1 /*
2 * Copyright (c) 2006, 2021, 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/parallel/mutableNUMASpace.hpp"
27 #include "gc/shared/collectedHeap.hpp"
28 #include "gc/shared/gc_globals.hpp"
29 #include "gc/shared/spaceDecorator.hpp"
30 #include "gc/shared/workgroup.hpp"
31 #include "memory/allocation.inline.hpp"
32 #include "oops/oop.inline.hpp"
33 #include "oops/typeArrayOop.hpp"
34 #include "runtime/atomic.hpp"
35 #include "runtime/java.hpp"
36 #include "runtime/os.inline.hpp"
37 #include "runtime/thread.inline.hpp"
38 #include "runtime/threadSMR.hpp"
39 #include "utilities/align.hpp"
40
41 MutableNUMASpace::MutableNUMASpace(size_t alignment) : MutableSpace(alignment), _must_use_large_pages(false) {
42 _lgrp_spaces = new (ResourceObj::C_HEAP, mtGC) GrowableArray<LGRPSpace*>(0, mtGC);
43 _page_size = os::vm_page_size();
44 _adaptation_cycles = 0;
45 _samples_count = 0;
46
47 #ifdef LINUX
48 // Changing the page size can lead to freeing of memory. When using large pages
49 // and the memory has been both reserved and committed, Linux does not support
50 // freeing parts of it.
51 if (UseLargePages && !os::can_commit_large_page_memory()) {
52 _must_use_large_pages = true;
53 }
54 #endif // LINUX
55
56 update_layout(true);
57 }
58
59 MutableNUMASpace::~MutableNUMASpace() {
60 for (int i = 0; i < lgrp_spaces()->length(); i++) {
61 delete lgrp_spaces()->at(i);
62 }
63 delete lgrp_spaces();
64 }
65
66 #ifndef PRODUCT
67 void MutableNUMASpace::mangle_unused_area() {
68 // This method should do nothing.
69 // It can be called on a numa space during a full compaction.
70 }
71 void MutableNUMASpace::mangle_unused_area_complete() {
72 // This method should do nothing.
73 // It can be called on a numa space during a full compaction.
74 }
75 void MutableNUMASpace::mangle_region(MemRegion mr) {
76 // This method should do nothing because numa spaces are not mangled.
77 }
78 void MutableNUMASpace::set_top_for_allocations(HeapWord* v) {
79 assert(false, "Do not mangle MutableNUMASpace's");
80 }
81 void MutableNUMASpace::set_top_for_allocations() {
82 // This method should do nothing.
83 }
84 void MutableNUMASpace::check_mangled_unused_area(HeapWord* limit) {
85 // This method should do nothing.
86 }
87 void MutableNUMASpace::check_mangled_unused_area_complete() {
88 // This method should do nothing.
89 }
90 #endif // NOT_PRODUCT
91
92 // There may be unallocated holes in the middle chunks
93 // that should be filled with dead objects to ensure parsability.
94 void MutableNUMASpace::ensure_parsability() {
95 for (int i = 0; i < lgrp_spaces()->length(); i++) {
96 LGRPSpace *ls = lgrp_spaces()->at(i);
97 MutableSpace *s = ls->space();
98 if (s->top() < top()) { // For all spaces preceding the one containing top()
99 if (s->free_in_words() > 0) {
100 HeapWord* cur_top = s->top();
101 size_t words_left_to_fill = pointer_delta(s->end(), s->top());;
102 while (words_left_to_fill > 0) {
103 size_t words_to_fill = MIN2(words_left_to_fill, CollectedHeap::filler_array_max_size());
104 assert(words_to_fill >= CollectedHeap::min_fill_size(),
105 "Remaining size (" SIZE_FORMAT ") is too small to fill (based on " SIZE_FORMAT " and " SIZE_FORMAT ")",
106 words_to_fill, words_left_to_fill, CollectedHeap::filler_array_max_size());
107 CollectedHeap::fill_with_object(cur_top, words_to_fill);
108 if (!os::numa_has_static_binding()) {
109 size_t touched_words = words_to_fill;
110 #ifndef ASSERT
111 if (!ZapUnusedHeapArea) {
112 touched_words = MIN2((size_t)align_object_size(typeArrayOopDesc::header_size(T_INT)),
113 touched_words);
114 }
115 #endif
116 MemRegion invalid;
117 HeapWord *crossing_start = align_up(cur_top, os::vm_page_size());
118 HeapWord *crossing_end = align_down(cur_top + touched_words, os::vm_page_size());
119 if (crossing_start != crossing_end) {
120 // If object header crossed a small page boundary we mark the area
121 // as invalid rounding it to a page_size().
