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 "aot/aotLoader.hpp"
27 #include "classfile/classLoaderDataGraph.hpp"
28 #include "gc/shared/collectedHeap.hpp"
29 #include "logging/log.hpp"
30 #include "logging/logStream.hpp"
31 #include "memory/filemap.hpp"
32 #include "memory/metaspace.hpp"
33 #include "memory/metaspace/chunkManager.hpp"
34 #include "memory/metaspace/metachunk.hpp"
35 #include "memory/metaspace/metaspaceCommon.hpp"
36 #include "memory/metaspace/printCLDMetaspaceInfoClosure.hpp"
37 #include "memory/metaspace/spaceManager.hpp"
38 #include "memory/metaspace/virtualSpaceList.hpp"
39 #include "memory/metaspaceShared.hpp"
40 #include "memory/metaspaceTracer.hpp"
41 #include "memory/universe.hpp"
42 #include "oops/compressedOops.hpp"
43 #include "runtime/init.hpp"
44 #include "runtime/orderAccess.hpp"
45 #include "services/memTracker.hpp"
46 #include "utilities/copy.hpp"
47 #include "utilities/debug.hpp"
48 #include "utilities/formatBuffer.hpp"
49 #include "utilities/globalDefinitions.hpp"
50 #include "utilities/vmError.hpp"
51
52
53 using namespace metaspace;
54
55 MetaWord* last_allocated = 0;
56
57 size_t Metaspace::_compressed_class_space_size;
58 const MetaspaceTracer* Metaspace::_tracer = NULL;
59
60 DEBUG_ONLY(bool Metaspace::_frozen = false;)
61
62 static const char* space_type_name(Metaspace::MetaspaceType t) {
63 const char* s = NULL;
64 switch (t) {
65 case Metaspace::StandardMetaspaceType: s = "Standard"; break;
66 case Metaspace::BootMetaspaceType: s = "Boot"; break;
67 case Metaspace::UnsafeAnonymousMetaspaceType: s = "UnsafeAnonymous"; break;
68 case Metaspace::ReflectionMetaspaceType: s = "Reflection"; break;
69 default: ShouldNotReachHere();
70 }
71 return s;
72 }
73
74 volatile size_t MetaspaceGC::_capacity_until_GC = 0;
75 uint MetaspaceGC::_shrink_factor = 0;
76 bool MetaspaceGC::_should_concurrent_collect = false;
77
78 // BlockFreelist methods
79
80 // VirtualSpaceNode methods
81
82 // MetaspaceGC methods
83
84 // VM_CollectForMetadataAllocation is the vm operation used to GC.
85 // Within the VM operation after the GC the attempt to allocate the metadata
86 // should succeed. If the GC did not free enough space for the metaspace
87 // allocation, the HWM is increased so that another virtualspace will be
88 // allocated for the metadata. With perm gen the increase in the perm
89 // gen had bounds, MinMetaspaceExpansion and MaxMetaspaceExpansion. The
90 // metaspace policy uses those as the small and large steps for the HWM.
91 //
92 // After the GC the compute_new_size() for MetaspaceGC is called to
93 // resize the capacity of the metaspaces. The current implementation
94 // is based on the flags MinMetaspaceFreeRatio and MaxMetaspaceFreeRatio used
95 // to resize the Java heap by some GC's. New flags can be implemented
96 // if really needed. MinMetaspaceFreeRatio is used to calculate how much
97 // free space is desirable in the metaspace capacity to decide how much
98 // to increase the HWM. MaxMetaspaceFreeRatio is used to decide how much
99 // free space is desirable in the metaspace capacity before decreasing
100 // the HWM.
101
102 // Calculate the amount to increase the high water mark (HWM).
103 // Increase by a minimum amount (MinMetaspaceExpansion) so that
181 size_t MetaspaceGC::dec_capacity_until_GC(size_t v) {
182 assert_is_aligned(v, Metaspace::commit_alignment());
183
184 return Atomic::sub(v, &_capacity_until_GC);
185 }
186
187 void MetaspaceGC::initialize() {
188 // Set the high-water mark to MaxMetapaceSize during VM initializaton since
189 // we can't do a GC during initialization.
190 _capacity_until_GC = MaxMetaspaceSize;
191 }
192
193 void MetaspaceGC::post_initialize() {
194 // Reset the high-water mark once the VM initialization is done.
195 _capacity_until_GC = MAX2(MetaspaceUtils::committed_bytes(), MetaspaceSize);
196 }
197
198 bool MetaspaceGC::can_expand(size_t word_size, bool is_class) {
199 // Check if the compressed class space is full.
200 if (is_class && Metaspace::using_class_space()) {
201 size_t class_committed = MetaspaceUtils::committed_bytes(Metaspace::ClassType);
202 if (class_committed + word_size * BytesPerWord > CompressedClassSpaceSize) {
203 log_trace(gc, metaspace, freelist)("Cannot expand %s metaspace by " SIZE_FORMAT " words (CompressedClassSpaceSize = " SIZE_FORMAT " words)",
204 (is_class ? "class" : "non-class"), word_size, CompressedClassSpaceSize / sizeof(MetaWord));
205 return false;
206 }
207 }
208
209 // Check if the user has imposed a limit on the metaspace memory.
210 size_t committed_bytes = MetaspaceUtils::committed_bytes();
211 if (committed_bytes + word_size * BytesPerWord > MaxMetaspaceSize) {
212 log_trace(gc, metaspace, freelist)("Cannot expand %s metaspace by " SIZE_FORMAT " words (MaxMetaspaceSize = " SIZE_FORMAT " words)",
213 (is_class ? "class" : "non-class"), word_size, MaxMetaspaceSize / sizeof(MetaWord));
214 return false;
215 }
216
217 return true;
218 }
219
220 size_t MetaspaceGC::allowed_expansion() {
221 size_t committed_bytes = MetaspaceUtils::committed_bytes();
335 } else {
336 _shrink_factor = MIN2(current_shrink_factor * 4, (uint) 100);
337 }
338 log_trace(gc, metaspace)(" shrinking: initThreshold: %.1fK maximum_desired_capacity: %.1fK",
339 MetaspaceSize / (double) K, maximum_desired_capacity / (double) K);
340 log_trace(gc, metaspace)(" shrink_bytes: %.1fK current_shrink_factor: %d new shrink factor: %d MinMetaspaceExpansion: %.1fK",
341 shrink_bytes / (double) K, current_shrink_factor, _shrink_factor, MinMetaspaceExpansion / (double) K);
342 }
343 }
344
345 // Don't shrink unless it's significant
346 if (shrink_bytes >= MinMetaspaceExpansion &&
347 ((capacity_until_GC - shrink_bytes) >= MetaspaceSize)) {
348 size_t new_capacity_until_GC = MetaspaceGC::dec_capacity_until_GC(shrink_bytes);
349 Metaspace::tracer()->report_gc_threshold(capacity_until_GC,
350 new_capacity_until_GC,
351 MetaspaceGCThresholdUpdater::ComputeNewSize);
352 }
353 }
354
355 // MetaspaceUtils
356 size_t MetaspaceUtils::_capacity_words [Metaspace:: MetadataTypeCount] = {0, 0};
357 size_t MetaspaceUtils::_overhead_words [Metaspace:: MetadataTypeCount] = {0, 0};
358 volatile size_t MetaspaceUtils::_used_words [Metaspace:: MetadataTypeCount] = {0, 0};
359
360 // Collect used metaspace statistics. This involves walking the CLDG. The resulting
361 // output will be the accumulated values for all live metaspaces.
362 // Note: method does not do any locking.
363 void MetaspaceUtils::collect_statistics(ClassLoaderMetaspaceStatistics* out) {
364 out->reset();
365 ClassLoaderDataGraphMetaspaceIterator iter;
366 while (iter.repeat()) {
367 ClassLoaderMetaspace* msp = iter.get_next();
368 if (msp != NULL) {
369 msp->add_to_statistics(out);
370 }
371 }
372 }
373
374 size_t MetaspaceUtils::free_in_vs_bytes(Metaspace::MetadataType mdtype) {
375 VirtualSpaceList* list = Metaspace::get_space_list(mdtype);
376 return list == NULL ? 0 : list->free_bytes();
377 }
378
379 size_t MetaspaceUtils::free_in_vs_bytes() {
380 return free_in_vs_bytes(Metaspace::ClassType) + free_in_vs_bytes(Metaspace::NonClassType);
381 }
382
383 static void inc_stat_nonatomically(size_t* pstat, size_t words) {
384 assert_lock_strong(MetaspaceExpand_lock);
385 (*pstat) += words;
386 }
387
388 static void dec_stat_nonatomically(size_t* pstat, size_t words) {
389 assert_lock_strong(MetaspaceExpand_lock);
390 const size_t size_now = *pstat;
391 assert(size_now >= words, "About to decrement counter below zero "
392 "(current value: " SIZE_FORMAT ", decrement value: " SIZE_FORMAT ".",
393 size_now, words);
394 *pstat = size_now - words;
395 }
396
397 static void inc_stat_atomically(volatile size_t* pstat, size_t words) {
398 Atomic::add(words, pstat);
399 }
400
401 static void dec_stat_atomically(volatile size_t* pstat, size_t words) {
402 const size_t size_now = *pstat;
403 assert(size_now >= words, "About to decrement counter below zero "
404 "(current value: " SIZE_FORMAT ", decrement value: " SIZE_FORMAT ".",
405 size_now, words);
406 Atomic::sub(words, pstat);
407 }
408
409 void MetaspaceUtils::dec_capacity(Metaspace::MetadataType mdtype, size_t words) {
410 dec_stat_nonatomically(&_capacity_words[mdtype], words);
411 }
412 void MetaspaceUtils::inc_capacity(Metaspace::MetadataType mdtype, size_t words) {
413 inc_stat_nonatomically(&_capacity_words[mdtype], words);
414 }
415 void MetaspaceUtils::dec_used(Metaspace::MetadataType mdtype, size_t words) {
416 dec_stat_atomically(&_used_words[mdtype], words);
417 }
418 void MetaspaceUtils::inc_used(Metaspace::MetadataType mdtype, size_t words) {
419 inc_stat_atomically(&_used_words[mdtype], words);
420 }
421 void MetaspaceUtils::dec_overhead(Metaspace::MetadataType mdtype, size_t words) {
422 dec_stat_nonatomically(&_overhead_words[mdtype], words);
423 }
424 void MetaspaceUtils::inc_overhead(Metaspace::MetadataType mdtype, size_t words) {
425 inc_stat_nonatomically(&_overhead_words[mdtype], words);
426 }
427
428 size_t MetaspaceUtils::reserved_bytes(Metaspace::MetadataType mdtype) {
429 VirtualSpaceList* list = Metaspace::get_space_list(mdtype);
430 return list == NULL ? 0 : list->reserved_bytes();
431 }
432
433 size_t MetaspaceUtils::committed_bytes(Metaspace::MetadataType mdtype) {
434 VirtualSpaceList* list = Metaspace::get_space_list(mdtype);
435 return list == NULL ? 0 : list->committed_bytes();
436 }
437
438 size_t MetaspaceUtils::min_chunk_size_words() { return Metaspace::first_chunk_word_size(); }
439
440 size_t MetaspaceUtils::free_chunks_total_words(Metaspace::MetadataType mdtype) {
441 ChunkManager* chunk_manager = Metaspace::get_chunk_manager(mdtype);
442 if (chunk_manager == NULL) {
443 return 0;
444 }
445 return chunk_manager->free_chunks_total_words();
446 }
447
448 size_t MetaspaceUtils::free_chunks_total_bytes(Metaspace::MetadataType mdtype) {
449 return free_chunks_total_words(mdtype) * BytesPerWord;
450 }
451
452 size_t MetaspaceUtils::free_chunks_total_words() {
453 return free_chunks_total_words(Metaspace::ClassType) +
454 free_chunks_total_words(Metaspace::NonClassType);
455 }
456
457 size_t MetaspaceUtils::free_chunks_total_bytes() {
458 return free_chunks_total_words() * BytesPerWord;
459 }
460
