1 /*
2 * Copyright (c) 2013, 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
26 #include "memory/metaspace.hpp"
27 #include "runtime/atomic.hpp"
28 #include "runtime/os.hpp"
29 #include "runtime/threadCritical.hpp"
30 #include "services/memTracker.hpp"
31 #include "services/virtualMemoryTracker.hpp"
32
33 size_t VirtualMemorySummary::_snapshot[CALC_OBJ_SIZE_IN_TYPE(VirtualMemorySnapshot, size_t)];
34
35 void VirtualMemorySummary::initialize() {
36 assert(sizeof(_snapshot) >= sizeof(VirtualMemorySnapshot), "Sanity Check");
37 // Use placement operator new to initialize static data area.
38 ::new ((void*)_snapshot) VirtualMemorySnapshot();
39 }
40
41 void VirtualMemorySummary::snapshot(VirtualMemorySnapshot* s) {
42 // Snapshot current thread stacks
43 VirtualMemoryTracker::snapshot_thread_stacks();
44 as_snapshot()->copy_to(s);
45 }
46
47 SortedLinkedList<ReservedMemoryRegion, compare_reserved_region_base>* VirtualMemoryTracker::_reserved_regions;
48
49 int compare_committed_region(const CommittedMemoryRegion& r1, const CommittedMemoryRegion& r2) {
50 return r1.compare(r2);
51 }
52
53 int compare_reserved_region_base(const ReservedMemoryRegion& r1, const ReservedMemoryRegion& r2) {
54 return r1.compare(r2);
55 }
56
57 static bool is_mergeable_with(CommittedMemoryRegion* rgn, address addr, size_t size, const NativeCallStack& stack) {
58 return rgn->adjacent_to(addr, size) && rgn->call_stack()->equals(stack);
59 }
60
61 static bool is_same_as(CommittedMemoryRegion* rgn, address addr, size_t size, const NativeCallStack& stack) {
62 // It would have made sense to use rgn->equals(...), but equals returns true for overlapping regions.
63 return rgn->same_region(addr, size) && rgn->call_stack()->equals(stack);
64 }
65
66 static LinkedListNode<CommittedMemoryRegion>* find_preceding_node_from(LinkedListNode<CommittedMemoryRegion>* from, address addr) {
67 LinkedListNode<CommittedMemoryRegion>* preceding = NULL;
68
69 for (LinkedListNode<CommittedMemoryRegion>* node = from; node != NULL; node = node->next()) {
70 CommittedMemoryRegion* rgn = node->data();
71
72 // We searched past the region start.
73 if (rgn->end() > addr) {
74 break;
75 }
76
77 preceding = node;
78 }
79
80 return preceding;
81 }
82
83 static bool try_merge_with(LinkedListNode<CommittedMemoryRegion>* node, address addr, size_t size, const NativeCallStack& stack) {
84 if (node != NULL) {
85 CommittedMemoryRegion* rgn = node->data();
86
87 if (is_mergeable_with(rgn, addr, size, stack)) {
88 rgn->expand_region(addr, size);
89 return true;
90 }
91 }
92
93 return false;
94 }
95
96 static bool try_merge_with(LinkedListNode<CommittedMemoryRegion>* node, LinkedListNode<CommittedMemoryRegion>* other) {
97 if (other == NULL) {
98 return false;
99 }
100
101 CommittedMemoryRegion* rgn = other->data();
102 return try_merge_with(node, rgn->base(), rgn->size(), *rgn->call_stack());
103 }
104
105 bool ReservedMemoryRegion::add_committed_region(address addr, size_t size, const NativeCallStack& stack) {
106 assert(addr != NULL, "Invalid address");
107 assert(size > 0, "Invalid size");
108 assert(contain_region(addr, size), "Not contain this region");
109
110 // Find the region that fully precedes the [addr, addr + size) region.
111 LinkedListNode<CommittedMemoryRegion>* prev = find_preceding_node_from(_committed_regions.head(), addr);
112 LinkedListNode<CommittedMemoryRegion>* next = (prev != NULL ? prev->next() : _committed_regions.head());
113
114 if (next != NULL) {
115 // Ignore request if region already exists.
116 if (is_same_as(next->data(), addr, size, stack)) {
117 return true;
118 }
119
120 // The new region is after prev, and either overlaps with the
121 // next region (and maybe more regions), or overlaps with no region.
122 if (next->data()->overlap_region(addr, size)) {
123 // Remove _all_ overlapping regions, and parts of regions,
124 // in preparation for the addition of this new region.