122 HeapWord *start = MAX2(align_down(cur_top, page_size()), s->bottom());
123 HeapWord *end = MIN2(align_up(cur_top + touched_words, page_size()), s->end());
124 invalid = MemRegion(start, end);
125 }
126
127 ls->add_invalid_region(invalid);
128 }
129 cur_top += words_to_fill;
130 words_left_to_fill -= words_to_fill;
131 }
132 }
133 } else {
134 if (!os::numa_has_static_binding()) {
135 #ifdef ASSERT
136 MemRegion invalid(s->top(), s->end());
137 ls->add_invalid_region(invalid);
138 #else
139 if (ZapUnusedHeapArea) {
140 MemRegion invalid(s->top(), s->end());
141 ls->add_invalid_region(invalid);
142 } else {
143 return;
144 }
145 #endif
146 } else {
147 return;
148 }
149 }
150 }
151 }
152
153 size_t MutableNUMASpace::used_in_words() const {
154 size_t s = 0;
155 for (int i = 0; i < lgrp_spaces()->length(); i++) {
156 s += lgrp_spaces()->at(i)->space()->used_in_words();
157 }
158 return s;
159 }
160
161 size_t MutableNUMASpace::free_in_words() const {
162 size_t s = 0;
163 for (int i = 0; i < lgrp_spaces()->length(); i++) {
164 s += lgrp_spaces()->at(i)->space()->free_in_words();
165 }
166 return s;
167 }
168
169
170 size_t MutableNUMASpace::tlab_capacity(Thread *thr) const {
171 guarantee(thr != NULL, "No thread");
172 int lgrp_id = thr->lgrp_id();
173 if (lgrp_id == -1) {
174 // This case can occur after the topology of the system has
175 // changed. Thread can change their location, the new home
176 // group will be determined during the first allocation
177 // attempt. For now we can safely assume that all spaces
178 // have equal size because the whole space will be reinitialized.
179 if (lgrp_spaces()->length() > 0) {
180 return capacity_in_bytes() / lgrp_spaces()->length();
181 } else {
182 assert(false, "There should be at least one locality group");
183 return 0;
184 }
185 }
186 // That's the normal case, where we know the locality group of the thread.
187 int i = lgrp_spaces()->find(&lgrp_id, LGRPSpace::equals);
188 if (i == -1) {
189 return 0;
190 }
191 return lgrp_spaces()->at(i)->space()->capacity_in_bytes();
192 }
193
194 size_t MutableNUMASpace::tlab_used(Thread *thr) const {
195 // Please see the comments for tlab_capacity().
196 guarantee(thr != NULL, "No thread");
197 int lgrp_id = thr->lgrp_id();
198 if (lgrp_id == -1) {
199 if (lgrp_spaces()->length() > 0) {
200 return (used_in_bytes()) / lgrp_spaces()->length();
201 } else {
202 assert(false, "There should be at least one locality group");
203 return 0;
204 }
205 }
206 int i = lgrp_spaces()->find(&lgrp_id, LGRPSpace::equals);
207 if (i == -1) {
208 return 0;
209 }
210 return lgrp_spaces()->at(i)->space()->used_in_bytes();
211 }
212
213
214 size_t MutableNUMASpace::unsafe_max_tlab_alloc(Thread *thr) const {
215 // Please see the comments for tlab_capacity().
216 guarantee(thr != NULL, "No thread");
217 int lgrp_id = thr->lgrp_id();
218 if (lgrp_id == -1) {
219 if (lgrp_spaces()->length() > 0) {
220 return free_in_bytes() / lgrp_spaces()->length();
221 } else {
222 assert(false, "There should be at least one locality group");
223 return 0;
224 }
225 }
226 int i = lgrp_spaces()->find(&lgrp_id, LGRPSpace::equals);
227 if (i == -1) {
228 return 0;
229 }
230 return lgrp_spaces()->at(i)->space()->free_in_bytes();
231 }
232
233
234 size_t MutableNUMASpace::capacity_in_words(Thread* thr) const {
235 guarantee(thr != NULL, "No thread");
236 int lgrp_id = thr->lgrp_id();
237 if (lgrp_id == -1) {
238 if (lgrp_spaces()->length() > 0) {
239 return capacity_in_words() / lgrp_spaces()->length();
240 } else {
241 assert(false, "There should be at least one locality group");
242 return 0;
243 }
244 }
245 int i = lgrp_spaces()->find(&lgrp_id, LGRPSpace::equals);
246 if (i == -1) {
247 return 0;
248 }
249 return lgrp_spaces()->at(i)->space()->capacity_in_words();
250 }
251
252 // Check if the NUMA topology has changed. Add and remove spaces if needed.
253 // The update can be forced by setting the force parameter equal to true.
254 bool MutableNUMASpace::update_layout(bool force) {
255 // Check if the topology had changed.
256 bool changed = os::numa_topology_changed();
257 if (force || changed) {
258 // Compute lgrp intersection. Add/remove spaces.
