1 /*
2 * Copyright (c) 2014, 2019, 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/g1NUMA.inline.hpp"
27 #include "gc/g1/g1PageBasedVirtualSpace.hpp"
28 #include "gc/shared/workgroup.hpp"
29 #include "oops/markWord.hpp"
30 #include "oops/oop.inline.hpp"
31 #include "runtime/atomic.hpp"
32 #include "runtime/os.inline.hpp"
33 #include "services/memTracker.hpp"
34 #include "utilities/align.hpp"
35 #include "utilities/bitMap.inline.hpp"
36
37 G1PageBasedVirtualSpace::G1PageBasedVirtualSpace(ReservedSpace rs, size_t used_size, size_t page_size, MemoryType type) :
38 _low_boundary(NULL), _high_boundary(NULL), _tail_size(0), _page_size(0),
39 _committed(mtGC), _dirty(mtGC), _special(false), _executable(false), _numa(NULL) {
40 initialize_with_page_size(rs, used_size, page_size, type);
41 }
42
43 void G1PageBasedVirtualSpace::initialize_with_page_size(ReservedSpace rs, size_t used_size, size_t page_size, MemoryType type) {
44 guarantee(rs.is_reserved(), "Given reserved space must have been reserved already.");
45
46 vmassert(_low_boundary == NULL, "VirtualSpace already initialized");
47 vmassert(page_size > 0, "Page size must be non-zero.");
48
49 guarantee(is_aligned(rs.base(), page_size),
50 "Reserved space base " PTR_FORMAT " is not aligned to requested page size " SIZE_FORMAT, p2i(rs.base()), page_size);
51 guarantee(is_aligned(used_size, os::vm_page_size()),
52 "Given used reserved space size needs to be OS page size aligned (%d bytes) but is " SIZE_FORMAT, os::vm_page_size(), used_size);
53 guarantee(used_size <= rs.size(),
54 "Used size of reserved space " SIZE_FORMAT " bytes is smaller than reservation at " SIZE_FORMAT " bytes", used_size, rs.size());
55 guarantee(is_aligned(rs.size(), page_size),
56 "Expected that the virtual space is size aligned, but " SIZE_FORMAT " is not aligned to page size " SIZE_FORMAT, rs.size(), page_size);
57
58 _low_boundary = rs.base();
59 _high_boundary = _low_boundary + used_size;
60
61 _special = rs.special();
62 _executable = rs.executable();
63
64 _page_size = page_size;
65
66 vmassert(_committed.size() == 0, "virtual space initialized more than once");
67 BitMap::idx_t size_in_pages = rs.size() / page_size;
68 _committed.initialize(size_in_pages);
69 if (_special) {
70 _dirty.initialize(size_in_pages);
71 }
72
73 _tail_size = used_size % _page_size;
74
75 // Set _numa only if:
76 // 1) This space is for java heap.
77 // 2) There are multiple memory nodes because some OSes allow enabling UseNUMA.
78 if (type == mtJavaHeap && G1MemoryNodeManager::mgr()->num_active_nodes() > 1) {
79 _numa = G1NUMA::numa();
80 }
81 }
82
83 G1PageBasedVirtualSpace::~G1PageBasedVirtualSpace() {
84 // This does not release memory it never reserved.
85 // Caller must release via rs.release();
86 _low_boundary = NULL;
87 _high_boundary = NULL;
88 _special = false;
89 _executable = false;
90 _page_size = 0;
91 _tail_size = 0;
92 _numa = NULL;
93 }
94
95 size_t G1PageBasedVirtualSpace::committed_size() const {
96 size_t result = _committed.count_one_bits() * _page_size;
97 // The last page might not be in full.
