1 /*
2 * Copyright (c) 2015, 2018, 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 #include "precompiled.hpp"
25 #include "gc/shared/threadLocalAllocBuffer.inline.hpp"
26 #include "gc/z/zCollectedHeap.hpp"
27 #include "gc/z/zGlobals.hpp"
28 #include "gc/z/zHeap.inline.hpp"
29 #include "gc/z/zObjectAllocator.hpp"
30 #include "gc/z/zPage.inline.hpp"
31 #include "gc/z/zStat.hpp"
32 #include "gc/z/zThread.hpp"
33 #include "gc/z/zUtils.inline.hpp"
34 #include "logging/log.hpp"
35 #include "runtime/atomic.hpp"
36 #include "runtime/safepoint.hpp"
37 #include "runtime/thread.hpp"
38 #include "runtime/threadSMR.hpp"
39 #include "utilities/align.hpp"
40 #include "utilities/debug.hpp"
41
42 static const ZStatCounter ZCounterUndoObjectAllocationSucceeded("Memory", "Undo Object Allocation Succeeded", ZStatUnitOpsPerSecond);
43 static const ZStatCounter ZCounterUndoObjectAllocationFailed("Memory", "Undo Object Allocation Failed", ZStatUnitOpsPerSecond);
44 static const ZStatSubPhase ZSubPhasePauseRetireTLABS("Pause Retire TLABS");
45 static const ZStatSubPhase ZSubPhasePauseRemapTLABS("Pause Remap TLABS");
46
47 ZObjectAllocator::ZObjectAllocator(uint nworkers) :
48 _nworkers(nworkers),
49 _used(0),
50 _shared_medium_page(NULL),
51 _shared_small_page(NULL),
52 _worker_small_page(NULL) {}
53
54 ZPage* ZObjectAllocator::alloc_page(uint8_t type, size_t size, ZAllocationFlags flags) {
55 ZPage* const page = ZHeap::heap()->alloc_page(type, size, flags);
56 if (page != NULL) {
57 // Increment used bytes
58 Atomic::add(size, _used.addr());
59 }
60
61 return page;
62 }
63
64 uintptr_t ZObjectAllocator::alloc_object_in_shared_page(ZPage** shared_page,
65 uint8_t page_type,
66 size_t page_size,
67 size_t size,
68 ZAllocationFlags flags) {
69 uintptr_t addr = 0;
70 ZPage* page = *shared_page;
71
72 if (page != NULL) {
73 addr = page->alloc_object_atomic(size);
74 }
75
76 if (addr == 0) {
77 // Allocate new page
78 ZPage* const new_page = alloc_page(page_type, page_size, flags);
79 if (new_page != NULL) {
80 // Allocate object before installing the new page
81 addr = new_page->alloc_object(size);
82
83 retry:
84 // Install new page
85 ZPage* const prev_page = Atomic::cmpxchg(new_page, shared_page, page);
86 if (prev_page != page) {
87 if (prev_page == NULL) {
88 // Previous page was retired, retry installing the new page
89 page = prev_page;
90 goto retry;
91 }
92
93 // Another page already installed, try allocation there first
94 const uintptr_t prev_addr = prev_page->alloc_object_atomic(size);
95 if (prev_addr == 0) {
96 // Allocation failed, retry installing the new page
97 page = prev_page;
98 goto retry;
99 }
100
101 // Allocation succeeded in already installed page
102 addr = prev_addr;
103
104 // Undo new page allocation
105 ZHeap::heap()->undo_alloc_page(new_page);
106 }
107 }
108 }
109
110 return addr;
111 }
112
113 uintptr_t ZObjectAllocator::alloc_large_object(size_t size, ZAllocationFlags flags) {
114 assert(ZThread::is_java(), "Should be a Java thread");
115
116 uintptr_t addr = 0;
117
118 // Allocate new large page
119 const size_t page_size = align_up(size, ZPageSizeMin);
120 ZPage* const page = alloc_page(ZPageTypeLarge, page_size, flags);
121 if (page != NULL) {