259 int lgrp_limit = (int)os::numa_get_groups_num();
260 int *lgrp_ids = NEW_C_HEAP_ARRAY(int, lgrp_limit, mtGC);
261 int lgrp_num = (int)os::numa_get_leaf_groups(lgrp_ids, lgrp_limit);
262 assert(lgrp_num > 0, "There should be at least one locality group");
263 // Add new spaces for the new nodes
264 for (int i = 0; i < lgrp_num; i++) {
265 bool found = false;
266 for (int j = 0; j < lgrp_spaces()->length(); j++) {
267 if (lgrp_spaces()->at(j)->lgrp_id() == lgrp_ids[i]) {
268 found = true;
269 break;
270 }
271 }
272 if (!found) {
273 lgrp_spaces()->append(new LGRPSpace(lgrp_ids[i], alignment()));
274 }
275 }
276
277 // Remove spaces for the removed nodes.
278 for (int i = 0; i < lgrp_spaces()->length();) {
279 bool found = false;
280 for (int j = 0; j < lgrp_num; j++) {
281 if (lgrp_spaces()->at(i)->lgrp_id() == lgrp_ids[j]) {
282 found = true;
283 break;
284 }
285 }
286 if (!found) {
287 delete lgrp_spaces()->at(i);
288 lgrp_spaces()->remove_at(i);
289 } else {
290 i++;
291 }
292 }
293
294 FREE_C_HEAP_ARRAY(int, lgrp_ids);
295
296 if (changed) {
297 for (JavaThreadIteratorWithHandle jtiwh; JavaThread *thread = jtiwh.next(); ) {
298 thread->set_lgrp_id(-1);
299 }
300 }
301 return true;
302 }
303 return false;
304 }
305
306 // Bias region towards the first-touching lgrp. Set the right page sizes.
307 void MutableNUMASpace::bias_region(MemRegion mr, int lgrp_id) {
308 HeapWord *start = align_up(mr.start(), page_size());
309 HeapWord *end = align_down(mr.end(), page_size());
310 if (end > start) {
311 MemRegion aligned_region(start, end);
312 assert((intptr_t)aligned_region.start() % page_size() == 0 &&
313 (intptr_t)aligned_region.byte_size() % page_size() == 0, "Bad alignment");
314 assert(region().contains(aligned_region), "Sanity");
315 // First we tell the OS which page size we want in the given range. The underlying
316 // large page can be broken down if we require small pages.
317 os::realign_memory((char*)aligned_region.start(), aligned_region.byte_size(), page_size());
318 // Then we uncommit the pages in the range.
319 os::free_memory((char*)aligned_region.start(), aligned_region.byte_size(), page_size());
320 // And make them local/first-touch biased.
321 os::numa_make_local((char*)aligned_region.start(), aligned_region.byte_size(), lgrp_id);
322 }
323 }
324
325 // Free all pages in the region.
326 void MutableNUMASpace::free_region(MemRegion mr) {
327 HeapWord *start = align_up(mr.start(), page_size());
328 HeapWord *end = align_down(mr.end(), page_size());
329 if (end > start) {
330 MemRegion aligned_region(start, end);
331 assert((intptr_t)aligned_region.start() % page_size() == 0 &&
332 (intptr_t)aligned_region.byte_size() % page_size() == 0, "Bad alignment");
333 assert(region().contains(aligned_region), "Sanity");
334 os::free_memory((char*)aligned_region.start(), aligned_region.byte_size(), page_size());
335 }
336 }
337
338 // Update space layout. Perform adaptation.
339 void MutableNUMASpace::update() {
340 if (update_layout(false)) {
341 // If the topology has changed, make all chunks zero-sized.
342 // And clear the alloc-rate statistics.
343 // In future we may want to handle this more gracefully in order
344 // to avoid the reallocation of the pages as much as possible.
345 for (int i = 0; i < lgrp_spaces()->length(); i++) {
346 LGRPSpace *ls = lgrp_spaces()->at(i);
347 MutableSpace *s = ls->space();
348 s->set_end(s->bottom());
349 s->set_top(s->bottom());
350 ls->clear_alloc_rate();
351 }
352 // A NUMA space is never mangled
353 initialize(region(),
354 SpaceDecorator::Clear,
355 SpaceDecorator::DontMangle);
356 } else {
357 bool should_initialize = false;
358 if (!os::numa_has_static_binding()) {
359 for (int i = 0; i < lgrp_spaces()->length(); i++) {
360 if (!lgrp_spaces()->at(i)->invalid_region().is_empty()) {
361 should_initialize = true;
362 break;
363 }
364 }
365 }
366
367 if (should_initialize ||
368 (UseAdaptiveNUMAChunkSizing && adaptation_cycles() < samples_count())) {
369 // A NUMA space is never mangled
370 initialize(region(),
371 SpaceDecorator::Clear,
372 SpaceDecorator::DontMangle);
373 }
374 }
375
376 if (NUMAStats) {
377 for (int i = 0; i < lgrp_spaces()->length(); i++) {
378 lgrp_spaces()->at(i)->accumulate_statistics(page_size());
379 }
380 }
381
382 scan_pages(NUMAPageScanRate);
383 }
384
385 // Scan pages. Free pages that have smaller size or wrong placement.