461 bool MetaspaceUtils::has_chunk_free_list(Metaspace::MetadataType mdtype) {
462 return Metaspace::get_chunk_manager(mdtype) != NULL;
463 }
464
465 MetaspaceChunkFreeListSummary MetaspaceUtils::chunk_free_list_summary(Metaspace::MetadataType mdtype) {
466 if (!has_chunk_free_list(mdtype)) {
467 return MetaspaceChunkFreeListSummary();
468 }
469
470 const ChunkManager* cm = Metaspace::get_chunk_manager(mdtype);
471 return cm->chunk_free_list_summary();
472 }
473
474 void MetaspaceUtils::print_metaspace_change(const metaspace::MetaspaceSizesSnapshot& pre_meta_values) {
475 const metaspace::MetaspaceSizesSnapshot meta_values;
476
477 if (Metaspace::using_class_space()) {
478 log_info(gc, metaspace)(HEAP_CHANGE_FORMAT" "
479 HEAP_CHANGE_FORMAT" "
480 HEAP_CHANGE_FORMAT,
481 HEAP_CHANGE_FORMAT_ARGS("Metaspace",
482 pre_meta_values.used(),
483 pre_meta_values.committed(),
484 meta_values.used(),
485 meta_values.committed()),
486 HEAP_CHANGE_FORMAT_ARGS("NonClass",
487 pre_meta_values.non_class_used(),
488 pre_meta_values.non_class_committed(),
489 meta_values.non_class_used(),
490 meta_values.non_class_committed()),
491 HEAP_CHANGE_FORMAT_ARGS("Class",
492 pre_meta_values.class_used(),
493 pre_meta_values.class_committed(),
494 meta_values.class_used(),
495 meta_values.class_committed()));
496 } else {
497 log_info(gc, metaspace)(HEAP_CHANGE_FORMAT,
498 HEAP_CHANGE_FORMAT_ARGS("Metaspace",
499 pre_meta_values.used(),
500 pre_meta_values.committed(),
501 meta_values.used(),
502 meta_values.committed()));
503 }
504 }
505
506 void MetaspaceUtils::print_on(outputStream* out) {
507 Metaspace::MetadataType nct = Metaspace::NonClassType;
508
509 out->print_cr(" Metaspace "
510 "used " SIZE_FORMAT "K, "
511 "capacity " SIZE_FORMAT "K, "
512 "committed " SIZE_FORMAT "K, "
513 "reserved " SIZE_FORMAT "K",
514 used_bytes()/K,
515 capacity_bytes()/K,
516 committed_bytes()/K,
517 reserved_bytes()/K);
518
519 if (Metaspace::using_class_space()) {
520 Metaspace::MetadataType ct = Metaspace::ClassType;
521 out->print_cr(" class space "
522 "used " SIZE_FORMAT "K, "
523 "capacity " SIZE_FORMAT "K, "
524 "committed " SIZE_FORMAT "K, "
525 "reserved " SIZE_FORMAT "K",
526 used_bytes(ct)/K,
527 capacity_bytes(ct)/K,
528 committed_bytes(ct)/K,
529 reserved_bytes(ct)/K);
530 }
531 }
532
533
534 void MetaspaceUtils::print_vs(outputStream* out, size_t scale) {
535 const size_t reserved_nonclass_words = reserved_bytes(Metaspace::NonClassType) / sizeof(MetaWord);
536 const size_t committed_nonclass_words = committed_bytes(Metaspace::NonClassType) / sizeof(MetaWord);
537 {
538 if (Metaspace::using_class_space()) {
539 out->print(" Non-class space: ");
540 }
541 print_scaled_words(out, reserved_nonclass_words, scale, 7);
542 out->print(" reserved, ");
543 print_scaled_words_and_percentage(out, committed_nonclass_words, reserved_nonclass_words, scale, 7);
544 out->print_cr(" committed ");
545
546 if (Metaspace::using_class_space()) {
547 const size_t reserved_class_words = reserved_bytes(Metaspace::ClassType) / sizeof(MetaWord);
548 const size_t committed_class_words = committed_bytes(Metaspace::ClassType) / sizeof(MetaWord);
549 out->print(" Class space: ");
550 print_scaled_words(out, reserved_class_words, scale, 7);
551 out->print(" reserved, ");
552 print_scaled_words_and_percentage(out, committed_class_words, reserved_class_words, scale, 7);
553 out->print_cr(" committed ");
554
555 const size_t reserved_words = reserved_nonclass_words + reserved_class_words;
556 const size_t committed_words = committed_nonclass_words + committed_class_words;
557 out->print(" Both: ");
558 print_scaled_words(out, reserved_words, scale, 7);
559 out->print(" reserved, ");
560 print_scaled_words_and_percentage(out, committed_words, reserved_words, scale, 7);
561 out->print_cr(" committed ");
562 }
563 }
564 }
565
566 static void print_basic_switches(outputStream* out, size_t scale) {
567 out->print("MaxMetaspaceSize: ");
568 if (MaxMetaspaceSize >= (max_uintx) - (2 * os::vm_page_size())) {
569 // aka "very big". Default is max_uintx, but due to rounding in arg parsing the real
570 // value is smaller.
571 out->print("unlimited");
572 } else {
573 print_human_readable_size(out, MaxMetaspaceSize, scale);
574 }
575 out->cr();
576 if (Metaspace::using_class_space()) {
577 out->print("CompressedClassSpaceSize: ");
578 print_human_readable_size(out, CompressedClassSpaceSize, scale);
579 }
580 out->cr();
581 }
582
583 // This will print out a basic metaspace usage report but
584 // unlike print_report() is guaranteed not to lock or to walk the CLDG.
585 void MetaspaceUtils::print_basic_report(outputStream* out, size_t scale) {
586
587 if (!Metaspace::initialized()) {
588 out->print_cr("Metaspace not yet initialized.");
589 return;
590 }
591
592 out->cr();
593 out->print_cr("Usage:");
594
595 if (Metaspace::using_class_space()) {
596 out->print(" Non-class: ");
597 }
598
599 // In its most basic form, we do not require walking the CLDG. Instead, just print the running totals from
600 // MetaspaceUtils.
601 const size_t cap_nc = MetaspaceUtils::capacity_words(Metaspace::NonClassType);
602 const size_t overhead_nc = MetaspaceUtils::overhead_words(Metaspace::NonClassType);
603 const size_t used_nc = MetaspaceUtils::used_words(Metaspace::NonClassType);
604 const size_t free_and_waste_nc = cap_nc - overhead_nc - used_nc;
605
606 print_scaled_words(out, cap_nc, scale, 5);
607 out->print(" capacity, ");
608 print_scaled_words_and_percentage(out, used_nc, cap_nc, scale, 5);
609 out->print(" used, ");
610 print_scaled_words_and_percentage(out, free_and_waste_nc, cap_nc, scale, 5);
611 out->print(" free+waste, ");
612 print_scaled_words_and_percentage(out, overhead_nc, cap_nc, scale, 5);
613 out->print(" overhead. ");
614 out->cr();
615
616 if (Metaspace::using_class_space()) {
617 const size_t cap_c = MetaspaceUtils::capacity_words(Metaspace::ClassType);
618 const size_t overhead_c = MetaspaceUtils::overhead_words(Metaspace::ClassType);
619 const size_t used_c = MetaspaceUtils::used_words(Metaspace::ClassType);
620 const size_t free_and_waste_c = cap_c - overhead_c - used_c;
621 out->print(" Class: ");
622 print_scaled_words(out, cap_c, scale, 5);
623 out->print(" capacity, ");
624 print_scaled_words_and_percentage(out, used_c, cap_c, scale, 5);
625 out->print(" used, ");
626 print_scaled_words_and_percentage(out, free_and_waste_c, cap_c, scale, 5);
627 out->print(" free+waste, ");
628 print_scaled_words_and_percentage(out, overhead_c, cap_c, scale, 5);
629 out->print(" overhead. ");
630 out->cr();
631
632 out->print(" Both: ");
633 const size_t cap = cap_nc + cap_c;
634
635 print_scaled_words(out, cap, scale, 5);
636 out->print(" capacity, ");
637 print_scaled_words_and_percentage(out, used_nc + used_c, cap, scale, 5);
638 out->print(" used, ");
639 print_scaled_words_and_percentage(out, free_and_waste_nc + free_and_waste_c, cap, scale, 5);
640 out->print(" free+waste, ");
641 print_scaled_words_and_percentage(out, overhead_nc + overhead_c, cap, scale, 5);
642 out->print(" overhead. ");
643 out->cr();
644 }
645
646 out->cr();
647 out->print_cr("Virtual space:");
648
649 print_vs(out, scale);
650
651 out->cr();
652 out->print_cr("Chunk freelists:");
653
654 if (Metaspace::using_class_space()) {
655 out->print(" Non-Class: ");
656 }
657 print_human_readable_size(out, Metaspace::chunk_manager_metadata()->free_chunks_total_bytes(), scale);
658 out->cr();
659 if (Metaspace::using_class_space()) {
660 out->print(" Class: ");
661 print_human_readable_size(out, Metaspace::chunk_manager_class()->free_chunks_total_bytes(), scale);
662 out->cr();
663 out->print(" Both: ");
664 print_human_readable_size(out, Metaspace::chunk_manager_class()->free_chunks_total_bytes() +
665 Metaspace::chunk_manager_metadata()->free_chunks_total_bytes(), scale);
666 out->cr();
667 }
668
669 out->cr();
670
671 // Print basic settings
672 print_basic_switches(out, scale);
673
674 out->cr();
675
676 }
677
678 void MetaspaceUtils::print_report(outputStream* out, size_t scale, int flags) {
679
680 if (!Metaspace::initialized()) {
681 out->print_cr("Metaspace not yet initialized.");
682 return;
683 }
684
685 const bool print_loaders = (flags & rf_show_loaders) > 0;
686 const bool print_classes = (flags & rf_show_classes) > 0;
687 const bool print_by_chunktype = (flags & rf_break_down_by_chunktype) > 0;
688 const bool print_by_spacetype = (flags & rf_break_down_by_spacetype) > 0;
689
690 // Some report options require walking the class loader data graph.
691 PrintCLDMetaspaceInfoClosure cl(out, scale, print_loaders, print_classes, print_by_chunktype);
692 if (print_loaders) {
693 out->cr();
694 out->print_cr("Usage per loader:");
695 out->cr();
696 }
697
698 ClassLoaderDataGraph::loaded_cld_do(&cl); // collect data and optionally print
699
700 // Print totals, broken up by space type.
701 if (print_by_spacetype) {
702 out->cr();
703 out->print_cr("Usage per space type:");
704 out->cr();
705 for (int space_type = (int)Metaspace::ZeroMetaspaceType;
706 space_type < (int)Metaspace::MetaspaceTypeCount; space_type ++)
707 {
708 uintx num_loaders = cl._num_loaders_by_spacetype[space_type];
709 uintx num_classes = cl._num_classes_by_spacetype[space_type];
710 out->print("%s - " UINTX_FORMAT " %s",
711 space_type_name((Metaspace::MetaspaceType)space_type),
712 num_loaders, loaders_plural(num_loaders));
713 if (num_classes > 0) {
714 out->print(", ");
715 print_number_of_classes(out, num_classes, cl._num_classes_shared_by_spacetype[space_type]);
716 out->print(":");
717 cl._stats_by_spacetype[space_type].print_on(out, scale, print_by_chunktype);
718 } else {
719 out->print(".");
720 out->cr();
721 }
722 out->cr();
723 }
724 }
725
726 // Print totals for in-use data:
727 out->cr();
728 {
729 uintx num_loaders = cl._num_loaders;
730 out->print("Total Usage - " UINTX_FORMAT " %s, ",
731 num_loaders, loaders_plural(num_loaders));
732 print_number_of_classes(out, cl._num_classes, cl._num_classes_shared);
733 out->print(":");
734 cl._stats_total.print_on(out, scale, print_by_chunktype);
735 out->cr();
736 }
737
738 // -- Print Virtual space.
739 out->cr();
740 out->print_cr("Virtual space:");
741
742 print_vs(out, scale);
743
744 // -- Print VirtualSpaceList details.