125 remove_uncommitted_region(addr, size);
126
127 // The remove could have split a region into two and created a
128 // new prev region. Need to reset the prev and next pointers.
129 prev = find_preceding_node_from((prev != NULL ? prev : _committed_regions.head()), addr);
130 next = (prev != NULL ? prev->next() : _committed_regions.head());
131 }
132 }
133
134 // At this point the previous overlapping regions have been
135 // cleared, and the full region is guaranteed to be inserted.
136 VirtualMemorySummary::record_committed_memory(size, flag());
137
138 // Try to merge with prev and possibly next.
139 if (try_merge_with(prev, addr, size, stack)) {
140 if (try_merge_with(prev, next)) {
141 // prev was expanded to contain the new region
142 // and next, need to remove next from the list
143 _committed_regions.remove_after(prev);
144 }
145
146 return true;
147 }
148
149 // Didn't merge with prev, try with next.
150 if (try_merge_with(next, addr, size, stack)) {
151 return true;
152 }
153
154 // Couldn't merge with any regions - create a new region.
155 return add_committed_region(CommittedMemoryRegion(addr, size, stack));
156 }
157
158 bool ReservedMemoryRegion::remove_uncommitted_region(LinkedListNode<CommittedMemoryRegion>* node,
159 address addr, size_t size) {
160 assert(addr != NULL, "Invalid address");
161 assert(size > 0, "Invalid size");
162
163 CommittedMemoryRegion* rgn = node->data();
164 assert(rgn->contain_region(addr, size), "Has to be contained");
165 assert(!rgn->same_region(addr, size), "Can not be the same region");
166
167 if (rgn->base() == addr ||
168 rgn->end() == addr + size) {
169 rgn->exclude_region(addr, size);
170 return true;
171 } else {
172 // split this region
173 address top =rgn->end();
174 // use this region for lower part
175 size_t exclude_size = rgn->end() - addr;
176 rgn->exclude_region(addr, exclude_size);
177
178 // higher part
179 address high_base = addr + size;
180 size_t high_size = top - high_base;
181
182 CommittedMemoryRegion high_rgn(high_base, high_size, *rgn->call_stack());
183 LinkedListNode<CommittedMemoryRegion>* high_node = _committed_regions.add(high_rgn);
184 assert(high_node == NULL || node->next() == high_node, "Should be right after");
185 return (high_node != NULL);
186 }
187
188 return false;
189 }
190
191 bool ReservedMemoryRegion::remove_uncommitted_region(address addr, size_t sz) {
192 assert(addr != NULL, "Invalid address");
193 assert(sz > 0, "Invalid size");
194
195 CommittedMemoryRegion del_rgn(addr, sz, *call_stack());
196 address end = addr + sz;
197
198 LinkedListNode<CommittedMemoryRegion>* head = _committed_regions.head();
199 LinkedListNode<CommittedMemoryRegion>* prev = NULL;
200 CommittedMemoryRegion* crgn;
201
202 while (head != NULL) {
203 crgn = head->data();
204
205 if (crgn->same_region(addr, sz)) {
206 VirtualMemorySummary::record_uncommitted_memory(crgn->size(), flag());
207 _committed_regions.remove_after(prev);
208 return true;
209 }
210
211 // del_rgn contains crgn
212 if (del_rgn.contain_region(crgn->base(), crgn->size())) {
213 VirtualMemorySummary::record_uncommitted_memory(crgn->size(), flag());
214 head = head->next();
215 _committed_regions.remove_after(prev);
216 continue; // don't update head or prev
217 }
218
219 // Found addr in the current crgn. There are 2 subcases:
220 if (crgn->contain_address(addr)) {
221
222 // (1) Found addr+size in current crgn as well. (del_rgn is contained in crgn)
223 if (crgn->contain_address(end - 1)) {
224 VirtualMemorySummary::record_uncommitted_memory(sz, flag());
225 return remove_uncommitted_region(head, addr, sz); // done!
226 } else {
227 // (2) Did not find del_rgn's end in crgn.
228 size_t size = crgn->end() - del_rgn.base();
229 crgn->exclude_region(addr, size);
230 VirtualMemorySummary::record_uncommitted_memory(size, flag());
231 }
232
233 } else if (crgn->contain_address(end - 1)) {
234 // Found del_rgn's end, but not its base addr.
235 size_t size = del_rgn.end() - crgn->base();
236 crgn->exclude_region(crgn->base(), size);
237 VirtualMemorySummary::record_uncommitted_memory(size, flag());
238 return true; // should be done if the list is sorted properly!
