25 #if !defined(__clang_major__) && defined(__GNUC__)
26 #define ATTRIBUTE_PRINTF(x,y) // FIXME, formats are a mess.
27 #endif
28
29 #include "precompiled.hpp"
30 #include "code/codeCache.hpp"
31 #include "code/icBuffer.hpp"
32 #include "gc_implementation/g1/bufferingOopClosure.hpp"
33 #include "gc_implementation/g1/concurrentG1Refine.hpp"
34 #include "gc_implementation/g1/concurrentG1RefineThread.hpp"
35 #include "gc_implementation/g1/concurrentMarkThread.inline.hpp"
36 #include "gc_implementation/g1/g1AllocRegion.inline.hpp"
37 #include "gc_implementation/g1/g1CollectedHeap.inline.hpp"
38 #include "gc_implementation/g1/g1CollectorPolicy.hpp"
39 #include "gc_implementation/g1/g1ErgoVerbose.hpp"
40 #include "gc_implementation/g1/g1EvacFailure.hpp"
41 #include "gc_implementation/g1/g1GCPhaseTimes.hpp"
42 #include "gc_implementation/g1/g1Log.hpp"
43 #include "gc_implementation/g1/g1MarkSweep.hpp"
44 #include "gc_implementation/g1/g1OopClosures.inline.hpp"
45 #include "gc_implementation/g1/g1RemSet.inline.hpp"
46 #include "gc_implementation/g1/g1StringDedup.hpp"
47 #include "gc_implementation/g1/g1YCTypes.hpp"
48 #include "gc_implementation/g1/heapRegion.inline.hpp"
49 #include "gc_implementation/g1/heapRegionRemSet.hpp"
50 #include "gc_implementation/g1/heapRegionSeq.inline.hpp"
51 #include "gc_implementation/g1/vm_operations_g1.hpp"
52 #include "gc_implementation/shared/gcHeapSummary.hpp"
53 #include "gc_implementation/shared/gcTimer.hpp"
54 #include "gc_implementation/shared/gcTrace.hpp"
55 #include "gc_implementation/shared/gcTraceTime.hpp"
56 #include "gc_implementation/shared/isGCActiveMark.hpp"
57 #include "memory/gcLocker.inline.hpp"
58 #include "memory/generationSpec.hpp"
59 #include "memory/iterator.hpp"
60 #include "memory/referenceProcessor.hpp"
61 #include "oops/oop.inline.hpp"
62 #include "oops/oop.pcgc.inline.hpp"
63 #include "runtime/prefetch.inline.hpp"
64 #include "runtime/orderAccess.inline.hpp"
65 #include "runtime/vmThread.hpp"
66 #include "utilities/ticks.hpp"
67
68 size_t G1CollectedHeap::_humongous_object_threshold_in_words = 0;
69
70 // turn it on so that the contents of the young list (scan-only /
71 // to-be-collected) are printed at "strategic" points before / during
72 // / after the collection --- this is useful for debugging
73 #define YOUNG_LIST_VERBOSE 0
74 // CURRENT STATUS
75 // This file is under construction. Search for "FIXME".
76
77 // INVARIANTS/NOTES
78 //
79 // All allocation activity covered by the G1CollectedHeap interface is
80 // serialized by acquiring the HeapLock. This happens in mem_allocate
81 // and allocate_new_tlab, which are the "entry" points to the
82 // allocation code from the rest of the JVM. (Note that this does not
83 // apply to TLAB allocation, which is not part of this interface: it
84 // is done by clients of this interface.)
85
86 // Notes on implementation of parallelism in different tasks.
4551 } else {
4552 assert(purpose == GCAllocForTenured, "sanity");
4553 HeapWord* result = old_attempt_allocation(word_size);
4554 if (result != NULL) {
4555 return result;
4556 } else {
4557 // Let's try to allocate in the survivors in case we can fit the
4558 // object there.
4559 return survivor_attempt_allocation(word_size);
4560 }
4561 }
4562
4563 ShouldNotReachHere();
4564 // Trying to keep some compilers happy.