98 if (is_last_page_partial() && _committed.at(_committed.size() - 1)) {
99 result -= _page_size - _tail_size;
100 }
101 return result;
102 }
103
104 size_t G1PageBasedVirtualSpace::reserved_size() const {
105 return pointer_delta(_high_boundary, _low_boundary, sizeof(char));
106 }
107
108 size_t G1PageBasedVirtualSpace::uncommitted_size() const {
109 return reserved_size() - committed_size();
110 }
111
112 void G1PageBasedVirtualSpace::commit_and_set_special() {
113 commit_internal(addr_to_page_index(_low_boundary), addr_to_page_index(_high_boundary));
114 _special = true;
115 _dirty.initialize(reserved_size()/_page_size);
116 }
117
118 size_t G1PageBasedVirtualSpace::addr_to_page_index(char* addr) const {
119 return (addr - _low_boundary) / _page_size;
120 }
121
122 bool G1PageBasedVirtualSpace::is_area_committed(size_t start_page, size_t size_in_pages) const {
123 size_t end_page = start_page + size_in_pages;
124 return _committed.get_next_zero_offset(start_page, end_page) >= end_page;
125 }
126
127 bool G1PageBasedVirtualSpace::is_area_uncommitted(size_t start_page, size_t size_in_pages) const {
128 size_t end_page = start_page + size_in_pages;
129 return _committed.get_next_one_offset(start_page, end_page) >= end_page;
130 }
131
132 char* G1PageBasedVirtualSpace::page_start(size_t index) const {
133 return _low_boundary + index * _page_size;
134 }
135
136 bool G1PageBasedVirtualSpace::is_after_last_page(size_t index) const {
137 guarantee(index <= _committed.size(),
138 "Given boundary page " SIZE_FORMAT " is beyond managed page count " SIZE_FORMAT, index, _committed.size());
139 return index == _committed.size();
140 }
141
142 void G1PageBasedVirtualSpace::commit_preferred_pages(size_t start, size_t num_pages) {
143 vmassert(num_pages > 0, "No full pages to commit");
144 vmassert(start + num_pages <= _committed.size(),
145 "Tried to commit area from page " SIZE_FORMAT " to page " SIZE_FORMAT " "
146 "that is outside of managed space of " SIZE_FORMAT " pages",
147 start, start + num_pages, _committed.size());
148
149 char* start_addr = page_start(start);
150 size_t size = num_pages * _page_size;
151
152 os::commit_memory_or_exit(start_addr, size, _page_size, _executable,
153 err_msg("Failed to commit area from " PTR_FORMAT " to " PTR_FORMAT " of length " SIZE_FORMAT ".",
154 p2i(start_addr), p2i(start_addr + size), size));
155 }
156
157 void G1PageBasedVirtualSpace::commit_tail() {
158 vmassert(_tail_size > 0, "The size of the tail area must be > 0 when reaching here");
159
160 char* const aligned_end_address = align_down(_high_boundary, _page_size);
161 os::commit_memory_or_exit(aligned_end_address, _tail_size, os::vm_page_size(), _executable,
162 err_msg("Failed to commit tail area from " PTR_FORMAT " to " PTR_FORMAT " of length " SIZE_FORMAT ".",
163 p2i(aligned_end_address), p2i(_high_boundary), _tail_size));
164 }
165
166 void G1PageBasedVirtualSpace::commit_internal(size_t start_page, size_t end_page) {
167 guarantee(start_page < end_page,
168 "Given start page " SIZE_FORMAT " is larger or equal to end page " SIZE_FORMAT, start_page, end_page);
169 guarantee(end_page <= _committed.size(),
170 "Given end page " SIZE_FORMAT " is beyond end of managed page amount of " SIZE_FORMAT, end_page, _committed.size());
171
172 size_t pages = end_page - start_page;
173 bool need_to_commit_tail = is_after_last_page(end_page) && is_last_page_partial();
174
175 // If we have to commit some (partial) tail area, decrease the amount of pages to avoid
176 // committing that in the full-page commit code.
177 if (need_to_commit_tail) {
178 pages--;
179 }
180
181 if (pages > 0) {
182 commit_preferred_pages(start_page, pages);
183 }
184
185 if (need_to_commit_tail) {
186 commit_tail();
187 }
188 }
189
190 char* G1PageBasedVirtualSpace::bounded_end_addr(size_t end_page) const {
191 return MIN2(_high_boundary, page_start(end_page));
192 }
193
194 void G1PageBasedVirtualSpace::pretouch_internal(size_t start_page, size_t end_page) {
195 guarantee(start_page < end_page,
196 "Given start page " SIZE_FORMAT " is larger or equal to end page " SIZE_FORMAT, start_page, end_page);
197
198 os::pretouch_memory(page_start(start_page), bounded_end_addr(end_page), _page_size);
199 }
200
201 bool G1PageBasedVirtualSpace::commit(size_t start_page, size_t size_in_pages) {
202 // We need to make sure to commit all pages covered by the given area.
203 guarantee(is_area_uncommitted(start_page, size_in_pages), "Specified area is not uncommitted");
204
205 bool zero_filled = true;
206 size_t end_page = start_page + size_in_pages;
207
208 if (_special) {
209 // Check for dirty pages and update zero_filled if any found.