745 if ((flags & rf_show_vslist) > 0) {
746 out->cr();
747 out->print_cr("Virtual space list%s:", Metaspace::using_class_space() ? "s" : "");
748
749 if (Metaspace::using_class_space()) {
750 out->print_cr(" Non-Class:");
751 }
752 Metaspace::space_list()->print_on(out, scale);
753 if (Metaspace::using_class_space()) {
754 out->print_cr(" Class:");
755 Metaspace::class_space_list()->print_on(out, scale);
756 }
757 }
758 out->cr();
759
760 // -- Print VirtualSpaceList map.
761 if ((flags & rf_show_vsmap) > 0) {
762 out->cr();
763 out->print_cr("Virtual space map:");
764
765 if (Metaspace::using_class_space()) {
766 out->print_cr(" Non-Class:");
767 }
768 Metaspace::space_list()->print_map(out);
769 if (Metaspace::using_class_space()) {
770 out->print_cr(" Class:");
771 Metaspace::class_space_list()->print_map(out);
772 }
773 }
774 out->cr();
775
776 // -- Print Freelists (ChunkManager) details
777 out->cr();
778 out->print_cr("Chunk freelist%s:", Metaspace::using_class_space() ? "s" : "");
779
780 ChunkManagerStatistics non_class_cm_stat;
781 Metaspace::chunk_manager_metadata()->collect_statistics(&non_class_cm_stat);
782
783 if (Metaspace::using_class_space()) {
784 out->print_cr(" Non-Class:");
785 }
786 non_class_cm_stat.print_on(out, scale);
787
788 if (Metaspace::using_class_space()) {
789 ChunkManagerStatistics class_cm_stat;
790 Metaspace::chunk_manager_class()->collect_statistics(&class_cm_stat);
791 out->print_cr(" Class:");
792 class_cm_stat.print_on(out, scale);
793 }
794
795 // As a convenience, print a summary of common waste.
796 out->cr();
797 out->print("Waste ");
798 // For all wastages, print percentages from total. As total use the total size of memory committed for metaspace.
799 const size_t committed_words = committed_bytes() / BytesPerWord;
800
801 out->print("(percentages refer to total committed size ");
802 print_scaled_words(out, committed_words, scale);
803 out->print_cr("):");
804
805 // Print space committed but not yet used by any class loader
806 const size_t unused_words_in_vs = MetaspaceUtils::free_in_vs_bytes() / BytesPerWord;
807 out->print(" Committed unused: ");
808 print_scaled_words_and_percentage(out, unused_words_in_vs, committed_words, scale, 6);
809 out->cr();
810
811 // Print waste for in-use chunks.
812 UsedChunksStatistics ucs_nonclass = cl._stats_total.nonclass_sm_stats().totals();
813 UsedChunksStatistics ucs_class = cl._stats_total.class_sm_stats().totals();
814 UsedChunksStatistics ucs_all;
815 ucs_all.add(ucs_nonclass);
816 ucs_all.add(ucs_class);
817
818 out->print(" Waste in chunks in use: ");
819 print_scaled_words_and_percentage(out, ucs_all.waste(), committed_words, scale, 6);
820 out->cr();
821 out->print(" Free in chunks in use: ");
822 print_scaled_words_and_percentage(out, ucs_all.free(), committed_words, scale, 6);
823 out->cr();
824 out->print(" Overhead in chunks in use: ");
825 print_scaled_words_and_percentage(out, ucs_all.overhead(), committed_words, scale, 6);
826 out->cr();
827
828 // Print waste in free chunks.
829 const size_t total_capacity_in_free_chunks =
830 Metaspace::chunk_manager_metadata()->free_chunks_total_words() +
831 (Metaspace::using_class_space() ? Metaspace::chunk_manager_class()->free_chunks_total_words() : 0);
832 out->print(" In free chunks: ");
833 print_scaled_words_and_percentage(out, total_capacity_in_free_chunks, committed_words, scale, 6);
834 out->cr();
835
836 // Print waste in deallocated blocks.
837 const uintx free_blocks_num =
838 cl._stats_total.nonclass_sm_stats().free_blocks_num() +
839 cl._stats_total.class_sm_stats().free_blocks_num();
840 const size_t free_blocks_cap_words =
841 cl._stats_total.nonclass_sm_stats().free_blocks_cap_words() +
842 cl._stats_total.class_sm_stats().free_blocks_cap_words();
843 out->print("Deallocated from chunks in use: ");
844 print_scaled_words_and_percentage(out, free_blocks_cap_words, committed_words, scale, 6);
845 out->print(" (" UINTX_FORMAT " blocks)", free_blocks_num);
846 out->cr();
847
848 // Print total waste.
849 const size_t total_waste = ucs_all.waste() + ucs_all.free() + ucs_all.overhead() + total_capacity_in_free_chunks
850 + free_blocks_cap_words + unused_words_in_vs;
851 out->print(" -total-: ");
852 print_scaled_words_and_percentage(out, total_waste, committed_words, scale, 6);
853 out->cr();
854
855 // Print internal statistics
856 #ifdef ASSERT
857 out->cr();
858 out->cr();
859 out->print_cr("Internal statistics:");
860 out->cr();
861 out->print_cr("Number of allocations: " UINTX_FORMAT ".", g_internal_statistics.num_allocs);
862 out->print_cr("Number of space births: " UINTX_FORMAT ".", g_internal_statistics.num_metaspace_births);
863 out->print_cr("Number of space deaths: " UINTX_FORMAT ".", g_internal_statistics.num_metaspace_deaths);
864 out->print_cr("Number of virtual space node births: " UINTX_FORMAT ".", g_internal_statistics.num_vsnodes_created);
865 out->print_cr("Number of virtual space node deaths: " UINTX_FORMAT ".", g_internal_statistics.num_vsnodes_purged);
866 out->print_cr("Number of times virtual space nodes were expanded: " UINTX_FORMAT ".", g_internal_statistics.num_committed_space_expanded);
867 out->print_cr("Number of deallocations: " UINTX_FORMAT " (" UINTX_FORMAT " external).", g_internal_statistics.num_deallocs, g_internal_statistics.num_external_deallocs);
868 out->print_cr("Allocations from deallocated blocks: " UINTX_FORMAT ".", g_internal_statistics.num_allocs_from_deallocated_blocks);
869 out->print_cr("Number of chunks added to freelist: " UINTX_FORMAT ".",
870 g_internal_statistics.num_chunks_added_to_freelist);
871 out->print_cr("Number of chunks removed from freelist: " UINTX_FORMAT ".",
872 g_internal_statistics.num_chunks_removed_from_freelist);
873 out->print_cr("Number of chunk merges: " UINTX_FORMAT ", split-ups: " UINTX_FORMAT ".",
874 g_internal_statistics.num_chunk_merges, g_internal_statistics.num_chunk_splits);
875
876 out->cr();
877 #endif
878
879 // Print some interesting settings
880 out->cr();
881 out->cr();
882 print_basic_switches(out, scale);
883
884 out->cr();
885 out->print("InitialBootClassLoaderMetaspaceSize: ");
886 print_human_readable_size(out, InitialBootClassLoaderMetaspaceSize, scale);
887
888 out->cr();
889 out->cr();
890
891 } // MetaspaceUtils::print_report()
892
893 // Prints an ASCII representation of the given space.
894 void MetaspaceUtils::print_metaspace_map(outputStream* out, Metaspace::MetadataType mdtype) {
895 MutexLocker cl(MetaspaceExpand_lock, Mutex::_no_safepoint_check_flag);
896 const bool for_class = mdtype == Metaspace::ClassType ? true : false;
897 VirtualSpaceList* const vsl = for_class ? Metaspace::class_space_list() : Metaspace::space_list();
898 if (vsl != NULL) {
899 if (for_class) {
900 if (!Metaspace::using_class_space()) {
901 out->print_cr("No Class Space.");
902 return;
903 }
904 out->print_raw("---- Metaspace Map (Class Space) ----");
905 } else {
906 out->print_raw("---- Metaspace Map (Non-Class Space) ----");
907 }
908 // Print legend:
909 out->cr();
910 out->print_cr("Chunk Types (uppercase chunks are in use): x-specialized, s-small, m-medium, h-humongous.");
911 out->cr();
912 VirtualSpaceList* const vsl = for_class ? Metaspace::class_space_list() : Metaspace::space_list();
913 vsl->print_map(out);
914 out->cr();
915 }
916 }
917
918 void MetaspaceUtils::verify_free_chunks() {
919 #ifdef ASSERT
920 Metaspace::chunk_manager_metadata()->verify(false);
921 if (Metaspace::using_class_space()) {
922 Metaspace::chunk_manager_class()->verify(false);
923 }
924 #endif
925 }
926
927 void MetaspaceUtils::verify_metrics() {
928 #ifdef ASSERT
929 // Please note: there are time windows where the internal counters are out of sync with
930 // reality. For example, when a newly created ClassLoaderMetaspace creates its first chunk -
931 // the ClassLoaderMetaspace is not yet attached to its ClassLoaderData object and hence will
932 // not be counted when iterating the CLDG. So be careful when you call this method.
933 ClassLoaderMetaspaceStatistics total_stat;
934 collect_statistics(&total_stat);
935 UsedChunksStatistics nonclass_chunk_stat = total_stat.nonclass_sm_stats().totals();
936 UsedChunksStatistics class_chunk_stat = total_stat.class_sm_stats().totals();
937
938 bool mismatch = false;
939 for (int i = 0; i < Metaspace::MetadataTypeCount; i ++) {
940 Metaspace::MetadataType mdtype = (Metaspace::MetadataType)i;
941 UsedChunksStatistics chunk_stat = total_stat.sm_stats(mdtype).totals();
942 if (capacity_words(mdtype) != chunk_stat.cap() ||
943 used_words(mdtype) != chunk_stat.used() ||
944 overhead_words(mdtype) != chunk_stat.overhead()) {
945 mismatch = true;
946 tty->print_cr("MetaspaceUtils::verify_metrics: counter mismatch for mdtype=%u:", mdtype);
947 tty->print_cr("Expected cap " SIZE_FORMAT ", used " SIZE_FORMAT ", overhead " SIZE_FORMAT ".",
948 capacity_words(mdtype), used_words(mdtype), overhead_words(mdtype));
949 tty->print_cr("Got cap " SIZE_FORMAT ", used " SIZE_FORMAT ", overhead " SIZE_FORMAT ".",
950 chunk_stat.cap(), chunk_stat.used(), chunk_stat.overhead());
951 tty->flush();
952 }
953 }
954 assert(mismatch == false, "MetaspaceUtils::verify_metrics: counter mismatch.");
955 #endif
956 }
957
958 // Metaspace methods
959
960 size_t Metaspace::_first_chunk_word_size = 0;
961 size_t Metaspace::_first_class_chunk_word_size = 0;
962
963 size_t Metaspace::_commit_alignment = 0;
964 size_t Metaspace::_reserve_alignment = 0;
965
966 VirtualSpaceList* Metaspace::_space_list = NULL;
967 VirtualSpaceList* Metaspace::_class_space_list = NULL;
968
969 ChunkManager* Metaspace::_chunk_manager_metadata = NULL;
970 ChunkManager* Metaspace::_chunk_manager_class = NULL;
971
972 bool Metaspace::_initialized = false;
973
974 #define VIRTUALSPACEMULTIPLIER 2
975
976 #ifdef _LP64
977 static const uint64_t UnscaledClassSpaceMax = (uint64_t(max_juint) + 1);
978
979 void Metaspace::set_narrow_klass_base_and_shift(address metaspace_base, address cds_base) {
980 assert(!DumpSharedSpaces, "narrow_klass is set by MetaspaceShared class.");
981 // Figure out the narrow_klass_base and the narrow_klass_shift. The
982 // narrow_klass_base is the lower of the metaspace base and the cds base
983 // (if cds is enabled). The narrow_klass_shift depends on the distance
984 // between the lower base and higher address.