386 void MutableNUMASpace::scan_pages(size_t page_count)
387 {
388 size_t pages_per_chunk = page_count / lgrp_spaces()->length();
389 if (pages_per_chunk > 0) {
390 for (int i = 0; i < lgrp_spaces()->length(); i++) {
391 LGRPSpace *ls = lgrp_spaces()->at(i);
392 ls->scan_pages(page_size(), pages_per_chunk);
393 }
394 }
395 }
396
397 // Accumulate statistics about the allocation rate of each lgrp.
398 void MutableNUMASpace::accumulate_statistics() {
399 if (UseAdaptiveNUMAChunkSizing) {
400 for (int i = 0; i < lgrp_spaces()->length(); i++) {
401 lgrp_spaces()->at(i)->sample();
402 }
403 increment_samples_count();
404 }
405
406 if (NUMAStats) {
407 for (int i = 0; i < lgrp_spaces()->length(); i++) {
408 lgrp_spaces()->at(i)->accumulate_statistics(page_size());
409 }
410 }
411 }
412
413 // Get the current size of a chunk.
414 // This function computes the size of the chunk based on the
415 // difference between chunk ends. This allows it to work correctly in
416 // case the whole space is resized and during the process of adaptive
417 // chunk resizing.
418 size_t MutableNUMASpace::current_chunk_size(int i) {
419 HeapWord *cur_end, *prev_end;
420 if (i == 0) {
421 prev_end = bottom();
422 } else {
423 prev_end = lgrp_spaces()->at(i - 1)->space()->end();
424 }
425 if (i == lgrp_spaces()->length() - 1) {
426 cur_end = end();
427 } else {
428 cur_end = lgrp_spaces()->at(i)->space()->end();
429 }
430 if (cur_end > prev_end) {
431 return pointer_delta(cur_end, prev_end, sizeof(char));
432 }
433 return 0;
434 }
435
436 // Return the default chunk size by equally diving the space.
437 // page_size() aligned.
438 size_t MutableNUMASpace::default_chunk_size() {
439 return base_space_size() / lgrp_spaces()->length() * page_size();
440 }
441
442 // Produce a new chunk size. page_size() aligned.
443 // This function is expected to be called on sequence of i's from 0 to
444 // lgrp_spaces()->length().
445 size_t MutableNUMASpace::adaptive_chunk_size(int i, size_t limit) {
446 size_t pages_available = base_space_size();
447 for (int j = 0; j < i; j++) {
448 pages_available -= align_down(current_chunk_size(j), page_size()) / page_size();
449 }
450 pages_available -= lgrp_spaces()->length() - i - 1;
451 assert(pages_available > 0, "No pages left");
452 float alloc_rate = 0;
453 for (int j = i; j < lgrp_spaces()->length(); j++) {
454 alloc_rate += lgrp_spaces()->at(j)->alloc_rate()->average();
455 }
456 size_t chunk_size = 0;
457 if (alloc_rate > 0) {
458 LGRPSpace *ls = lgrp_spaces()->at(i);
459 chunk_size = (size_t)(ls->alloc_rate()->average() / alloc_rate * pages_available) * page_size();
460 }
461 chunk_size = MAX2(chunk_size, page_size());
462
463 if (limit > 0) {
464 limit = align_down(limit, page_size());
465 if (chunk_size > current_chunk_size(i)) {
466 size_t upper_bound = pages_available * page_size();
467 if (upper_bound > limit &&
468 current_chunk_size(i) < upper_bound - limit) {
469 // The resulting upper bound should not exceed the available
470 // amount of memory (pages_available * page_size()).
471 upper_bound = current_chunk_size(i) + limit;
472 }
473 chunk_size = MIN2(chunk_size, upper_bound);
474 } else {
475 size_t lower_bound = page_size();
476 if (current_chunk_size(i) > limit) { // lower_bound shouldn't underflow.
477 lower_bound = current_chunk_size(i) - limit;
478 }
479 chunk_size = MAX2(chunk_size, lower_bound);
480 }
481 }
482 assert(chunk_size <= pages_available * page_size(), "Chunk size out of range");
483 return chunk_size;
484 }
485
486
487 // Return the bottom_region and the top_region. Align them to page_size() boundary.
488 // |------------------new_region---------------------------------|
489 // |----bottom_region--|---intersection---|------top_region------|
490 void MutableNUMASpace::select_tails(MemRegion new_region, MemRegion intersection,
491 MemRegion* bottom_region, MemRegion *top_region) {
492 // Is there bottom?
493 if (new_region.start() < intersection.start()) { // Yes
494 // Try to coalesce small pages into a large one.