239 }
240
241 prev = head;
242 head = head->next();
243 }
244
245 return true;
246 }
247
248 void ReservedMemoryRegion::move_committed_regions(address addr, ReservedMemoryRegion& rgn) {
249 assert(addr != NULL, "Invalid address");
250
251 // split committed regions
252 LinkedListNode<CommittedMemoryRegion>* head =
253 _committed_regions.head();
254 LinkedListNode<CommittedMemoryRegion>* prev = NULL;
255
256 while (head != NULL) {
257 if (head->data()->base() >= addr) {
258 break;
259 }
260 prev = head;
261 head = head->next();
262 }
263
264 if (head != NULL) {
265 if (prev != NULL) {
266 prev->set_next(head->next());
267 } else {
268 _committed_regions.set_head(NULL);
269 }
270 }
271
272 rgn._committed_regions.set_head(head);
273 }
274
275 size_t ReservedMemoryRegion::committed_size() const {
276 size_t committed = 0;
277 LinkedListNode<CommittedMemoryRegion>* head =
278 _committed_regions.head();
279 while (head != NULL) {
280 committed += head->data()->size();
281 head = head->next();
282 }
283 return committed;
284 }
285
286 void ReservedMemoryRegion::set_flag(MEMFLAGS f) {
287 assert((flag() == mtNone || flag() == f), "Overwrite memory type");
288 if (flag() != f) {
289 VirtualMemorySummary::move_reserved_memory(flag(), f, size());
290 VirtualMemorySummary::move_committed_memory(flag(), f, committed_size());
291 _flag = f;
292 }
293 }
294
295 address ReservedMemoryRegion::thread_stack_uncommitted_bottom() const {
296 assert(flag() == mtThreadStack, "Only for thread stack");
297 LinkedListNode<CommittedMemoryRegion>* head = _committed_regions.head();
298 address bottom = base();
299 address top = base() + size();
300 while (head != NULL) {
301 address committed_top = head->data()->base() + head->data()->size();
302 if (committed_top < top) {
303 // committed stack guard pages, skip them
304 bottom = head->data()->base() + head->data()->size();
305 head = head->next();
306 } else {
307 assert(top == committed_top, "Sanity");
308 break;
309 }
310 }
311
312 return bottom;
313 }
314
315 bool VirtualMemoryTracker::initialize(NMT_TrackingLevel level) {
316 if (level >= NMT_summary) {
317 VirtualMemorySummary::initialize();
318 }
319 return true;
320 }
321
322 bool VirtualMemoryTracker::late_initialize(NMT_TrackingLevel level) {
323 if (level >= NMT_summary) {
324 _reserved_regions = new (std::nothrow, ResourceObj::C_HEAP, mtNMT)
325 SortedLinkedList<ReservedMemoryRegion, compare_reserved_region_base>();
326 return (_reserved_regions != NULL);
327 }
328 return true;
329 }
330
331 bool VirtualMemoryTracker::add_reserved_region(address base_addr, size_t size,
332 const NativeCallStack& stack, MEMFLAGS flag) {
333 assert(base_addr != NULL, "Invalid address");
334 assert(size > 0, "Invalid size");
335 assert(_reserved_regions != NULL, "Sanity check");
336 ReservedMemoryRegion rgn(base_addr, size, stack, flag);
337 ReservedMemoryRegion* reserved_rgn = _reserved_regions->find(rgn);
338
339 if (reserved_rgn == NULL) {
340 VirtualMemorySummary::record_reserved_memory(size, flag);
341 return _reserved_regions->add(rgn) != NULL;
342 } else {
343 if (reserved_rgn->same_region(base_addr, size)) {
344 reserved_rgn->set_call_stack(stack);
345 reserved_rgn->set_flag(flag);
346 return true;
347 } else if (reserved_rgn->adjacent_to(base_addr, size)) {
348 VirtualMemorySummary::record_reserved_memory(size, flag);
349 reserved_rgn->expand_region(base_addr, size);
350 reserved_rgn->set_call_stack(stack);
351 return true;
352 } else {
353 // Overlapped reservation.
354 // It can happen when the regions are thread stacks, as JNI
355 // thread does not detach from VM before exits, and leads to
356 // leak JavaThread object
357 if (reserved_rgn->flag() == mtThreadStack) {
358 guarantee(!CheckJNICalls, "Attached JNI thread exited without being detached");
359 // Overwrite with new region
360
361 // Release old region
362 VirtualMemorySummary::record_uncommitted_memory(reserved_rgn->committed_size(), reserved_rgn->flag());
363 VirtualMemorySummary::record_released_memory(reserved_rgn->size(), reserved_rgn->flag());
364
365 // Add new region
366 VirtualMemorySummary::record_reserved_memory(rgn.size(), flag);
367
368 *reserved_rgn = rgn;
369 return true;
370 }
371
372 // CDS mapping region.
