0 when reaching here");
141
142 char* const aligned_end_address = (char*)align_ptr_down(_high_boundary, _page_size);
143 os::commit_memory_or_exit(aligned_end_address, _tail_size, os::vm_page_size(), _executable,
144 err_msg("Failed to commit tail area from " PTR_FORMAT " to " PTR_FORMAT " of length " SIZE_FORMAT ".",
145 p2i(aligned_end_address), p2i(_high_boundary), _tail_size));
146 }
147
148 void G1PageBasedVirtualSpace::commit_internal(size_t start_page, size_t end_page) {
149 guarantee(start_page < end_page,
150 "Given start page " SIZE_FORMAT " is larger or equal to end page " SIZE_FORMAT, start_page, end_page);
151 guarantee(end_page <= _committed.size(),
152 "Given end page " SIZE_FORMAT " is beyond end of managed page amount of " SIZE_FORMAT, end_page, _committed.size());
153
154 size_t pages = end_page - start_page;
155 bool need_to_commit_tail = is_after_last_page(end_page) && is_last_page_partial();
156
157 // If we have to commit some (partial) tail area, decrease the amount of pages to avoid
158 // committing that in the full-page commit code.
159 if (need_to_commit_tail) {
160 pages--;
161 }
162
163 if (pages > 0) {
164 commit_preferred_pages(start_page, pages);
165 }
166
167 if (need_to_commit_tail) {
168 commit_tail();
169 }
170 }
171
172 char* G1PageBasedVirtualSpace::bounded_end_addr(size_t end_page) const {
173 return MIN2(_high_boundary, page_start(end_page));
174 }
175
176 void G1PageBasedVirtualSpace::pretouch_internal(size_t start_page, size_t end_page) {
177 guarantee(start_page < end_page,
178 "Given start page " SIZE_FORMAT " is larger or equal to end page " SIZE_FORMAT, start_page, end_page);
179
180 os::pretouch_memory(page_start(start_page), bounded_end_addr(end_page));
181 }
182
183 bool G1PageBasedVirtualSpace::commit(size_t start_page, size_t size_in_pages) {
184 // We need to make sure to commit all pages covered by the given area.
185 guarantee(is_area_uncommitted(start_page, size_in_pages), "Specified area is not uncommitted");
186
187 bool zero_filled = true;
188 size_t end_page = start_page + size_in_pages;
189
190 if (_special) {
191 // Check for dirty pages and update zero_filled if any found.
192 if (_dirty.get_next_one_offset(start_page, end_page) < end_page) {
193 zero_filled = false;
194 _dirty.clear_range(start_page, end_page);
195 }
196 } else {
197 commit_internal(start_page, end_page);
198 }
199 _committed.set_range(start_page, end_page);
200
201 if (AlwaysPreTouch) {
202 pretouch_internal(start_page, end_page);
203 }
204 return zero_filled;
205 }
206
207 void G1PageBasedVirtualSpace::uncommit_internal(size_t start_page, size_t end_page) {
208 guarantee(start_page < end_page,
209 "Given start page " SIZE_FORMAT " is larger or equal to end page " SIZE_FORMAT, start_page, end_page);
210
211 char* start_addr = page_start(start_page);
212 os::uncommit_memory(start_addr, pointer_delta(bounded_end_addr(end_page), start_addr, sizeof(char)));
213 }
214
215 void G1PageBasedVirtualSpace::uncommit(size_t start_page, size_t size_in_pages) {
216 guarantee(is_area_committed(start_page, size_in_pages), "checking");
217
218 size_t end_page = start_page + size_in_pages;
219 if (_special) {
220 // Mark that memory is dirty. If committed again the memory might
221 // need to be cleared explicitly.
222 _dirty.set_range(start_page, end_page);
223 } else {
224 uncommit_internal(start_page, end_page);
225 }
226
227 _committed.clear_range(start_page, end_page);
228 }
229
230 bool G1PageBasedVirtualSpace::contains(const void* p) const {
231 return _low_boundary <= (const char*) p && (const char*) p < _high_boundary;
232 }
233
234 #ifndef PRODUCT
235 void G1PageBasedVirtualSpace::print_on(outputStream* out) {
236 out->print ("Virtual space:");
237 if (_special) out->print(" (pinned in memory)");
238 out->cr();
239 out->print_cr(" - committed: " SIZE_FORMAT, committed_size());
240 out->print_cr(" - reserved: " SIZE_FORMAT, reserved_size());
241 out->print_cr(" - preferred page size: " SIZE_FORMAT, _page_size);
242 out->print_cr(" - [low_b, high_b]: [" PTR_FORMAT ", " PTR_FORMAT "]", p2i(_low_boundary), p2i(_high_boundary));
243 }
244
245 void G1PageBasedVirtualSpace::print() {
246 print_on(tty);
247 }
248 #endif