985 address lower_base;
986 address higher_address;
987 #if INCLUDE_CDS
988 if (UseSharedSpaces) {
989 higher_address = MAX2((address)(cds_base + MetaspaceShared::core_spaces_size()),
990 (address)(metaspace_base + compressed_class_space_size()));
991 lower_base = MIN2(metaspace_base, cds_base);
992 } else
993 #endif
994 {
1030 (address)(metaspace_base + compressed_class_space_size()));
1031 return ((uint64_t)(higher_address - lower_base) <= UnscaledClassSpaceMax);
1032 }
1033 #endif
1034
1035 // Try to allocate the metaspace at the requested addr.
1036 void Metaspace::allocate_metaspace_compressed_klass_ptrs(char* requested_addr, address cds_base) {
1037 assert(!DumpSharedSpaces, "compress klass space is allocated by MetaspaceShared class.");
1038 assert(using_class_space(), "called improperly");
1039 assert(UseCompressedClassPointers, "Only use with CompressedKlassPtrs");
1040 assert(compressed_class_space_size() < KlassEncodingMetaspaceMax,
1041 "Metaspace size is too big");
1042 assert_is_aligned(requested_addr, _reserve_alignment);
1043 assert_is_aligned(cds_base, _reserve_alignment);
1044 assert_is_aligned(compressed_class_space_size(), _reserve_alignment);
1045
1046 // Don't use large pages for the class space.
1047 bool large_pages = false;
1048
1049 #if !(defined(AARCH64) || defined(AIX))
1050 ReservedSpace metaspace_rs = ReservedSpace(compressed_class_space_size(),
1051 _reserve_alignment,
1052 large_pages,
1053 requested_addr);
1054 #else // AARCH64
1055 ReservedSpace metaspace_rs;
1056
1057 // Our compressed klass pointers may fit nicely into the lower 32
1058 // bits.
1059 if ((uint64_t)requested_addr + compressed_class_space_size() < 4*G) {
1060 metaspace_rs = ReservedSpace(compressed_class_space_size(),
1061 _reserve_alignment,
1062 large_pages,
1063 requested_addr);
1064 }
1065
1066 if (! metaspace_rs.is_reserved()) {
1067 // Aarch64: Try to align metaspace so that we can decode a compressed
1068 // klass with a single MOVK instruction. We can do this iff the
1069 // compressed class base is a multiple of 4G.
1070 // Aix: Search for a place where we can find memory. If we need to load
1071 // the base, 4G alignment is helpful, too.
1072 size_t increment = AARCH64_ONLY(4*)G;
1073 for (char *a = align_up(requested_addr, increment);
1074 a < (char*)(1024*G);
1075 a += increment) {
1076 if (a == (char *)(32*G)) {
1077 // Go faster from here on. Zero-based is no longer possible.
1078 increment = 4*G;
1079 }
1080
1081 #if INCLUDE_CDS
1082 if (UseSharedSpaces
1083 && ! can_use_cds_with_metaspace_addr(a, cds_base)) {
1084 // We failed to find an aligned base that will reach. Fall
1085 // back to using our requested addr.
1086 metaspace_rs = ReservedSpace(compressed_class_space_size(),
1087 _reserve_alignment,
1088 large_pages,
1089 requested_addr);
1090 break;
1091 }
1092 #endif
1093
1094 metaspace_rs = ReservedSpace(compressed_class_space_size(),
1095 _reserve_alignment,
1096 large_pages,
1097 a);
1098 if (metaspace_rs.is_reserved())
1099 break;
1100 }
1101 }
1102
1103 #endif // AARCH64
1104
1105 if (!metaspace_rs.is_reserved()) {
1106 #if INCLUDE_CDS
1107 if (UseSharedSpaces) {
1108 size_t increment = align_up(1*G, _reserve_alignment);
1109
1110 // Keep trying to allocate the metaspace, increasing the requested_addr
1111 // by 1GB each time, until we reach an address that will no longer allow
1112 // use of CDS with compressed klass pointers.
1113 char *addr = requested_addr;
1114 while (!metaspace_rs.is_reserved() && (addr + increment > addr) &&
1115 can_use_cds_with_metaspace_addr(addr + increment, cds_base)) {
1116 addr = addr + increment;
1117 metaspace_rs = ReservedSpace(compressed_class_space_size(),
1118 _reserve_alignment, large_pages, addr);
1119 }
1120 }
1121 #endif
1122 // If no successful allocation then try to allocate the space anywhere. If
1123 // that fails then OOM doom. At this point we cannot try allocating the
1124 // metaspace as if UseCompressedClassPointers is off because too much
1125 // initialization has happened that depends on UseCompressedClassPointers.
1126 // So, UseCompressedClassPointers cannot be turned off at this point.
1127 if (!metaspace_rs.is_reserved()) {
1128 metaspace_rs = ReservedSpace(compressed_class_space_size(),
1129 _reserve_alignment, large_pages);
1130 if (!metaspace_rs.is_reserved()) {
1131 vm_exit_during_initialization(err_msg("Could not allocate metaspace: " SIZE_FORMAT " bytes",
1132 compressed_class_space_size()));
1133 }
1134 }
1135 }
1136
1137 // If we got here then the metaspace got allocated.
1138 MemTracker::record_virtual_memory_type((address)metaspace_rs.base(), mtClass);
1139
1140 #if INCLUDE_CDS
1141 // Verify that we can use shared spaces. Otherwise, turn off CDS.
1142 if (UseSharedSpaces && !can_use_cds_with_metaspace_addr(metaspace_rs.base(), cds_base)) {
1143 FileMapInfo::stop_sharing_and_unmap(
1144 "Could not allocate metaspace at a compatible address");
1145 }
1146 #endif
1147 set_narrow_klass_base_and_shift((address)metaspace_rs.base(),
1148 UseSharedSpaces ? (address)cds_base : 0);
1149
1150 initialize_class_space(metaspace_rs);
1151
1152 LogTarget(Trace, gc, metaspace) lt;
1153 if (lt.is_enabled()) {
1154 ResourceMark rm;
1155 LogStream ls(lt);
1156 print_compressed_class_space(&ls, requested_addr);
1157 }
1158 }
1159
1160 void Metaspace::print_compressed_class_space(outputStream* st, const char* requested_addr) {
1161 st->print_cr("Narrow klass base: " PTR_FORMAT ", Narrow klass shift: %d",
1162 p2i(CompressedKlassPointers::base()), CompressedKlassPointers::shift());
1163 if (_class_space_list != NULL) {
1164 address base = (address)_class_space_list->current_virtual_space()->bottom();
1165 st->print("Compressed class space size: " SIZE_FORMAT " Address: " PTR_FORMAT,
1166 compressed_class_space_size(), p2i(base));
1167 if (requested_addr != 0) {
1168 st->print(" Req Addr: " PTR_FORMAT, p2i(requested_addr));
1169 }
1170 st->cr();
1171 }
1172 }
1173
1174 // For UseCompressedClassPointers the class space is reserved above the top of
1175 // the Java heap. The argument passed in is at the base of the compressed space.
1176 void Metaspace::initialize_class_space(ReservedSpace rs) {
1177 // The reserved space size may be bigger because of alignment, esp with UseLargePages
1178 assert(rs.size() >= CompressedClassSpaceSize,
1179 SIZE_FORMAT " != " SIZE_FORMAT, rs.size(), CompressedClassSpaceSize);
1180 assert(using_class_space(), "Must be using class space");
1181 _class_space_list = new VirtualSpaceList(rs);
1182 _chunk_manager_class = new ChunkManager(true/*is_class*/);
1183
1184 if (!_class_space_list->initialization_succeeded()) {
1185 vm_exit_during_initialization("Failed to setup compressed class space virtual space list.");
1186 }
1187 }
1188
1189 #endif
1190
1191 void Metaspace::ergo_initialize() {
1192 if (DumpSharedSpaces) {
1193 // Using large pages when dumping the shared archive is currently not implemented.
1194 FLAG_SET_ERGO(UseLargePagesInMetaspace, false);
1195 }
1196
1197 size_t page_size = os::vm_page_size();
1198 if (UseLargePages && UseLargePagesInMetaspace) {
1199 page_size = os::large_page_size();
1200 }
1201
1202 _commit_alignment = page_size;
1203 _reserve_alignment = MAX2(page_size, (size_t)os::vm_allocation_granularity());
1204
1205 // Do not use FLAG_SET_ERGO to update MaxMetaspaceSize, since this will
1206 // override if MaxMetaspaceSize was set on the command line or not.
1207 // This information is needed later to conform to the specification of the
1208 // java.lang.management.MemoryUsage API.
1209 //
1210 // Ideally, we would be able to set the default value of MaxMetaspaceSize in
1211 // globals.hpp to the aligned value, but this is not possible, since the
1212 // alignment depends on other flags being parsed.
1213 MaxMetaspaceSize = align_down_bounded(MaxMetaspaceSize, _reserve_alignment);
1214
1215 if (MetaspaceSize > MaxMetaspaceSize) {
1216 MetaspaceSize = MaxMetaspaceSize;
1217 }
1218
1219 MetaspaceSize = align_down_bounded(MetaspaceSize, _commit_alignment);
1220
1221 assert(MetaspaceSize <= MaxMetaspaceSize, "MetaspaceSize should be limited by MaxMetaspaceSize");
1222
1223 MinMetaspaceExpansion = align_down_bounded(MinMetaspaceExpansion, _commit_alignment);
1224 MaxMetaspaceExpansion = align_down_bounded(MaxMetaspaceExpansion, _commit_alignment);
1225
1226 CompressedClassSpaceSize = align_down_bounded(CompressedClassSpaceSize, _reserve_alignment);
1227
1228 // Initial virtual space size will be calculated at global_initialize()
1229 size_t min_metaspace_sz =
1230 VIRTUALSPACEMULTIPLIER * InitialBootClassLoaderMetaspaceSize;
1231 if (UseCompressedClassPointers) {
1232 if ((min_metaspace_sz + CompressedClassSpaceSize) > MaxMetaspaceSize) {
1233 if (min_metaspace_sz >= MaxMetaspaceSize) {
1234 vm_exit_during_initialization("MaxMetaspaceSize is too small.");
1235 } else {
1236 FLAG_SET_ERGO(CompressedClassSpaceSize,
1237 MaxMetaspaceSize - min_metaspace_sz);
1238 }
1239 }
1240 } else if (min_metaspace_sz >= MaxMetaspaceSize) {
1241 FLAG_SET_ERGO(InitialBootClassLoaderMetaspaceSize,
1242 min_metaspace_sz);
1243 }
1244
1245 set_compressed_class_space_size(CompressedClassSpaceSize);
1246 }
1247
1248 void Metaspace::global_initialize() {
1249 MetaspaceGC::initialize();
1250
1251 #if INCLUDE_CDS
1252 if (DumpSharedSpaces) {
1253 MetaspaceShared::initialize_dumptime_shared_and_meta_spaces();
1254 } else if (UseSharedSpaces) {
1255 // If any of the archived space fails to map, UseSharedSpaces
1256 // is reset to false. Fall through to the
1257 // (!DumpSharedSpaces && !UseSharedSpaces) case to set up class
1258 // metaspace.
1259 MetaspaceShared::initialize_runtime_shared_and_meta_spaces();
1260 }
1261
1262 if (DynamicDumpSharedSpaces && !UseSharedSpaces) {
1263 vm_exit_during_initialization("DynamicDumpSharedSpaces is unsupported when base CDS archive is not loaded", NULL);
1264 }
1265
1266 if (!DumpSharedSpaces && !UseSharedSpaces)
1267 #endif // INCLUDE_CDS
1268 {
1269 #ifdef _LP64
1270 if (using_class_space()) {
1271 char* base = (char*)align_up(Universe::heap()->reserved_region().end(), _reserve_alignment);
1272 allocate_metaspace_compressed_klass_ptrs(base, 0);
1273 }
1274 #endif // _LP64
1275 }
1276
1277 // Initialize these before initializing the VirtualSpaceList
1278 _first_chunk_word_size = InitialBootClassLoaderMetaspaceSize / BytesPerWord;
1279 _first_chunk_word_size = align_word_size_up(_first_chunk_word_size);
1280 // Make the first class chunk bigger than a medium chunk so it's not put
1281 // on the medium chunk list. The next chunk will be small and progress
1282 // from there. This size calculated by -version.