373 // CDS reserves the whole region for mapping CDS archive, then maps each section into the region.
374 // NMT reports CDS as a whole.
375 if (reserved_rgn->flag() == mtClassShared) {
376 assert(reserved_rgn->contain_region(base_addr, size), "Reserved CDS region should contain this mapping region");
377 return true;
378 }
379
380 // Mapped CDS string region.
381 // The string region(s) is part of the java heap.
382 if (reserved_rgn->flag() == mtJavaHeap) {
383 assert(reserved_rgn->contain_region(base_addr, size), "Reserved heap region should contain this mapping region");
384 return true;
385 }
386
387 ShouldNotReachHere();
388 return false;
389 }
390 }
391 }
392
393 void VirtualMemoryTracker::set_reserved_region_type(address addr, MEMFLAGS flag) {
394 assert(addr != NULL, "Invalid address");
395 assert(_reserved_regions != NULL, "Sanity check");
396
397 ReservedMemoryRegion rgn(addr, 1);
398 ReservedMemoryRegion* reserved_rgn = _reserved_regions->find(rgn);
399 if (reserved_rgn != NULL) {
400 assert(reserved_rgn->contain_address(addr), "Containment");
401 if (reserved_rgn->flag() != flag) {
402 assert(reserved_rgn->flag() == mtNone, "Overwrite memory type");
403 reserved_rgn->set_flag(flag);
404 }
405 }
406 }
407
408 bool VirtualMemoryTracker::add_committed_region(address addr, size_t size,
409 const NativeCallStack& stack) {
410 assert(addr != NULL, "Invalid address");
411 assert(size > 0, "Invalid size");
412 assert(_reserved_regions != NULL, "Sanity check");
413
414 ReservedMemoryRegion rgn(addr, size);
415 ReservedMemoryRegion* reserved_rgn = _reserved_regions->find(rgn);
416
417 assert(reserved_rgn != NULL, "No reserved region");
418 assert(reserved_rgn->contain_region(addr, size), "Not completely contained");
419 bool result = reserved_rgn->add_committed_region(addr, size, stack);
420 return result;
421 }
422
423 bool VirtualMemoryTracker::remove_uncommitted_region(address addr, size_t size) {
424 assert(addr != NULL, "Invalid address");
425 assert(size > 0, "Invalid size");
426 assert(_reserved_regions != NULL, "Sanity check");
427
428 ReservedMemoryRegion rgn(addr, size);
429 ReservedMemoryRegion* reserved_rgn = _reserved_regions->find(rgn);
430 assert(reserved_rgn != NULL, "No reserved region");
431 assert(reserved_rgn->contain_region(addr, size), "Not completely contained");
432 bool result = reserved_rgn->remove_uncommitted_region(addr, size);
433 return result;
434 }
435
436 bool VirtualMemoryTracker::remove_released_region(address addr, size_t size) {
437 assert(addr != NULL, "Invalid address");
438 assert(size > 0, "Invalid size");
439 assert(_reserved_regions != NULL, "Sanity check");
440
441 ReservedMemoryRegion rgn(addr, size);
442 ReservedMemoryRegion* reserved_rgn = _reserved_regions->find(rgn);
443
444 assert(reserved_rgn != NULL, "No reserved region");
445
446 // uncommit regions within the released region
447 if (!reserved_rgn->remove_uncommitted_region(addr, size)) {
448 return false;
449 }
450
451 if (reserved_rgn->flag() == mtClassShared &&
452 reserved_rgn->contain_region(addr, size) &&
453 !reserved_rgn->same_region(addr, size)) {
454 // This is an unmapped CDS region, which is part of the reserved shared
455 // memory region.
456 // See special handling in VirtualMemoryTracker::add_reserved_region also.
457 return true;
458 }
459
460 VirtualMemorySummary::record_released_memory(size, reserved_rgn->flag());
461
462 if (reserved_rgn->same_region(addr, size)) {
463 return _reserved_regions->remove(rgn);
464 } else {
465 assert(reserved_rgn->contain_region(addr, size), "Not completely contained");
466 if (reserved_rgn->base() == addr ||
467 reserved_rgn->end() == addr + size) {
468 reserved_rgn->exclude_region(addr, size);
469 return true;
470 } else {
471 address top = reserved_rgn->end();
472 address high_base = addr + size;
473 ReservedMemoryRegion high_rgn(high_base, top - high_base,
474 *reserved_rgn->call_stack(), reserved_rgn->flag());
475
476 // use original region for lower region
477 reserved_rgn->exclude_region(addr, top - addr);
478 LinkedListNode<ReservedMemoryRegion>* new_rgn = _reserved_regions->add(high_rgn);
479 if (new_rgn == NULL) {
480 return false;
481 } else {
482 reserved_rgn->move_committed_regions(addr, *new_rgn->data());
483 return true;
484 }
485 }
486 }
487 }
488
489 // Walk all known thread stacks, snapshot their committed ranges.