4565 return NULL;
4566 }
4567
4568 G1ParGCAllocBuffer::G1ParGCAllocBuffer(size_t gclab_word_size) :
4569 ParGCAllocBuffer(gclab_word_size), _retired(true) { }
4570
4571 G1ParScanThreadState::G1ParScanThreadState(G1CollectedHeap* g1h, uint queue_num, ReferenceProcessor* rp)
4572 : _g1h(g1h),
4573 _refs(g1h->task_queue(queue_num)),
4574 _dcq(&g1h->dirty_card_queue_set()),
4575 _ct_bs(g1h->g1_barrier_set()),
4576 _g1_rem(g1h->g1_rem_set()),
4577 _hash_seed(17), _queue_num(queue_num),
4578 _term_attempts(0),
4579 _surviving_alloc_buffer(g1h->desired_plab_sz(GCAllocForSurvived)),
4580 _tenured_alloc_buffer(g1h->desired_plab_sz(GCAllocForTenured)),
4581 _age_table(false), _scanner(g1h, this, rp),
4582 _strong_roots_time(0), _term_time(0),
4583 _alloc_buffer_waste(0), _undo_waste(0) {
4584 // we allocate G1YoungSurvRateNumRegions plus one entries, since
4585 // we "sacrifice" entry 0 to keep track of surviving bytes for
4586 // non-young regions (where the age is -1)
4587 // We also add a few elements at the beginning and at the end in
4588 // an attempt to eliminate cache contention
4589 uint real_length = 1 + _g1h->g1_policy()->young_cset_region_length();
4590 uint array_length = PADDING_ELEM_NUM +
4591 real_length +
4592 PADDING_ELEM_NUM;
4593 _surviving_young_words_base = NEW_C_HEAP_ARRAY(size_t, array_length, mtGC);
4594 if (_surviving_young_words_base == NULL)
4595 vm_exit_out_of_memory(array_length * sizeof(size_t), OOM_MALLOC_ERROR,
4596 "Not enough space for young surv histo.");
4597 _surviving_young_words = _surviving_young_words_base + PADDING_ELEM_NUM;
4598 memset(_surviving_young_words, 0, (size_t) real_length * sizeof(size_t));
4599
4600 _alloc_buffers[GCAllocForSurvived] = &_surviving_alloc_buffer;
4601 _alloc_buffers[GCAllocForTenured] = &_tenured_alloc_buffer;
4602
4603 _start = os::elapsedTime();
4604 }
4605
4606 void
4607 G1ParScanThreadState::print_termination_stats_hdr(outputStream* const st)
4608 {
4609 st->print_raw_cr("GC Termination Stats");
4610 st->print_raw_cr(" elapsed --strong roots-- -------termination-------"
4611 " ------waste (KiB)------");
4612 st->print_raw_cr("thr ms ms % ms % attempts"
4613 " total alloc undo");
4614 st->print_raw_cr("--- --------- --------- ------ --------- ------ --------"
4615 " ------- ------- -------");
4616 }
4617
4618 void
4619 G1ParScanThreadState::print_termination_stats(int i,
4620 outputStream* const st) const
4621 {
4622 const double elapsed_ms = elapsed_time() * 1000.0;
4623 const double s_roots_ms = strong_roots_time() * 1000.0;
4624 const double term_ms = term_time() * 1000.0;
4625 st->print_cr("%3d %9.2f %9.2f %6.2f "
4626 "%9.2f %6.2f " SIZE_FORMAT_W(8) " "
4627 SIZE_FORMAT_W(7) " " SIZE_FORMAT_W(7) " " SIZE_FORMAT_W(7),
4628 i, elapsed_ms, s_roots_ms, s_roots_ms * 100 / elapsed_ms,
4629 term_ms, term_ms * 100 / elapsed_ms, term_attempts(),
4630 (alloc_buffer_waste() + undo_waste()) * HeapWordSize / K,
4631 alloc_buffer_waste() * HeapWordSize / K,
4632 undo_waste() * HeapWordSize / K);
4633 }
4634
4635 #ifdef ASSERT
4636 bool G1ParScanThreadState::verify_ref(narrowOop* ref) const {
4637 assert(ref != NULL, "invariant");
4638 assert(UseCompressedOops, "sanity");
4639 assert(!has_partial_array_mask(ref), err_msg("ref=" PTR_FORMAT, ref));
4640 oop p = oopDesc::load_decode_heap_oop(ref);
4641 assert(_g1h->is_in_g1_reserved(p),
4642 err_msg("ref=" PTR_FORMAT " p=" PTR_FORMAT, ref, (void *)p));
4643 return true;
4644 }
4645
4646 bool G1ParScanThreadState::verify_ref(oop* ref) const {
4647 assert(ref != NULL, "invariant");
4648 if (has_partial_array_mask(ref)) {
4649 // Must be in the collection set--it's already been copied.