210 if (_dirty.get_next_one_offset(start_page, end_page) < end_page) {
211 zero_filled = false;
212 _dirty.clear_range(start_page, end_page);
213 }
214 } else {
215 commit_internal(start_page, end_page);
216 }
217 _committed.set_range(start_page, end_page);
218
219 if (_numa != NULL) {
220 char* start_addr = page_start(start_page);
221 size_t size_in_bytes = size_in_pages * _page_size;
222 _numa->request_memory_on_node((address)start_addr, size_in_bytes);
223 }
224
225 return zero_filled;
226 }
227
228 void G1PageBasedVirtualSpace::uncommit_internal(size_t start_page, size_t end_page) {
229 guarantee(start_page < end_page,
230 "Given start page " SIZE_FORMAT " is larger or equal to end page " SIZE_FORMAT, start_page, end_page);
231
232 char* start_addr = page_start(start_page);
233 os::uncommit_memory(start_addr, pointer_delta(bounded_end_addr(end_page), start_addr, sizeof(char)));
234 }
235
236 void G1PageBasedVirtualSpace::uncommit(size_t start_page, size_t size_in_pages) {
237 guarantee(is_area_committed(start_page, size_in_pages), "checking");
238
239 size_t end_page = start_page + size_in_pages;
240 if (_special) {
241 // Mark that memory is dirty. If committed again the memory might
242 // need to be cleared explicitly.
243 _dirty.set_range(start_page, end_page);
244 } else {
245 uncommit_internal(start_page, end_page);
246 }
247
248 _committed.clear_range(start_page, end_page);
249 }
250
251 class G1PretouchTask : public AbstractGangTask {
252 private:
253 char* volatile _cur_addr;
254 char* const _start_addr;
255 char* const _end_addr;
256 size_t _page_size;
257 public:
258 G1PretouchTask(char* start_address, char* end_address, size_t page_size) :
259 AbstractGangTask("G1 PreTouch"),
260 _cur_addr(start_address),
261 _start_addr(start_address),
262 _end_addr(end_address),
263 _page_size(0) {
264 #ifdef LINUX
265 _page_size = UseTransparentHugePages ? (size_t)os::vm_page_size(): page_size;
266 #else
267 _page_size = page_size;
268 #endif
269 }
270
271 virtual void work(uint worker_id) {
272 size_t const actual_chunk_size = MAX2(chunk_size(), _page_size);
273 while (true) {
274 char* touch_addr = Atomic::add(actual_chunk_size, &_cur_addr) - actual_chunk_size;
275 if (touch_addr < _start_addr || touch_addr >= _end_addr) {
276 break;
277 }
278 char* end_addr = touch_addr + MIN2(actual_chunk_size, pointer_delta(_end_addr, touch_addr, sizeof(char)));
279 os::pretouch_memory(touch_addr, end_addr, _page_size);
280 }
281 }
282
283 static size_t chunk_size() { return PreTouchParallelChunkSize; }
284 };
285
286 void G1PageBasedVirtualSpace::pretouch(size_t start_page, size_t size_in_pages, WorkGang* pretouch_gang) {
287 G1PretouchTask cl(page_start(start_page), bounded_end_addr(start_page + size_in_pages), _page_size);
288
289 if (pretouch_gang != NULL) {
290 size_t num_chunks = MAX2((size_t)1, size_in_pages * _page_size / MAX2(G1PretouchTask::chunk_size(), _page_size));
291
292 uint num_workers = MIN2((uint)num_chunks, pretouch_gang->active_workers());
293 log_debug(gc, heap)("Running %s with %u workers for " SIZE_FORMAT " work units pre-touching " SIZE_FORMAT "B.",
294 cl.name(), num_workers, num_chunks, size_in_pages * _page_size);
295 pretouch_gang->run_task(&cl, num_workers);
296 } else {
297 log_debug(gc, heap)("Running %s pre-touching " SIZE_FORMAT "B.",
298 cl.name(), size_in_pages * _page_size);
299 cl.work(0);
300 }
301 }
302
303 bool G1PageBasedVirtualSpace::contains(const void* p) const {
304 return _low_boundary <= (const char*) p && (const char*) p < _high_boundary;
305 }
306
307 #ifndef PRODUCT
308 void G1PageBasedVirtualSpace::print_on(outputStream* out) {
309 out->print ("Virtual space:");
310 if (_special) out->print(" (pinned in memory)");
311 out->cr();
312 out->print_cr(" - committed: " SIZE_FORMAT, committed_size());
313 out->print_cr(" - reserved: " SIZE_FORMAT, reserved_size());
314 out->print_cr(" - preferred page size: " SIZE_FORMAT, _page_size);
315 out->print_cr(" - [low_b, high_b]: [" PTR_FORMAT ", " PTR_FORMAT "]", p2i(_low_boundary), p2i(_high_boundary));
316 }
317
318 void G1PageBasedVirtualSpace::print() {
319 print_on(tty);
320 }
321 #endif