1283 _first_class_chunk_word_size = MIN2((size_t)MediumChunk*6,
1284 (CompressedClassSpaceSize/BytesPerWord)*2);
1285 _first_class_chunk_word_size = align_word_size_up(_first_class_chunk_word_size);
1286 // Arbitrarily set the initial virtual space to a multiple
1287 // of the boot class loader size.
1288 size_t word_size = VIRTUALSPACEMULTIPLIER * _first_chunk_word_size;
1289 word_size = align_up(word_size, Metaspace::reserve_alignment_words());
1290
1291 // Initialize the list of virtual spaces.
1292 _space_list = new VirtualSpaceList(word_size);
1293 _chunk_manager_metadata = new ChunkManager(false/*metaspace*/);
1294
1295 if (!_space_list->initialization_succeeded()) {
1296 vm_exit_during_initialization("Unable to setup metadata virtual space list.", NULL);
1297 }
1298
1299 _tracer = new MetaspaceTracer();
1300
1301 _initialized = true;
1302
1303 }
1304
1305 void Metaspace::post_initialize() {
1306 MetaspaceGC::post_initialize();
1307 }
1308
1309 void Metaspace::verify_global_initialization() {
1310 assert(space_list() != NULL, "Metadata VirtualSpaceList has not been initialized");
1311 assert(chunk_manager_metadata() != NULL, "Metadata ChunkManager has not been initialized");
1312
1313 if (using_class_space()) {
1314 assert(class_space_list() != NULL, "Class VirtualSpaceList has not been initialized");
1315 assert(chunk_manager_class() != NULL, "Class ChunkManager has not been initialized");
1316 }
1317 }
1318
1319 size_t Metaspace::align_word_size_up(size_t word_size) {
1320 size_t byte_size = word_size * wordSize;
1321 return ReservedSpace::allocation_align_size_up(byte_size) / wordSize;
1322 }
1323
1324 MetaWord* Metaspace::allocate(ClassLoaderData* loader_data, size_t word_size,
1325 MetaspaceObj::Type type, TRAPS) {
1326 assert(!_frozen, "sanity");
1327 assert(!(DumpSharedSpaces && THREAD->is_VM_thread()), "sanity");
1328
1329 if (HAS_PENDING_EXCEPTION) {
1330 assert(false, "Should not allocate with exception pending");
1331 return NULL; // caller does a CHECK_NULL too
1332 }
1333
1334 assert(loader_data != NULL, "Should never pass around a NULL loader_data. "
1335 "ClassLoaderData::the_null_class_loader_data() should have been used.");
1336
1337 MetadataType mdtype = (type == MetaspaceObj::ClassType) ? ClassType : NonClassType;
1338
1339 // Try to allocate metadata.
1340 MetaWord* result = loader_data->metaspace_non_null()->allocate(word_size, mdtype);
1341
1342 if (result == NULL) {
1343 tracer()->report_metaspace_allocation_failure(loader_data, word_size, type, mdtype);
1344
1345 // Allocation failed.
1346 if (is_init_completed()) {
1347 // Only start a GC if the bootstrapping has completed.
1348 // Try to clean out some heap memory and retry. This can prevent premature
1349 // expansion of the metaspace.
1350 result = Universe::heap()->satisfy_failed_metadata_allocation(loader_data, word_size, mdtype);
1351 }
1352 }
1353
1354 if (result == NULL) {
1355 if (DumpSharedSpaces) {
1356 // CDS dumping keeps loading classes, so if we hit an OOM we probably will keep hitting OOM.
1357 // We should abort to avoid generating a potentially bad archive.
1360 err_msg("Please increase MaxMetaspaceSize (currently " SIZE_FORMAT " bytes).", MaxMetaspaceSize));
1361 }
1362 report_metadata_oome(loader_data, word_size, type, mdtype, THREAD);
1363 assert(HAS_PENDING_EXCEPTION, "sanity");
1364 return NULL;
1365 }
1366
1367 // Zero initialize.
1368 Copy::fill_to_words((HeapWord*)result, word_size, 0);
1369
1370 return result;
1371 }
1372
1373 void Metaspace::report_metadata_oome(ClassLoaderData* loader_data, size_t word_size, MetaspaceObj::Type type, MetadataType mdtype, TRAPS) {
1374 tracer()->report_metadata_oom(loader_data, word_size, type, mdtype);
1375
1376 // If result is still null, we are out of memory.
1377 Log(gc, metaspace, freelist, oom) log;
1378 if (log.is_info()) {
1379 log.info("Metaspace (%s) allocation failed for size " SIZE_FORMAT,
1380 is_class_space_allocation(mdtype) ? "class" : "data", word_size);
1381 ResourceMark rm;
1382 if (log.is_debug()) {
1383 if (loader_data->metaspace_or_null() != NULL) {
1384 LogStream ls(log.debug());
1385 loader_data->print_value_on(&ls);
1386 }
1387 }
1388 LogStream ls(log.info());
1389 // In case of an OOM, log out a short but still useful report.
1390 MetaspaceUtils::print_basic_report(&ls, 0);
1391 }
1392
1393 bool out_of_compressed_class_space = false;
1394 if (is_class_space_allocation(mdtype)) {
1395 ClassLoaderMetaspace* metaspace = loader_data->metaspace_non_null();
1396 out_of_compressed_class_space =
1397 MetaspaceUtils::committed_bytes(Metaspace::ClassType) +
1398 (metaspace->class_chunk_size(word_size) * BytesPerWord) >
1399 CompressedClassSpaceSize;
1400 }
1401
1402 // -XX:+HeapDumpOnOutOfMemoryError and -XX:OnOutOfMemoryError support
1403 const char* space_string = out_of_compressed_class_space ?
1404 "Compressed class space" : "Metaspace";
1405
1406 report_java_out_of_memory(space_string);
1407
1408 if (JvmtiExport::should_post_resource_exhausted()) {
1409 JvmtiExport::post_resource_exhausted(
1410 JVMTI_RESOURCE_EXHAUSTED_OOM_ERROR,
1411 space_string);
1412 }
1413
1414 if (!is_init_completed()) {
1415 vm_exit_during_initialization("OutOfMemoryError", space_string);
1416 }
1417
1418 if (out_of_compressed_class_space) {
1419 THROW_OOP(Universe::out_of_memory_error_class_metaspace());
1420 } else {
1421 THROW_OOP(Universe::out_of_memory_error_metaspace());
1422 }
1423 }
1424
1425 const char* Metaspace::metadata_type_name(Metaspace::MetadataType mdtype) {
1426 switch (mdtype) {
1427 case Metaspace::ClassType: return "Class";
1428 case Metaspace::NonClassType: return "Metadata";
1429 default:
1430 assert(false, "Got bad mdtype: %d", (int) mdtype);
1431 return NULL;
1432 }
1433 }
1434
1435 void Metaspace::purge(MetadataType mdtype) {
1436 get_space_list(mdtype)->purge(get_chunk_manager(mdtype));
1437 }
1438
1439 void Metaspace::purge() {
1440 MutexLocker cl(MetaspaceExpand_lock,
1441 Mutex::_no_safepoint_check_flag);
1442 purge(NonClassType);
1443 if (using_class_space()) {
1444 purge(ClassType);
1445 }
1446 }
1447
1448 bool Metaspace::contains(const void* ptr) {
1449 if (MetaspaceShared::is_in_shared_metaspace(ptr)) {
1450 return true;
1451 }
1452 return contains_non_shared(ptr);
1453 }
1454
1455 bool Metaspace::contains_non_shared(const void* ptr) {
1456 if (using_class_space() && get_space_list(ClassType)->contains(ptr)) {
1457 return true;
1458 }
1459
1460 return get_space_list(NonClassType)->contains(ptr);
1461 }
1462
1463 // ClassLoaderMetaspace
1464
1465 ClassLoaderMetaspace::ClassLoaderMetaspace(Mutex* lock, Metaspace::MetaspaceType type)
1466 : _space_type(type)
1467 , _lock(lock)
1468 , _vsm(NULL)
1469 , _class_vsm(NULL)
1470 {
1471 initialize(lock, type);
1472 }
1473
1474 ClassLoaderMetaspace::~ClassLoaderMetaspace() {
1475 Metaspace::assert_not_frozen();
1476 DEBUG_ONLY(Atomic::inc(&g_internal_statistics.num_metaspace_deaths));
1477 delete _vsm;
1478 if (Metaspace::using_class_space()) {
1479 delete _class_vsm;
1480 }
1481 }
1482
1483 void ClassLoaderMetaspace::initialize_first_chunk(Metaspace::MetaspaceType type, Metaspace::MetadataType mdtype) {
1484 Metachunk* chunk = get_initialization_chunk(type, mdtype);
1485 if (chunk != NULL) {
1486 // Add to this manager's list of chunks in use and make it the current_chunk().
1487 get_space_manager(mdtype)->add_chunk(chunk, true);
1488 }
1489 }
1490
1491 Metachunk* ClassLoaderMetaspace::get_initialization_chunk(Metaspace::MetaspaceType type, Metaspace::MetadataType mdtype) {
1492 size_t chunk_word_size = get_space_manager(mdtype)->get_initial_chunk_size(type);
1493
1494 // Get a chunk from the chunk freelist
1495 Metachunk* chunk = Metaspace::get_chunk_manager(mdtype)->chunk_freelist_allocate(chunk_word_size);
1496
1497 if (chunk == NULL) {
1498 chunk = Metaspace::get_space_list(mdtype)->get_new_chunk(chunk_word_size,
1499 get_space_manager(mdtype)->medium_chunk_bunch());
1500 }
1501
1502 return chunk;
1503 }
1504
1505 void ClassLoaderMetaspace::initialize(Mutex* lock, Metaspace::MetaspaceType type) {
1506 Metaspace::verify_global_initialization();
1507
1508 DEBUG_ONLY(Atomic::inc(&g_internal_statistics.num_metaspace_births));
1509
1510 // Allocate SpaceManager for metadata objects.
1511 _vsm = new SpaceManager(Metaspace::NonClassType, type, lock);
1512
1513 if (Metaspace::using_class_space()) {
1514 // Allocate SpaceManager for classes.
1515 _class_vsm = new SpaceManager(Metaspace::ClassType, type, lock);
1516 }
1517
1518 MutexLocker cl(MetaspaceExpand_lock, Mutex::_no_safepoint_check_flag);
1519
1520 // Allocate chunk for metadata objects
1521 initialize_first_chunk(type, Metaspace::NonClassType);
1522
1523 // Allocate chunk for class metadata objects
1524 if (Metaspace::using_class_space()) {
1525 initialize_first_chunk(type, Metaspace::ClassType);
1526 }
1527 }
1528
1529 MetaWord* ClassLoaderMetaspace::allocate(size_t word_size, Metaspace::MetadataType mdtype) {
1530 Metaspace::assert_not_frozen();
1531
1532 DEBUG_ONLY(Atomic::inc(&g_internal_statistics.num_allocs));
1533
1534 // Don't use class_vsm() unless UseCompressedClassPointers is true.
1535 if (Metaspace::is_class_space_allocation(mdtype)) {
1536 return class_vsm()->allocate(word_size);
1537 } else {
1538 return vsm()->allocate(word_size);
1539 }
1540 }
1541
1542 MetaWord* ClassLoaderMetaspace::expand_and_allocate(size_t word_size, Metaspace::MetadataType mdtype) {
1543 Metaspace::assert_not_frozen();
1544 size_t delta_bytes = MetaspaceGC::delta_capacity_until_GC(word_size * BytesPerWord);
1545 assert(delta_bytes > 0, "Must be");
1546
1547 size_t before = 0;
1548 size_t after = 0;
1549 bool can_retry = true;
1550 MetaWord* res;
1551 bool incremented;
1552
1553 // Each thread increments the HWM at most once. Even if the thread fails to increment
1554 // the HWM, an allocation is still attempted. This is because another thread must then
1555 // have incremented the HWM and therefore the allocation might still succeed.