122 // Allocate the object
123 addr = page->alloc_object(size);
124 }
125
126 return addr;
127 }
128
129 uintptr_t ZObjectAllocator::alloc_medium_object(size_t size, ZAllocationFlags flags) {
130 return alloc_object_in_shared_page(_shared_medium_page.addr(), ZPageTypeMedium, ZPageSizeMedium, size, flags);
131 }
132
133 uintptr_t ZObjectAllocator::alloc_small_object_from_nonworker(size_t size, ZAllocationFlags flags) {
134 assert(ZThread::is_java() || ZThread::is_vm(), "Should be a Java or VM thread");
135
136 // Non-worker small page allocation can never use the reserve
137 flags.set_no_reserve();
138
139 return alloc_object_in_shared_page(_shared_small_page.addr(), ZPageTypeSmall, ZPageSizeSmall, size, flags);
140 }
141
142 uintptr_t ZObjectAllocator::alloc_small_object_from_worker(size_t size, ZAllocationFlags flags) {
143 assert(ZThread::is_worker(), "Should be a worker thread");
144
145 ZPage* page = _worker_small_page.get();
146 uintptr_t addr = 0;
147
148 if (page != NULL) {
149 addr = page->alloc_object(size);
150 }
151
152 if (addr == 0) {
153 // Allocate new page
154 page = alloc_page(ZPageTypeSmall, ZPageSizeSmall, flags);
155 if (page != NULL) {
156 addr = page->alloc_object(size);
157 }
158 _worker_small_page.set(page);
159 }
160
161 return addr;
162 }
163
164 uintptr_t ZObjectAllocator::alloc_small_object(size_t size, ZAllocationFlags flags) {
165 if (flags.worker_thread()) {
166 return alloc_small_object_from_worker(size, flags);
167 } else {
168 return alloc_small_object_from_nonworker(size, flags);
169 }
170 }
171
172 uintptr_t ZObjectAllocator::alloc_object(size_t size, ZAllocationFlags flags) {
173 if (size <= ZObjectSizeLimitSmall) {
174 // Small
175 return alloc_small_object(size, flags);
176 } else if (size <= ZObjectSizeLimitMedium) {
177 // Medium
178 return alloc_medium_object(size, flags);
179 } else {
180 // Large
181 return alloc_large_object(size, flags);
182 }
183 }
184
185 uintptr_t ZObjectAllocator::alloc_object(size_t size) {
186 assert(ZThread::is_java(), "Must be a Java thread");
187
188 ZAllocationFlags flags;
189 flags.set_no_reserve();
190
191 if (!ZStallOnOutOfMemory) {
192 flags.set_non_blocking();
193 }
194
195 return alloc_object(size, flags);
196 }
197
198 uintptr_t ZObjectAllocator::alloc_object_for_relocation(size_t size) {
199 assert(ZThread::is_java() || ZThread::is_worker() || ZThread::is_vm(), "Unknown thread");
200
201 ZAllocationFlags flags;
202 flags.set_relocation();
203 flags.set_non_blocking();
204
205 if (ZThread::is_worker()) {
206 flags.set_worker_thread();
207 }
208
209 return alloc_object(size, flags);
210 }
211
212 bool ZObjectAllocator::undo_alloc_large_object(ZPage* page) {
213 assert(page->type() == ZPageTypeLarge, "Invalid page type");
214
215 // Undo page allocation
216 ZHeap::heap()->undo_alloc_page(page);
217 return true;
218 }
219
220 bool ZObjectAllocator::undo_alloc_medium_object(ZPage* page, uintptr_t addr, size_t size) {
221 assert(page->type() == ZPageTypeMedium, "Invalid page type");
222
223 // Try atomic undo on shared page
224 return page->undo_alloc_object_atomic(addr, size);
225 }
226
227 bool ZObjectAllocator::undo_alloc_small_object_from_nonworker(ZPage* page, uintptr_t addr, size_t size) {