495 if (UseLargePages && page_size() >= alignment()) {
496 HeapWord* p = align_up(intersection.start(), alignment());
497 if (new_region.contains(p)
498 && pointer_delta(p, new_region.start(), sizeof(char)) >= alignment()) {
499 if (intersection.contains(p)) {
500 intersection = MemRegion(p, intersection.end());
501 } else {
502 intersection = MemRegion(p, p);
503 }
504 }
505 }
506 *bottom_region = MemRegion(new_region.start(), intersection.start());
507 } else {
508 *bottom_region = MemRegion();
509 }
510
511 // Is there top?
512 if (intersection.end() < new_region.end()) { // Yes
513 // Try to coalesce small pages into a large one.
514 if (UseLargePages && page_size() >= alignment()) {
515 HeapWord* p = align_down(intersection.end(), alignment());
516 if (new_region.contains(p)
517 && pointer_delta(new_region.end(), p, sizeof(char)) >= alignment()) {
518 if (intersection.contains(p)) {
519 intersection = MemRegion(intersection.start(), p);
520 } else {
521 intersection = MemRegion(p, p);
522 }
523 }
524 }
525 *top_region = MemRegion(intersection.end(), new_region.end());
526 } else {
527 *top_region = MemRegion();
528 }
529 }
530
531 // Try to merge the invalid region with the bottom or top region by decreasing
532 // the intersection area. Return the invalid_region aligned to the page_size()
533 // boundary if it's inside the intersection. Return non-empty invalid_region
534 // if it lies inside the intersection (also page-aligned).
535 // |------------------new_region---------------------------------|
536 // |----------------|-------invalid---|--------------------------|
537 // |----bottom_region--|---intersection---|------top_region------|
538 void MutableNUMASpace::merge_regions(MemRegion new_region, MemRegion* intersection,
539 MemRegion *invalid_region) {
540 if (intersection->start() >= invalid_region->start() && intersection->contains(invalid_region->end())) {
541 *intersection = MemRegion(invalid_region->end(), intersection->end());
542 *invalid_region = MemRegion();
543 } else
544 if (intersection->end() <= invalid_region->end() && intersection->contains(invalid_region->start())) {
545 *intersection = MemRegion(intersection->start(), invalid_region->start());
546 *invalid_region = MemRegion();
547 } else
548 if (intersection->equals(*invalid_region) || invalid_region->contains(*intersection)) {
549 *intersection = MemRegion(new_region.start(), new_region.start());
550 *invalid_region = MemRegion();
551 } else
552 if (intersection->contains(invalid_region)) {
553 // That's the only case we have to make an additional bias_region() call.
554 HeapWord* start = invalid_region->start();
555 HeapWord* end = invalid_region->end();
556 if (UseLargePages && page_size() >= alignment()) {
557 HeapWord *p = align_down(start, alignment());
558 if (new_region.contains(p)) {
559 start = p;
560 }
561 p = align_up(end, alignment());
562 if (new_region.contains(end)) {
563 end = p;
564 }
565 }
566 if (intersection->start() > start) {
567 *intersection = MemRegion(start, intersection->end());
568 }
569 if (intersection->end() < end) {
570 *intersection = MemRegion(intersection->start(), end);
571 }
572 *invalid_region = MemRegion(start, end);
573 }
574 }
575
576 void MutableNUMASpace::initialize(MemRegion mr,
577 bool clear_space,
578 bool mangle_space,
579 bool setup_pages,
580 WorkGang* pretouch_gang) {
581 assert(clear_space, "Reallocation will destroy data!");
582 assert(lgrp_spaces()->length() > 0, "There should be at least one space");
583
584 MemRegion old_region = region(), new_region;
585 set_bottom(mr.start());
586 set_end(mr.end());
587 // Must always clear the space
588 clear(SpaceDecorator::DontMangle);
589
590 // Compute chunk sizes
591 size_t prev_page_size = page_size();
592 set_page_size(UseLargePages ? alignment() : os::vm_page_size());
593 HeapWord* rounded_bottom = align_up(bottom(), page_size());
594 HeapWord* rounded_end = align_down(end(), page_size());
595 size_t base_space_size_pages = pointer_delta(rounded_end, rounded_bottom, sizeof(char)) / page_size();
596
597 // Try small pages if the chunk size is too small
598 if (base_space_size_pages / lgrp_spaces()->length() == 0
599 && page_size() > (size_t)os::vm_page_size()) {
600 // Changing the page size below can lead to freeing of memory. So we fail initialization.
601 if (_must_use_large_pages) {
602 vm_exit_during_initialization("Failed initializing NUMA with large pages. Too small heap size");
603 }
604 set_page_size(os::vm_page_size());
605 rounded_bottom = align_up(bottom(), page_size());
606 rounded_end = align_down(end(), page_size());
607 base_space_size_pages = pointer_delta(rounded_end, rounded_bottom, sizeof(char)) / page_size();
608 }
609 guarantee(base_space_size_pages / lgrp_spaces()->length() > 0, "Space too small");
610 set_base_space_size(base_space_size_pages);
611
612 // Handle space resize
613 MemRegion top_region, bottom_region;
614 if (!old_region.equals(region())) {
615 new_region = MemRegion(rounded_bottom, rounded_end);
616 MemRegion intersection = new_region.intersection(old_region);
617 if (intersection.start() == NULL ||
618 intersection.end() == NULL ||
619 prev_page_size > page_size()) { // If the page size got smaller we have to change
620 // the page size preference for the whole space.