1556 do {
1557 incremented = MetaspaceGC::inc_capacity_until_GC(delta_bytes, &after, &before, &can_retry);
1558 res = allocate(word_size, mdtype);
1559 } while (!incremented && res == NULL && can_retry);
1560
1561 if (incremented) {
1562 Metaspace::tracer()->report_gc_threshold(before, after,
1563 MetaspaceGCThresholdUpdater::ExpandAndAllocate);
1564 log_trace(gc, metaspace)("Increase capacity to GC from " SIZE_FORMAT " to " SIZE_FORMAT, before, after);
1565 }
1566
1567 return res;
1568 }
1569
1570 size_t ClassLoaderMetaspace::allocated_blocks_bytes() const {
1571 return (vsm()->used_words() +
1572 (Metaspace::using_class_space() ? class_vsm()->used_words() : 0)) * BytesPerWord;
1573 }
1574
1575 size_t ClassLoaderMetaspace::allocated_chunks_bytes() const {
1576 return (vsm()->capacity_words() +
1577 (Metaspace::using_class_space() ? class_vsm()->capacity_words() : 0)) * BytesPerWord;
1578 }
1579
1580 void ClassLoaderMetaspace::deallocate(MetaWord* ptr, size_t word_size, bool is_class) {
1581 Metaspace::assert_not_frozen();
1582 assert(!SafepointSynchronize::is_at_safepoint()
1583 || Thread::current()->is_VM_thread(), "should be the VM thread");
1584
1585 DEBUG_ONLY(Atomic::inc(&g_internal_statistics.num_external_deallocs));
1586
1587 MutexLocker ml(vsm()->lock(), Mutex::_no_safepoint_check_flag);
1588
1589 if (is_class && Metaspace::using_class_space()) {
1590 class_vsm()->deallocate(ptr, word_size);
1591 } else {
1592 vsm()->deallocate(ptr, word_size);
1593 }
1594 }
1595
1596 size_t ClassLoaderMetaspace::class_chunk_size(size_t word_size) {
1597 assert(Metaspace::using_class_space(), "Has to use class space");
1598 return class_vsm()->calc_chunk_size(word_size);
1599 }
1600
1601 void ClassLoaderMetaspace::print_on(outputStream* out) const {
1602 // Print both class virtual space counts and metaspace.
1603 if (Verbose) {
1604 vsm()->print_on(out);
1605 if (Metaspace::using_class_space()) {
1606 class_vsm()->print_on(out);
1607 }
1608 }
1609 }
1610
1611 void ClassLoaderMetaspace::verify() {
1612 vsm()->verify();
1613 if (Metaspace::using_class_space()) {
1614 class_vsm()->verify();
1615 }
1616 }
1617
1618 void ClassLoaderMetaspace::add_to_statistics_locked(ClassLoaderMetaspaceStatistics* out) const {
1619 assert_lock_strong(lock());
1620 vsm()->add_to_statistics_locked(&out->nonclass_sm_stats());
1621 if (Metaspace::using_class_space()) {
1622 class_vsm()->add_to_statistics_locked(&out->class_sm_stats());
1623 }
1624 }
1625
1626 void ClassLoaderMetaspace::add_to_statistics(ClassLoaderMetaspaceStatistics* out) const {
1627 MutexLocker cl(lock(), Mutex::_no_safepoint_check_flag);
1628 add_to_statistics_locked(out);
1629 }
1630
1631 /////////////// Unit tests ///////////////
1632
1633 struct chunkmanager_statistics_t {
1634 int num_specialized_chunks;
1635 int num_small_chunks;
1636 int num_medium_chunks;
1637 int num_humongous_chunks;
1638 };
1639
1640 extern void test_metaspace_retrieve_chunkmanager_statistics(Metaspace::MetadataType mdType, chunkmanager_statistics_t* out) {
1641 ChunkManager* const chunk_manager = Metaspace::get_chunk_manager(mdType);
1642 ChunkManagerStatistics stat;
1643 chunk_manager->collect_statistics(&stat);
1644 out->num_specialized_chunks = (int)stat.chunk_stats(SpecializedIndex).num();
1645 out->num_small_chunks = (int)stat.chunk_stats(SmallIndex).num();
1646 out->num_medium_chunks = (int)stat.chunk_stats(MediumIndex).num();
1647 out->num_humongous_chunks = (int)stat.chunk_stats(HumongousIndex).num();
1648 }
1649
1650 struct chunk_geometry_t {
1651 size_t specialized_chunk_word_size;
1652 size_t small_chunk_word_size;
1653 size_t medium_chunk_word_size;
1654 };
1655
1656 extern void test_metaspace_retrieve_chunk_geometry(Metaspace::MetadataType mdType, chunk_geometry_t* out) {
1657 if (mdType == Metaspace::NonClassType) {
1658 out->specialized_chunk_word_size = SpecializedChunk;
1659 out->small_chunk_word_size = SmallChunk;
1660 out->medium_chunk_word_size = MediumChunk;
1661 } else {
1662 out->specialized_chunk_word_size = ClassSpecializedChunk;
1663 out->small_chunk_word_size = ClassSmallChunk;
1664 out->medium_chunk_word_size = ClassMediumChunk;
1665 }
1666 }
|
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
27 #include "aot/aotLoader.hpp"
28 #include "gc/shared/collectedHeap.hpp"
29 #include "logging/log.hpp"
30 #include "logging/logStream.hpp"
31 #include "memory/filemap.hpp"
32 #include "memory/metaspace.hpp"
33 #include "memory/metaspaceShared.hpp"
34 #include "memory/metaspaceTracer.hpp"
35 #include "memory/metaspace/chunkManager.hpp"
36 #include "memory/metaspace/classLoaderMetaspace.hpp"
37 #include "memory/metaspace/commitLimiter.hpp"
38 #include "memory/metaspace/metaspaceCommon.hpp"
39 #include "memory/metaspace/metaspaceEnums.hpp"
40 #include "memory/metaspace/metaspaceReport.hpp"
41 #include "memory/metaspace/metaspaceSizesSnapshot.hpp"
42 #include "memory/metaspace/runningCounters.hpp"
43 #include "memory/metaspace/virtualSpaceList.hpp"
44 #include "memory/universe.hpp"
45 #include "oops/compressedOops.hpp"
46 #include "runtime/init.hpp"
47 #include "runtime/java.hpp"
48 #include "runtime/orderAccess.hpp"
49 #include "services/memTracker.hpp"
50 #include "utilities/copy.hpp"
51 #include "utilities/debug.hpp"
52 #include "utilities/formatBuffer.hpp"
53 #include "utilities/globalDefinitions.hpp"
54
55
56 using metaspace::ChunkManager;
57 using metaspace::ClassLoaderMetaspace;
58 using metaspace::CommitLimiter;
59 using metaspace::MetaspaceType;
60 using metaspace::MetadataType;
61 using metaspace::MetaspaceReporter;
62 using metaspace::RunningCounters;
63 using metaspace::VirtualSpaceList;
64
65
66 // Used by MetaspaceCounters
67 size_t MetaspaceUtils::free_chunks_total_words(MetadataType mdtype) {
68 return is_class(mdtype) ? RunningCounters::free_chunks_words_class() : RunningCounters::free_chunks_words_nonclass();
69 }
70
71 size_t MetaspaceUtils::used_words() {
72 return RunningCounters::used_words();
73 }
74
75 size_t MetaspaceUtils::used_words(MetadataType mdtype) {
76 return is_class(mdtype) ? RunningCounters::used_words_class() : RunningCounters::used_words_nonclass();
77 }
78
79 size_t MetaspaceUtils::reserved_words() {
80 return RunningCounters::reserved_words();
81 }
82
83 size_t MetaspaceUtils::reserved_words(MetadataType mdtype) {
84 return is_class(mdtype) ? RunningCounters::reserved_words_class() : RunningCounters::reserved_words_nonclass();
85 }
86
87 size_t MetaspaceUtils::committed_words() {
88 return RunningCounters::committed_words();
89 }
90
91 size_t MetaspaceUtils::committed_words(MetadataType mdtype) {
92 return is_class(mdtype) ? RunningCounters::committed_words_class() : RunningCounters::committed_words_nonclass();
93 }
94
95
96
97 void MetaspaceUtils::print_metaspace_change(const metaspace::MetaspaceSizesSnapshot& pre_meta_values) {
98 const metaspace::MetaspaceSizesSnapshot meta_values;
99
100 // We print used and committed since these are the most useful at-a-glance vitals for Metaspace:
101 // - used tells you how much memory is actually used for metadata
102 // - committed tells you how much memory is committed for the purpose of metadata
103 // The difference between those two would be waste, which can have various forms (freelists,
104 // unused parts of committed chunks etc)
105 //
106 // Left out is reserved, since this is not as exciting as the first two values: for class space,
107 // it is a constant (to uninformed users, often confusingly large). For non-class space, it would
108 // be interesting since free chunks can be uncommitted, but for now it is left out.
109
110 if (Metaspace::using_class_space()) {
111 log_info(gc, metaspace)(HEAP_CHANGE_FORMAT" "
112 HEAP_CHANGE_FORMAT" "
113 HEAP_CHANGE_FORMAT,
114 HEAP_CHANGE_FORMAT_ARGS("Metaspace",
115 pre_meta_values.used(),
116 pre_meta_values.committed(),
117 meta_values.used(),
118 meta_values.committed()),
119 HEAP_CHANGE_FORMAT_ARGS("NonClass",
120 pre_meta_values.non_class_used(),
121 pre_meta_values.non_class_committed(),
122 meta_values.non_class_used(),
123 meta_values.non_class_committed()),
124 HEAP_CHANGE_FORMAT_ARGS("Class",
125 pre_meta_values.class_used(),
126 pre_meta_values.class_committed(),
127 meta_values.class_used(),
128 meta_values.class_committed()));
129 } else {
130 log_info(gc, metaspace)(HEAP_CHANGE_FORMAT,
131 HEAP_CHANGE_FORMAT_ARGS("Metaspace",
132 pre_meta_values.used(),
133 pre_meta_values.committed(),
134 meta_values.used(),
135 meta_values.committed()));
136 }
137 }
138
139
140 // Prints an ASCII representation of the given space.
141 void MetaspaceUtils::print_metaspace_map(outputStream* out, MetadataType mdtype) {
142 out->print_cr("-- not yet implemented ---");
143 }
144
145 // This will print out a basic metaspace usage report but
146 // unlike print_report() is guaranteed not to lock or to walk the CLDG.
147 void MetaspaceUtils::print_basic_report(outputStream* out, size_t scale) {
148 MetaspaceReporter::print_basic_report(out, scale);
149 }
150
151 // Prints a report about the current metaspace state.
152 // Optional parts can be enabled via flags.
153 // Function will walk the CLDG and will lock the expand lock; if that is not
154 // convenient, use print_basic_report() instead.
155 void MetaspaceUtils::print_full_report(outputStream* out, size_t scale) {
156 const int flags =
157 MetaspaceReporter::rf_show_loaders |
158 MetaspaceReporter::rf_break_down_by_chunktype |
159 MetaspaceReporter::rf_show_classes;
160 MetaspaceReporter::print_report(out, scale, flags);
161 }
162
163 void MetaspaceUtils::print_on(outputStream* out) {
164
165 // Used from all GCs. It first prints out totals, then, separately, the class space portion.
166
167 out->print_cr(" Metaspace "
168 "used " SIZE_FORMAT "K, "
169 "committed " SIZE_FORMAT "K, "
170 "reserved " SIZE_FORMAT "K",
171 used_bytes()/K,
172 committed_bytes()/K,
173 reserved_bytes()/K);
174
175 if (Metaspace::using_class_space()) {
176 const MetadataType ct = metaspace::ClassType;
177 out->print_cr(" class space "
178 "used " SIZE_FORMAT "K, "
179 "committed " SIZE_FORMAT "K, "
180 "reserved " SIZE_FORMAT "K",
181 used_bytes(ct)/K,
182 committed_bytes(ct)/K,
183 reserved_bytes(ct)/K);
184 }
185 }
186
187 #ifdef ASSERT
188 void MetaspaceUtils::verify(bool slow) {
189 if (Metaspace::initialized()) {
190
191 // Verify non-class chunkmanager...
192 ChunkManager* cm = ChunkManager::chunkmanager_nonclass();
193 cm->verify(slow);
194
195 // ... and space list.