228 assert(page->type() == ZPageTypeSmall, "Invalid page type");
229
230 // Try atomic undo on shared page
231 return page->undo_alloc_object_atomic(addr, size);
232 }
233
234 bool ZObjectAllocator::undo_alloc_small_object_from_worker(ZPage* page, uintptr_t addr, size_t size) {
235 assert(page->type() == ZPageTypeSmall, "Invalid page type");
236 assert(page == _worker_small_page.get(), "Invalid page");
237
238 // Non-atomic undo on worker-local page
239 const bool success = page->undo_alloc_object(addr, size);
240 assert(success, "Should always succeed");
241 return success;
242 }
243
244 bool ZObjectAllocator::undo_alloc_small_object(ZPage* page, uintptr_t addr, size_t size) {
245 if (ZThread::is_worker()) {
246 return undo_alloc_small_object_from_worker(page, addr, size);
247 } else {
248 return undo_alloc_small_object_from_nonworker(page, addr, size);
249 }
250 }
251
252 bool ZObjectAllocator::undo_alloc_object(ZPage* page, uintptr_t addr, size_t size) {
253 const uint8_t type = page->type();
254
255 if (type == ZPageTypeSmall) {
256 return undo_alloc_small_object(page, addr, size);
257 } else if (type == ZPageTypeMedium) {
258 return undo_alloc_medium_object(page, addr, size);
259 } else {
260 return undo_alloc_large_object(page);
261 }
262 }
263
264 void ZObjectAllocator::undo_alloc_object_for_relocation(ZPage* page, uintptr_t addr, size_t size) {
265 if (undo_alloc_object(page, addr, size)) {
266 ZStatInc(ZCounterUndoObjectAllocationSucceeded);
267 } else {
268 ZStatInc(ZCounterUndoObjectAllocationFailed);
269 log_trace(gc)("Failed to undo object allocation: " PTR_FORMAT ", Size: " SIZE_FORMAT ", Thread: " PTR_FORMAT " (%s)",
270 addr, size, ZThread::id(), ZThread::name());
271 }
272 }
273
274 size_t ZObjectAllocator::used() const {
275 size_t total_used = 0;
276
277 ZPerCPUConstIterator<size_t> iter(&_used);
278 for (const size_t* cpu_used; iter.next(&cpu_used);) {
279 total_used += *cpu_used;
280 }
281
282 return total_used;
283 }
284
285 size_t ZObjectAllocator::remaining() const {
286 assert(ZThread::is_java(), "Should be a Java thread");
287
288 ZPage* page = _shared_small_page.get();
289 if (page != NULL) {
290 return page->remaining();
291 }
292
293 return 0;
294 }
295
296 void ZObjectAllocator::retire_tlabs() {
297 ZStatTimer timer(ZSubPhasePauseRetireTLABS);
298 assert(SafepointSynchronize::is_at_safepoint(), "Should be at safepoint");
299
300 // Retire TLABs
301 if (UseTLAB) {
302 ZCollectedHeap* heap = ZCollectedHeap::heap();
303 heap->ensure_parsability(true /* retire_tlabs */);
304 heap->resize_all_tlabs();
305 }
306
307 // Reset used
308 _used.set_all(0);
309
310 // Reset allocation pages
311 _shared_medium_page.set(NULL);
312 _shared_small_page.set_all(NULL);
313 _worker_small_page.set_all(NULL);
314 }
315
316 static void remap_tlab_address(HeapWord** p) {
317 *p = (HeapWord*)ZAddress::good_or_null((uintptr_t)*p);
318 }
319
320 void ZObjectAllocator::remap_tlabs() {
321 ZStatTimer timer(ZSubPhasePauseRemapTLABS);
322 assert(SafepointSynchronize::is_at_safepoint(), "Should be at safepoint");
323
324 if (UseTLAB) {
325 for (JavaThreadIteratorWithHandle iter; JavaThread* thread = iter.next(); ) {
326 thread->tlab().addresses_do(remap_tlab_address);
327 }
328 }
329 }