621 intersection = MemRegion(new_region.start(), new_region.start());
622 }
623 select_tails(new_region, intersection, &bottom_region, &top_region);
624 bias_region(bottom_region, lgrp_spaces()->at(0)->lgrp_id());
625 bias_region(top_region, lgrp_spaces()->at(lgrp_spaces()->length() - 1)->lgrp_id());
626 }
627
628 // Check if the space layout has changed significantly?
629 // This happens when the space has been resized so that either head or tail
630 // chunk became less than a page.
631 bool layout_valid = UseAdaptiveNUMAChunkSizing &&
632 current_chunk_size(0) > page_size() &&
633 current_chunk_size(lgrp_spaces()->length() - 1) > page_size();
634
635
636 for (int i = 0; i < lgrp_spaces()->length(); i++) {
637 LGRPSpace *ls = lgrp_spaces()->at(i);
638 MutableSpace *s = ls->space();
639 old_region = s->region();
640
641 size_t chunk_byte_size = 0, old_chunk_byte_size = 0;
642 if (i < lgrp_spaces()->length() - 1) {
643 if (!UseAdaptiveNUMAChunkSizing ||
644 (UseAdaptiveNUMAChunkSizing && NUMAChunkResizeWeight == 0) ||
645 samples_count() < AdaptiveSizePolicyReadyThreshold) {
646 // No adaptation. Divide the space equally.
647 chunk_byte_size = default_chunk_size();
648 } else
649 if (!layout_valid || NUMASpaceResizeRate == 0) {
650 // Fast adaptation. If no space resize rate is set, resize
651 // the chunks instantly.
652 chunk_byte_size = adaptive_chunk_size(i, 0);
653 } else {
654 // Slow adaptation. Resize the chunks moving no more than
655 // NUMASpaceResizeRate bytes per collection.
656 size_t limit = NUMASpaceResizeRate /
657 (lgrp_spaces()->length() * (lgrp_spaces()->length() + 1) / 2);
658 chunk_byte_size = adaptive_chunk_size(i, MAX2(limit * (i + 1), page_size()));
659 }
660
661 assert(chunk_byte_size >= page_size(), "Chunk size too small");
662 assert(chunk_byte_size <= capacity_in_bytes(), "Sanity check");
663 }
664
665 if (i == 0) { // Bottom chunk
666 if (i != lgrp_spaces()->length() - 1) {
667 new_region = MemRegion(bottom(), rounded_bottom + (chunk_byte_size >> LogHeapWordSize));
668 } else {
669 new_region = MemRegion(bottom(), end());
670 }
671 } else
672 if (i < lgrp_spaces()->length() - 1) { // Middle chunks
673 MutableSpace *ps = lgrp_spaces()->at(i - 1)->space();
674 new_region = MemRegion(ps->end(),
675 ps->end() + (chunk_byte_size >> LogHeapWordSize));
676 } else { // Top chunk
677 MutableSpace *ps = lgrp_spaces()->at(i - 1)->space();
678 new_region = MemRegion(ps->end(), end());
679 }
680 guarantee(region().contains(new_region), "Region invariant");
681
682
683 // The general case:
684 // |---------------------|--invalid---|--------------------------|
685 // |------------------new_region---------------------------------|
686 // |----bottom_region--|---intersection---|------top_region------|
687 // |----old_region----|
688 // The intersection part has all pages in place we don't need to migrate them.
689 // Pages for the top and bottom part should be freed and then reallocated.
690
691 MemRegion intersection = old_region.intersection(new_region);
692
693 if (intersection.start() == NULL || intersection.end() == NULL) {
694 intersection = MemRegion(new_region.start(), new_region.start());
695 }
696
697 if (!os::numa_has_static_binding()) {
698 MemRegion invalid_region = ls->invalid_region().intersection(new_region);
699 // Invalid region is a range of memory that could've possibly
700 // been allocated on the other node. That's relevant only on Solaris where
701 // there is no static memory binding.
702 if (!invalid_region.is_empty()) {
703 merge_regions(new_region, &intersection, &invalid_region);
704 free_region(invalid_region);
705 ls->set_invalid_region(MemRegion());
706 }
707 }
708
709 select_tails(new_region, intersection, &bottom_region, &top_region);
710
711 if (!os::numa_has_static_binding()) {
712 // If that's a system with the first-touch policy then it's enough
713 // to free the pages.
714 free_region(bottom_region);
715 free_region(top_region);
716 } else {
717 // In a system with static binding we have to change the bias whenever
718 // we reshape the heap.