196 VirtualSpaceList* vsl = VirtualSpaceList::vslist_nonclass();
197 vsl->verify(slow);
198
199 if (Metaspace::using_class_space()) {
200 // If we use compressed class pointers, verify class chunkmanager...
201 cm = ChunkManager::chunkmanager_class();
202 assert(cm != NULL, "Sanity");
203 cm->verify(slow);
204
205 // ... and class spacelist.
206 VirtualSpaceList* vsl = VirtualSpaceList::vslist_nonclass();
207 assert(vsl != NULL, "Sanity");
208 vsl->verify(slow);
209 }
210
211 }
212 }
213 #endif
214
215 ////////////////////////////////7
216 // MetaspaceGC methods
217
218 volatile size_t MetaspaceGC::_capacity_until_GC = 0;
219 uint MetaspaceGC::_shrink_factor = 0;
220 bool MetaspaceGC::_should_concurrent_collect = false;
221
222 // VM_CollectForMetadataAllocation is the vm operation used to GC.
223 // Within the VM operation after the GC the attempt to allocate the metadata
224 // should succeed. If the GC did not free enough space for the metaspace
225 // allocation, the HWM is increased so that another virtualspace will be
226 // allocated for the metadata. With perm gen the increase in the perm
227 // gen had bounds, MinMetaspaceExpansion and MaxMetaspaceExpansion. The
228 // metaspace policy uses those as the small and large steps for the HWM.
229 //
230 // After the GC the compute_new_size() for MetaspaceGC is called to
231 // resize the capacity of the metaspaces. The current implementation
232 // is based on the flags MinMetaspaceFreeRatio and MaxMetaspaceFreeRatio used
233 // to resize the Java heap by some GC's. New flags can be implemented
234 // if really needed. MinMetaspaceFreeRatio is used to calculate how much
235 // free space is desirable in the metaspace capacity to decide how much
236 // to increase the HWM. MaxMetaspaceFreeRatio is used to decide how much
237 // free space is desirable in the metaspace capacity before decreasing
238 // the HWM.
239
240 // Calculate the amount to increase the high water mark (HWM).
241 // Increase by a minimum amount (MinMetaspaceExpansion) so that
319 size_t MetaspaceGC::dec_capacity_until_GC(size_t v) {
320 assert_is_aligned(v, Metaspace::commit_alignment());
321
322 return Atomic::sub(v, &_capacity_until_GC);
323 }
324
325 void MetaspaceGC::initialize() {
326 // Set the high-water mark to MaxMetapaceSize during VM initializaton since
327 // we can't do a GC during initialization.
328 _capacity_until_GC = MaxMetaspaceSize;
329 }
330
331 void MetaspaceGC::post_initialize() {
332 // Reset the high-water mark once the VM initialization is done.
333 _capacity_until_GC = MAX2(MetaspaceUtils::committed_bytes(), MetaspaceSize);
334 }
335
336 bool MetaspaceGC::can_expand(size_t word_size, bool is_class) {
337 // Check if the compressed class space is full.
338 if (is_class && Metaspace::using_class_space()) {
339 size_t class_committed = MetaspaceUtils::committed_bytes(metaspace::ClassType);
340 if (class_committed + word_size * BytesPerWord > CompressedClassSpaceSize) {
341 log_trace(gc, metaspace, freelist)("Cannot expand %s metaspace by " SIZE_FORMAT " words (CompressedClassSpaceSize = " SIZE_FORMAT " words)",
342 (is_class ? "class" : "non-class"), word_size, CompressedClassSpaceSize / sizeof(MetaWord));
343 return false;
344 }
345 }
346
347 // Check if the user has imposed a limit on the metaspace memory.
348 size_t committed_bytes = MetaspaceUtils::committed_bytes();
349 if (committed_bytes + word_size * BytesPerWord > MaxMetaspaceSize) {
350 log_trace(gc, metaspace, freelist)("Cannot expand %s metaspace by " SIZE_FORMAT " words (MaxMetaspaceSize = " SIZE_FORMAT " words)",
351 (is_class ? "class" : "non-class"), word_size, MaxMetaspaceSize / sizeof(MetaWord));
352 return false;
353 }
354
355 return true;
356 }
357
358 size_t MetaspaceGC::allowed_expansion() {
359 size_t committed_bytes = MetaspaceUtils::committed_bytes();
473 } else {
474 _shrink_factor = MIN2(current_shrink_factor * 4, (uint) 100);
475 }
476 log_trace(gc, metaspace)(" shrinking: initThreshold: %.1fK maximum_desired_capacity: %.1fK",
477 MetaspaceSize / (double) K, maximum_desired_capacity / (double) K);
478 log_trace(gc, metaspace)(" shrink_bytes: %.1fK current_shrink_factor: %d new shrink factor: %d MinMetaspaceExpansion: %.1fK",
479 shrink_bytes / (double) K, current_shrink_factor, _shrink_factor, MinMetaspaceExpansion / (double) K);
480 }
481 }
482
483 // Don't shrink unless it's significant
484 if (shrink_bytes >= MinMetaspaceExpansion &&
485 ((capacity_until_GC - shrink_bytes) >= MetaspaceSize)) {
486 size_t new_capacity_until_GC = MetaspaceGC::dec_capacity_until_GC(shrink_bytes);
487 Metaspace::tracer()->report_gc_threshold(capacity_until_GC,
488 new_capacity_until_GC,
489 MetaspaceGCThresholdUpdater::ComputeNewSize);
490 }
491 }
492
493
494
495 ////// Metaspace methods /////
496
497
498
499 MetaWord* Metaspace::_compressed_class_space_base = NULL;
500 size_t Metaspace::_compressed_class_space_size = 0;
501 const MetaspaceTracer* Metaspace::_tracer = NULL;
502 bool Metaspace::_initialized = false;
503 size_t Metaspace::_commit_alignment = 0;
504 size_t Metaspace::_reserve_alignment = 0;
505
506 DEBUG_ONLY(bool Metaspace::_frozen = false;)
507
508
509 #ifdef _LP64
510 static const uint64_t UnscaledClassSpaceMax = (uint64_t(max_juint) + 1);
511
512 void Metaspace::set_narrow_klass_base_and_shift(address metaspace_base, address cds_base) {
513 assert(!DumpSharedSpaces, "narrow_klass is set by MetaspaceShared class.");
514 // Figure out the narrow_klass_base and the narrow_klass_shift. The
515 // narrow_klass_base is the lower of the metaspace base and the cds base
516 // (if cds is enabled). The narrow_klass_shift depends on the distance
517 // between the lower base and higher address.
518 address lower_base;
519 address higher_address;
520 #if INCLUDE_CDS
521 if (UseSharedSpaces) {
522 higher_address = MAX2((address)(cds_base + MetaspaceShared::core_spaces_size()),
523 (address)(metaspace_base + compressed_class_space_size()));
524 lower_base = MIN2(metaspace_base, cds_base);
525 } else
526 #endif
527 {
563 (address)(metaspace_base + compressed_class_space_size()));
564 return ((uint64_t)(higher_address - lower_base) <= UnscaledClassSpaceMax);
565 }
566 #endif
567
568 // Try to allocate the metaspace at the requested addr.
569 void Metaspace::allocate_metaspace_compressed_klass_ptrs(char* requested_addr, address cds_base) {
570 assert(!DumpSharedSpaces, "compress klass space is allocated by MetaspaceShared class.");
571 assert(using_class_space(), "called improperly");
572 assert(UseCompressedClassPointers, "Only use with CompressedKlassPtrs");
573 assert(compressed_class_space_size() < KlassEncodingMetaspaceMax,
574 "Metaspace size is too big");
575 assert_is_aligned(requested_addr, _reserve_alignment);
576 assert_is_aligned(cds_base, _reserve_alignment);
577 assert_is_aligned(compressed_class_space_size(), _reserve_alignment);
578
579 // Don't use large pages for the class space.
580 bool large_pages = false;
581
582 #if !(defined(AARCH64) || defined(AIX))
583 ReservedSpace rs = ReservedSpace(compressed_class_space_size(),
584 _reserve_alignment,
585 large_pages,
586 requested_addr);
587 #else // AARCH64
588 ReservedSpace rs;
589
590 // Our compressed klass pointers may fit nicely into the lower 32
591 // bits.
592 if ((uint64_t)requested_addr + compressed_class_space_size() < 4*G) {
593 rs = ReservedSpace(compressed_class_space_size(),
594 _reserve_alignment,
595 large_pages,
596 requested_addr);
597 }
598
599 if (! rs.is_reserved()) {
600 // Aarch64: Try to align metaspace so that we can decode a compressed
601 // klass with a single MOVK instruction. We can do this iff the
602 // compressed class base is a multiple of 4G.
603 // Aix: Search for a place where we can find memory. If we need to load
604 // the base, 4G alignment is helpful, too.
605 size_t increment = AARCH64_ONLY(4*)G;
606 for (char *a = align_up(requested_addr, increment);
607 a < (char*)(1024*G);
608 a += increment) {
609 if (a == (char *)(32*G)) {
610 // Go faster from here on. Zero-based is no longer possible.
611 increment = 4*G;
612 }
613
614 #if INCLUDE_CDS
615 if (UseSharedSpaces
616 && ! can_use_cds_with_metaspace_addr(a, cds_base)) {
617 // We failed to find an aligned base that will reach. Fall
618 // back to using our requested addr.
619 rs = ReservedSpace(compressed_class_space_size(),
620 _reserve_alignment,
621 large_pages,
622 requested_addr);
623 break;
624 }
625 #endif
626
627 rs = ReservedSpace(compressed_class_space_size(),
628 _reserve_alignment,
629 large_pages,
630 a);
631 if (rs.is_reserved())
632 break;
633 }
634 }
635
636 #endif // AARCH64
637
638 if (!rs.is_reserved()) {
639 #if INCLUDE_CDS
640 if (UseSharedSpaces) {
641 size_t increment = align_up(1*G, _reserve_alignment);
642
643 // Keep trying to allocate the metaspace, increasing the requested_addr
644 // by 1GB each time, until we reach an address that will no longer allow
645 // use of CDS with compressed klass pointers.
646 char *addr = requested_addr;
647 while (!rs.is_reserved() && (addr + increment > addr) &&
648 can_use_cds_with_metaspace_addr(addr + increment, cds_base)) {
649 addr = addr + increment;
650 rs = ReservedSpace(compressed_class_space_size(),
651 _reserve_alignment, large_pages, addr);
652 }
653 }
654 #endif
655 // If no successful allocation then try to allocate the space anywhere. If
656 // that fails then OOM doom. At this point we cannot try allocating the
657 // metaspace as if UseCompressedClassPointers is off because too much
658 // initialization has happened that depends on UseCompressedClassPointers.
659 // So, UseCompressedClassPointers cannot be turned off at this point.
660 if (!rs.is_reserved()) {
661 rs = ReservedSpace(compressed_class_space_size(),
662 _reserve_alignment, large_pages);
663 if (!rs.is_reserved()) {
664 vm_exit_during_initialization(err_msg("Could not allocate metaspace: " SIZE_FORMAT " bytes",
665 compressed_class_space_size()));
666 }
667 }
668 }
669
670 // If we got here then the metaspace got allocated.
671 MemTracker::record_virtual_memory_type((address)rs.base(), mtClass);
672
673 _compressed_class_space_base = (MetaWord*)rs.base();
674
675 #if INCLUDE_CDS
676 // Verify that we can use shared spaces. Otherwise, turn off CDS.
677 if (UseSharedSpaces && !can_use_cds_with_metaspace_addr(rs.base(), cds_base)) {
678 FileMapInfo::stop_sharing_and_unmap(
679 "Could not allocate metaspace at a compatible address");
680 }
681 #endif
682 set_narrow_klass_base_and_shift((address)rs.base(),
683 UseSharedSpaces ? (address)cds_base : 0);
684
685 initialize_class_space(rs);
686
687 LogTarget(Trace, gc, metaspace) lt;
688 if (lt.is_enabled()) {
689 ResourceMark rm;
690 LogStream ls(lt);
691 print_compressed_class_space(&ls, requested_addr);
692 }
693 }
694
695 // For UseCompressedClassPointers the class space is reserved above the top of
696 // the Java heap. The argument passed in is at the base of the compressed space.