490 class SnapshotThreadStackWalker : public VirtualMemoryWalker {
491 public:
492 SnapshotThreadStackWalker() {}
493
494 bool do_allocation_site(const ReservedMemoryRegion* rgn) {
495 if (rgn->flag() == mtThreadStack) {
496 address stack_bottom = rgn->thread_stack_uncommitted_bottom();
497 size_t stack_size = rgn->base() + rgn->size() - stack_bottom;
498 size_t committed_size = os::committed_stack_size(stack_bottom, stack_size);
499 if (committed_size > 0) {
500 ReservedMemoryRegion* region = const_cast<ReservedMemoryRegion*>(rgn);
501 NativeCallStack ncs; // empty stack
502
503 // Stack grows downward
504 region->add_committed_region(rgn->base() + rgn->size() - committed_size, committed_size, ncs);
505 }
506 }
507 return true;
508 }
509 };
510
511 void VirtualMemoryTracker::snapshot_thread_stacks() {
512 SnapshotThreadStackWalker walker;
513 walk_virtual_memory(&walker);
514 }
515
516 bool VirtualMemoryTracker::walk_virtual_memory(VirtualMemoryWalker* walker) {
517 assert(_reserved_regions != NULL, "Sanity check");
518 ThreadCritical tc;
519 // Check that the _reserved_regions haven't been deleted.
520 if (_reserved_regions != NULL) {
521 LinkedListNode<ReservedMemoryRegion>* head = _reserved_regions->head();
522 while (head != NULL) {
523 const ReservedMemoryRegion* rgn = head->peek();
524 if (!walker->do_allocation_site(rgn)) {
525 return false;
526 }
527 head = head->next();
528 }
529 }
530 return true;
531 }
532
533 // Transition virtual memory tracking level.
534 bool VirtualMemoryTracker::transition(NMT_TrackingLevel from, NMT_TrackingLevel to) {
535 assert (from != NMT_minimal, "cannot convert from the lowest tracking level to anything");
536 if (to == NMT_minimal) {
537 assert(from == NMT_summary || from == NMT_detail, "Just check");
538 // Clean up virtual memory tracking data structures.
539 ThreadCritical tc;
540 // Check for potential race with other thread calling transition
541 if (_reserved_regions != NULL) {
542 delete _reserved_regions;
543 _reserved_regions = NULL;
544 }
545 }
546
547 return true;
548 }
549
550 // Metaspace Support
551 MetaspaceSnapshot::MetaspaceSnapshot() {
552 for (int index = (int)Metaspace::ClassType; index < (int)Metaspace::MetadataTypeCount; index ++) {
553 Metaspace::MetadataType type = (Metaspace::MetadataType)index;
554 assert_valid_metadata_type(type);
555 _reserved_in_bytes[type] = 0;
556 _committed_in_bytes[type] = 0;
557 _used_in_bytes[type] = 0;
558 _free_in_bytes[type] = 0;
559 }
560 }
561
562 void MetaspaceSnapshot::snapshot(Metaspace::MetadataType type, MetaspaceSnapshot& mss) {
563 assert_valid_metadata_type(type);
564
565 mss._reserved_in_bytes[type] = MetaspaceAux::reserved_bytes(type);
566 mss._committed_in_bytes[type] = MetaspaceAux::committed_bytes(type);
567 mss._used_in_bytes[type] = MetaspaceAux::used_bytes(type);
568
569 size_t free_in_bytes = (MetaspaceAux::capacity_bytes(type) - MetaspaceAux::used_bytes(type))
570 + MetaspaceAux::free_chunks_total_bytes(type)
571 + MetaspaceAux::free_bytes(type);
572 mss._free_in_bytes[type] = free_in_bytes;
573 }
574
575 void MetaspaceSnapshot::snapshot(MetaspaceSnapshot& mss) {
576 snapshot(Metaspace::ClassType, mss);
577 if (Metaspace::using_class_space()) {
578 snapshot(Metaspace::NonClassType, mss);
579 }
580 }