719 bias_region(bottom_region, ls->lgrp_id());
720 bias_region(top_region, ls->lgrp_id());
721 }
722
723 // Clear space (set top = bottom) but never mangle.
724 s->initialize(new_region, SpaceDecorator::Clear, SpaceDecorator::DontMangle, MutableSpace::DontSetupPages);
725
726 set_adaptation_cycles(samples_count());
727 }
728 }
729
730 // Set the top of the whole space.
731 // Mark the the holes in chunks below the top() as invalid.
732 void MutableNUMASpace::set_top(HeapWord* value) {
733 bool found_top = false;
734 for (int i = 0; i < lgrp_spaces()->length();) {
735 LGRPSpace *ls = lgrp_spaces()->at(i);
736 MutableSpace *s = ls->space();
737 HeapWord *top = MAX2(align_down(s->top(), page_size()), s->bottom());
738
739 if (s->contains(value)) {
740 // Check if setting the chunk's top to a given value would create a hole less than
741 // a minimal object; assuming that's not the last chunk in which case we don't care.
742 if (i < lgrp_spaces()->length() - 1) {
743 size_t remainder = pointer_delta(s->end(), value);
744 const size_t min_fill_size = CollectedHeap::min_fill_size();
745 if (remainder < min_fill_size && remainder > 0) {
746 // Add a minimum size filler object; it will cross the chunk boundary.
747 CollectedHeap::fill_with_object(value, min_fill_size);
748 value += min_fill_size;
749 assert(!s->contains(value), "Should be in the next chunk");
750 // Restart the loop from the same chunk, since the value has moved
751 // to the next one.
752 continue;
753 }
754 }
755
756 if (!os::numa_has_static_binding() && top < value && top < s->end()) {
757 ls->add_invalid_region(MemRegion(top, value));
758 }
759 s->set_top(value);
760 found_top = true;
761 } else {
762 if (found_top) {
763 s->set_top(s->bottom());
764 } else {
765 if (!os::numa_has_static_binding() && top < s->end()) {
766 ls->add_invalid_region(MemRegion(top, s->end()));
767 }
768 s->set_top(s->end());
769 }
770 }
771 i++;
772 }
773 MutableSpace::set_top(value);
774 }
775
776 void MutableNUMASpace::clear(bool mangle_space) {
777 MutableSpace::set_top(bottom());
778 for (int i = 0; i < lgrp_spaces()->length(); i++) {
779 // Never mangle NUMA spaces because the mangling will
780 // bind the memory to a possibly unwanted lgroup.
781 lgrp_spaces()->at(i)->space()->clear(SpaceDecorator::DontMangle);
782 }
783 }
784
785 /*
786 Linux supports static memory binding, therefore the most part of the
787 logic dealing with the possible invalid page allocation is effectively
788 disabled. Besides there is no notion of the home node in Linux. A
789 thread is allowed to migrate freely. Although the scheduler is rather
790 reluctant to move threads between the nodes. We check for the current
791 node every allocation. And with a high probability a thread stays on
792 the same node for some time allowing local access to recently allocated
793 objects.
794 */
795
796 HeapWord* MutableNUMASpace::cas_allocate(size_t size) {
797 Thread* thr = Thread::current();
798 int lgrp_id = thr->lgrp_id();
799 if (lgrp_id == -1 || !os::numa_has_group_homing()) {
800 lgrp_id = os::numa_get_group_id();
801 thr->set_lgrp_id(lgrp_id);
802 }
803
804 int i = lgrp_spaces()->find(&lgrp_id, LGRPSpace::equals);
805 // It is possible that a new CPU has been hotplugged and
806 // we haven't reshaped the space accordingly.
807 if (i == -1) {
808 i = os::random() % lgrp_spaces()->length();
809 }
810 LGRPSpace *ls = lgrp_spaces()->at(i);
811 MutableSpace *s = ls->space();
812 HeapWord *p = s->cas_allocate(size);
813 if (p != NULL) {
814 size_t remainder = pointer_delta(s->end(), p + size);
815 if (remainder < CollectedHeap::min_fill_size() && remainder > 0) {
816 if (s->cas_deallocate(p, size)) {
817 // We were the last to allocate and created a fragment less than
818 // a minimal object.
819 p = NULL;
820 } else {
821 guarantee(false, "Deallocation should always succeed");
822 }
823 }
824 }
825 if (p != NULL) {
826 HeapWord* cur_top, *cur_chunk_top = p + size;
827 while ((cur_top = top()) < cur_chunk_top) { // Keep _top updated.
828 if (Atomic::cmpxchg(top_addr(), cur_top, cur_chunk_top) == cur_top) {
829 break;
830 }
831 }
832 }
833
834 // Make the page allocation happen here if there is no static binding.