697 void Metaspace::initialize_class_space(ReservedSpace rs) {
698
699 // The reserved space size may be bigger because of alignment, esp with UseLargePages
700 assert(rs.size() >= CompressedClassSpaceSize,
701 SIZE_FORMAT " != " SIZE_FORMAT, rs.size(), CompressedClassSpaceSize);
702 assert(using_class_space(), "Must be using class space");
703
704 VirtualSpaceList* vsl = new VirtualSpaceList("class space list", rs, CommitLimiter::globalLimiter());
705 VirtualSpaceList::set_vslist_class(vsl);
706 ChunkManager* cm = new ChunkManager("class space chunk manager", vsl);
707 ChunkManager::set_chunkmanager_class(cm);
708
709 }
710
711
712 void Metaspace::print_compressed_class_space(outputStream* st, const char* requested_addr) {
713 st->print_cr("Narrow klass base: " PTR_FORMAT ", Narrow klass shift: %d",
714 p2i(CompressedKlassPointers::base()), CompressedKlassPointers::shift());
715 if (Metaspace::using_class_space()) {
716 st->print("Compressed class space size: " SIZE_FORMAT " Address: " PTR_FORMAT,
717 compressed_class_space_size(), p2i(compressed_class_space_base()));
718 if (requested_addr != 0) {
719 st->print(" Req Addr: " PTR_FORMAT, p2i(requested_addr));
720 }
721 st->cr();
722 }
723 }
724
725 #endif
726
727 void Metaspace::ergo_initialize() {
728 if (DumpSharedSpaces) {
729 // Using large pages when dumping the shared archive is currently not implemented.
730 FLAG_SET_ERGO(UseLargePagesInMetaspace, false);
731 }
732
733 size_t page_size = os::vm_page_size();
734 if (UseLargePages && UseLargePagesInMetaspace) {
735 page_size = os::large_page_size();
736 }
737
738 // Commit alignment: (I would rather hide this since this is an implementation detail but we need it
739 // when calculating the gc threshold).
740 _commit_alignment = metaspace::constants::commit_granule_bytes;
741
742 // Reserve alignment: all Metaspace memory mappings are to be aligned to the size of a root chunk.
743 _reserve_alignment = MAX2(page_size, (size_t)metaspace::chklvl::MAX_CHUNK_BYTE_SIZE);
744
745 assert(is_aligned(_reserve_alignment, os::vm_allocation_granularity()),
746 "root chunk size must be a multiple of alloc granularity");
747
748 // Do not use FLAG_SET_ERGO to update MaxMetaspaceSize, since this will
749 // override if MaxMetaspaceSize was set on the command line or not.
750 // This information is needed later to conform to the specification of the
751 // java.lang.management.MemoryUsage API.
752 //
753 // Ideally, we would be able to set the default value of MaxMetaspaceSize in
754 // globals.hpp to the aligned value, but this is not possible, since the
755 // alignment depends on other flags being parsed.
756 MaxMetaspaceSize = align_down_bounded(MaxMetaspaceSize, _reserve_alignment);
757
758 if (MetaspaceSize > MaxMetaspaceSize) {
759 MetaspaceSize = MaxMetaspaceSize;
760 }
761
762 MetaspaceSize = align_down_bounded(MetaspaceSize, _commit_alignment);
763
764 assert(MetaspaceSize <= MaxMetaspaceSize, "MetaspaceSize should be limited by MaxMetaspaceSize");
765
766 MinMetaspaceExpansion = align_down_bounded(MinMetaspaceExpansion, _commit_alignment);
767 MaxMetaspaceExpansion = align_down_bounded(MaxMetaspaceExpansion, _commit_alignment);
768
769 CompressedClassSpaceSize = align_down_bounded(CompressedClassSpaceSize, _reserve_alignment);
770
771 // Note: InitialBootClassLoaderMetaspaceSize is an old parameter which is used to determine the chunk size
772 // of the first non-class chunk handed to the boot class loader. See metaspace/chunkAllocSequence.hpp.
773 size_t min_metaspace_sz = align_up(InitialBootClassLoaderMetaspaceSize, _reserve_alignment);
774 if (UseCompressedClassPointers) {
775 if (min_metaspace_sz >= MaxMetaspaceSize) {
776 vm_exit_during_initialization("MaxMetaspaceSize is too small.");
777 } else if ((min_metaspace_sz + CompressedClassSpaceSize) > MaxMetaspaceSize) {
778 FLAG_SET_ERGO(CompressedClassSpaceSize, MaxMetaspaceSize - min_metaspace_sz);
779 }
780 } else if (min_metaspace_sz >= MaxMetaspaceSize) {
781 FLAG_SET_ERGO(InitialBootClassLoaderMetaspaceSize,
782 min_metaspace_sz);
783 }
784
785 _compressed_class_space_size = CompressedClassSpaceSize;
786 }
787
788 void Metaspace::global_initialize() {
789 MetaspaceGC::initialize(); // <- since we do not prealloc init chunks anymore is this still needed?
790
791 #if INCLUDE_CDS
792 if (DumpSharedSpaces) {
793 MetaspaceShared::initialize_dumptime_shared_and_meta_spaces();
794 } else if (UseSharedSpaces) {
795 // If any of the archived space fails to map, UseSharedSpaces
796 // is reset to false. Fall through to the
797 // (!DumpSharedSpaces && !UseSharedSpaces) case to set up class
798 // metaspace.
799 MetaspaceShared::initialize_runtime_shared_and_meta_spaces();
800 }
801
802 if (DynamicDumpSharedSpaces && !UseSharedSpaces) {
803 vm_exit_during_initialization("DynamicDumpSharedSpaces is unsupported when base CDS archive is not loaded", NULL);
804 }
805 #endif // INCLUDE_CDS
806
807 // Initialize class space:
808 if (CDS_ONLY(!DumpSharedSpaces && !UseSharedSpaces) NOT_CDS(true)) {
809 #ifdef _LP64
810 if (using_class_space()) {
811 char* base = (char*)align_up(Universe::heap()->reserved_region().end(), _reserve_alignment);
812 allocate_metaspace_compressed_klass_ptrs(base, 0);
813 }
814 #endif // _LP64
815 }
816
817 // Initialize non-class virtual space list, and its chunk manager:
818 VirtualSpaceList* vsl = new VirtualSpaceList("Non-Class VirtualSpaceList", CommitLimiter::globalLimiter());
819 VirtualSpaceList::set_vslist_nonclass(vsl);
820 ChunkManager* cm = new ChunkManager("Non-Class ChunkManager", vsl);
821 ChunkManager::set_chunkmanager_nonclass(cm);
822
823 _tracer = new MetaspaceTracer();
824
825 _initialized = true;
826
827 }
828
829 void Metaspace::post_initialize() {
830 // TODO do we really need this? Metaspace should not be allocated during VM initialization.
831 assert(RunningCounters::committed_words() == 0, "CHECKECHK");
832 MetaspaceGC::post_initialize();
833 }
834
835 MetaWord* Metaspace::allocate(ClassLoaderData* loader_data, size_t word_size,
836 MetaspaceObj::Type type, TRAPS) {
837 assert(!_frozen, "sanity");
838 assert(!(DumpSharedSpaces && THREAD->is_VM_thread()), "sanity");
839
840 if (HAS_PENDING_EXCEPTION) {
841 assert(false, "Should not allocate with exception pending");
842 return NULL; // caller does a CHECK_NULL too
843 }
844
845 assert(loader_data != NULL, "Should never pass around a NULL loader_data. "
846 "ClassLoaderData::the_null_class_loader_data() should have been used.");
847
848 MetadataType mdtype = (type == MetaspaceObj::ClassType) ? metaspace::ClassType : metaspace::NonClassType;
849
850 // Try to allocate metadata.
851 MetaWord* result = loader_data->metaspace_non_null()->allocate(word_size, mdtype);
852
853 if (result == NULL) {
854 tracer()->report_metaspace_allocation_failure(loader_data, word_size, type, mdtype);
855
856 // Allocation failed.
857 if (is_init_completed()) {
858 // Only start a GC if the bootstrapping has completed.
859 // Try to clean out some heap memory and retry. This can prevent premature
860 // expansion of the metaspace.
861 result = Universe::heap()->satisfy_failed_metadata_allocation(loader_data, word_size, mdtype);
862 }
863 }
864
865 if (result == NULL) {
866 if (DumpSharedSpaces) {
867 // CDS dumping keeps loading classes, so if we hit an OOM we probably will keep hitting OOM.
868 // We should abort to avoid generating a potentially bad archive.
871 err_msg("Please increase MaxMetaspaceSize (currently " SIZE_FORMAT " bytes).", MaxMetaspaceSize));
872 }
873 report_metadata_oome(loader_data, word_size, type, mdtype, THREAD);
874 assert(HAS_PENDING_EXCEPTION, "sanity");
875 return NULL;
876 }
877
878 // Zero initialize.
879 Copy::fill_to_words((HeapWord*)result, word_size, 0);
880
881 return result;
882 }
883
884 void Metaspace::report_metadata_oome(ClassLoaderData* loader_data, size_t word_size, MetaspaceObj::Type type, MetadataType mdtype, TRAPS) {
885 tracer()->report_metadata_oom(loader_data, word_size, type, mdtype);
886
887 // If result is still null, we are out of memory.
888 Log(gc, metaspace, freelist, oom) log;
889 if (log.is_info()) {
890 log.info("Metaspace (%s) allocation failed for size " SIZE_FORMAT,
891 is_class(mdtype) ? "class" : "data", word_size);
892 ResourceMark rm;
893 if (log.is_debug()) {
894 if (loader_data->metaspace_or_null() != NULL) {
895 LogStream ls(log.debug());
896 loader_data->print_value_on(&ls);
897 }
898 }
899 LogStream ls(log.info());
900 // In case of an OOM, log out a short but still useful report.
901 MetaspaceUtils::print_basic_report(&ls, 0);
902 }
903
904 // Which limit did we hit? CompressedClassSpaceSize or MaxMetaspaceSize?
905 bool out_of_compressed_class_space = false;
906 if (is_class(mdtype)) {
907 ClassLoaderMetaspace* metaspace = loader_data->metaspace_non_null();
908 out_of_compressed_class_space =
909 MetaspaceUtils::committed_bytes(metaspace::ClassType) +
910 // TODO: Okay this is just cheesy.
911 // Of course this may fail and return incorrect results.
912 // Think this over - we need some clean way to remember which limit
913 // exactly we hit during an allocation. Some sort of allocation context structure?
914 align_up(word_size * BytesPerWord, 4 * M) >
915 CompressedClassSpaceSize;
916 }
917
918 // -XX:+HeapDumpOnOutOfMemoryError and -XX:OnOutOfMemoryError support
919 const char* space_string = out_of_compressed_class_space ?
920 "Compressed class space" : "Metaspace";
921
922 report_java_out_of_memory(space_string);
923
924 if (JvmtiExport::should_post_resource_exhausted()) {
925 JvmtiExport::post_resource_exhausted(
926 JVMTI_RESOURCE_EXHAUSTED_OOM_ERROR,
927 space_string);
928 }
929
930 if (!is_init_completed()) {
931 vm_exit_during_initialization("OutOfMemoryError", space_string);
932 }
933
934 if (out_of_compressed_class_space) {
935 THROW_OOP(Universe::out_of_memory_error_class_metaspace());
936 } else {
937 THROW_OOP(Universe::out_of_memory_error_metaspace());
938 }
939 }
940
941 void Metaspace::purge() {
942 // Todo
943 }
944
945 bool Metaspace::contains(const void* ptr) {
946 if (MetaspaceShared::is_in_shared_metaspace(ptr)) {
947 return true;
948 }
949 return contains_non_shared(ptr);
950 }
951
952 bool Metaspace::contains_non_shared(const void* ptr) {
953 if (using_class_space() && VirtualSpaceList::vslist_class()->contains((MetaWord*)ptr)) {
954 return true;
955 }
956
957 return VirtualSpaceList::vslist_nonclass()->contains((MetaWord*)ptr);
958 }
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