835 if (p != NULL && !os::numa_has_static_binding() ) {
836 for (HeapWord *i = p; i < p + size; i += os::vm_page_size() >> LogHeapWordSize) {
837 *(int*)i = 0;
838 }
839 }
840 if (p == NULL) {
841 ls->set_allocation_failed();
842 }
843 return p;
844 }
845
846 void MutableNUMASpace::print_short_on(outputStream* st) const {
847 MutableSpace::print_short_on(st);
848 st->print(" (");
849 for (int i = 0; i < lgrp_spaces()->length(); i++) {
850 st->print("lgrp %d: ", lgrp_spaces()->at(i)->lgrp_id());
851 lgrp_spaces()->at(i)->space()->print_short_on(st);
852 if (i < lgrp_spaces()->length() - 1) {
853 st->print(", ");
854 }
855 }
856 st->print(")");
857 }
858
859 void MutableNUMASpace::print_on(outputStream* st) const {
860 MutableSpace::print_on(st);
861 for (int i = 0; i < lgrp_spaces()->length(); i++) {
862 LGRPSpace *ls = lgrp_spaces()->at(i);
863 st->print(" lgrp %d", ls->lgrp_id());
864 ls->space()->print_on(st);
865 if (NUMAStats) {
866 for (int i = 0; i < lgrp_spaces()->length(); i++) {
867 lgrp_spaces()->at(i)->accumulate_statistics(page_size());
868 }
869 st->print(" local/remote/unbiased/uncommitted: " SIZE_FORMAT "K/"
870 SIZE_FORMAT "K/" SIZE_FORMAT "K/" SIZE_FORMAT
871 "K, large/small pages: " SIZE_FORMAT "/" SIZE_FORMAT "\n",
872 ls->space_stats()->_local_space / K,
873 ls->space_stats()->_remote_space / K,
874 ls->space_stats()->_unbiased_space / K,
875 ls->space_stats()->_uncommited_space / K,
876 ls->space_stats()->_large_pages,
877 ls->space_stats()->_small_pages);
878 }
879 }
880 }
881
882 void MutableNUMASpace::verify() {
883 // This can be called after setting an arbitrary value to the space's top,
884 // so an object can cross the chunk boundary. We ensure the parsability
885 // of the space and just walk the objects in linear fashion.
886 ensure_parsability();
887 MutableSpace::verify();
888 }
889
890 // Scan pages and gather stats about page placement and size.
891 void MutableNUMASpace::LGRPSpace::accumulate_statistics(size_t page_size) {
892 clear_space_stats();
893 char *start = (char*)align_up(space()->bottom(), page_size);
894 char* end = (char*)align_down(space()->end(), page_size);
895 if (start < end) {
896 for (char *p = start; p < end;) {
897 os::page_info info;
898 if (os::get_page_info(p, &info)) {
899 if (info.size > 0) {
900 if (info.size > (size_t)os::vm_page_size()) {
901 space_stats()->_large_pages++;
902 } else {
903 space_stats()->_small_pages++;
904 }
905 if (info.lgrp_id == lgrp_id()) {
906 space_stats()->_local_space += info.size;
907 } else {
908 space_stats()->_remote_space += info.size;
909 }
910 p += info.size;
911 } else {
912 p += os::vm_page_size();
913 space_stats()->_uncommited_space += os::vm_page_size();
914 }
915 } else {
916 return;
917 }
918 }
919 }
920 space_stats()->_unbiased_space = pointer_delta(start, space()->bottom(), sizeof(char)) +
921 pointer_delta(space()->end(), end, sizeof(char));
922
923 }
924
925 // Scan page_count pages and verify if they have the right size and right placement.
926 // If invalid pages are found they are freed in hope that subsequent reallocation
927 // will be more successful.
928 void MutableNUMASpace::LGRPSpace::scan_pages(size_t page_size, size_t page_count)
929 {
930 char* range_start = (char*)align_up(space()->bottom(), page_size);
931 char* range_end = (char*)align_down(space()->end(), page_size);
932
933 if (range_start > last_page_scanned() || last_page_scanned() >= range_end) {
934 set_last_page_scanned(range_start);
935 }
936
937 char *scan_start = last_page_scanned();
938 char* scan_end = MIN2(scan_start + page_size * page_count, range_end);
939
940 os::page_info page_expected, page_found;
941 page_expected.size = page_size;
942 page_expected.lgrp_id = lgrp_id();
943
944 char *s = scan_start;
945 while (s < scan_end) {
946 char *e = os::scan_pages(s, (char*)scan_end, &page_expected, &page_found);
947 if (e == NULL) {
948 break;
949 }
950 if (e != scan_end) {
951 assert(e < scan_end, "e: " PTR_FORMAT " scan_end: " PTR_FORMAT, p2i(e), p2i(scan_end));
952
953 if ((page_expected.size != page_size || page_expected.lgrp_id != lgrp_id())
954 && page_expected.size != 0) {
955 os::free_memory(s, pointer_delta(e, s, sizeof(char)), page_size);
956 }
957 page_expected = page_found;
958 }
959 s = e;
960 }
961
962 set_last_page_scanned(scan_end);
963 }