4650 oop p = clear_partial_array_mask(ref);
4651 assert(_g1h->obj_in_cs(p),
4652 err_msg("ref=" PTR_FORMAT " p=" PTR_FORMAT, ref, (void *)p));
4653 } else {
4654 oop p = oopDesc::load_decode_heap_oop(ref);
4655 assert(_g1h->is_in_g1_reserved(p),
4656 err_msg("ref=" PTR_FORMAT " p=" PTR_FORMAT, ref, (void *)p));
4657 }
4658 return true;
4659 }
4660
4661 bool G1ParScanThreadState::verify_task(StarTask ref) const {
4662 if (ref.is_narrow()) {
4663 return verify_ref((narrowOop*) ref);
4664 } else {
4665 return verify_ref((oop*) ref);
4666 }
4667 }
4668 #endif // ASSERT
4669
4670 void G1ParScanThreadState::trim_queue() {
4671 assert(_evac_failure_cl != NULL, "not set");
4672
4673 StarTask ref;
4674 do {
4675 // Drain the overflow stack first, so other threads can steal.
4676 while (refs()->pop_overflow(ref)) {
4677 deal_with_reference(ref);
4678 }
4679
4680 while (refs()->pop_local(ref)) {
4681 deal_with_reference(ref);
4682 }
4683 } while (!refs()->is_empty());
4684 }
4685
4686 G1ParClosureSuper::G1ParClosureSuper(G1CollectedHeap* g1,
4687 G1ParScanThreadState* par_scan_state) :
4688 _g1(g1), _par_scan_state(par_scan_state),
4689 _worker_id(par_scan_state->queue_num()) { }
4690
4691 void G1ParCopyHelper::mark_object(oop obj) {
4692 #ifdef ASSERT
4693 HeapRegion* hr = _g1->heap_region_containing(obj);
4694 assert(hr != NULL, "sanity");
4695 assert(!hr->in_collection_set(), "should not mark objects in the CSet");
4696 #endif // ASSERT
4697
4698 // We know that the object is not moving so it's safe to read its size.
4699 _cm->grayRoot(obj, (size_t) obj->size(), _worker_id);
4700 }
4701
4702 void G1ParCopyHelper::mark_forwarded_object(oop from_obj, oop to_obj) {
4703 #ifdef ASSERT
4704 assert(from_obj->is_forwarded(), "from obj should be forwarded");
4705 assert(from_obj->forwardee() == to_obj, "to obj should be the forwardee");
4706 assert(from_obj != to_obj, "should not be self-forwarded");
4707
4708 HeapRegion* from_hr = _g1->heap_region_containing(from_obj);
4709 assert(from_hr != NULL, "sanity");
4710 assert(from_hr->in_collection_set(), "from obj should be in the CSet");
4711
4712 HeapRegion* to_hr = _g1->heap_region_containing(to_obj);
4713 assert(to_hr != NULL, "sanity");
4714 assert(!to_hr->in_collection_set(), "should not mark objects in the CSet");
4715 #endif // ASSERT
4716
4717 // The object might be in the process of being copied by another
4718 // worker so we cannot trust that its to-space image is
4719 // well-formed. So we have to read its size from its from-space
4720 // image which we know should not be changing.
4721 _cm->grayRoot(to_obj, (size_t) from_obj->size(), _worker_id);
4722 }
4723
4724 oop G1ParScanThreadState::copy_to_survivor_space(oop const old) {
4725 size_t word_sz = old->size();
4726 HeapRegion* from_region = _g1h->heap_region_containing_raw(old);
4727 // +1 to make the -1 indexes valid...
4728 int young_index = from_region->young_index_in_cset()+1;
4729 assert( (from_region->is_young() && young_index > 0) ||
4730 (!from_region->is_young() && young_index == 0), "invariant" );
4731 G1CollectorPolicy* g1p = _g1h->g1_policy();
4732 markOop m = old->mark();
4733 int age = m->has_displaced_mark_helper() ? m->displaced_mark_helper()->age()
4734 : m->age();
4735 GCAllocPurpose alloc_purpose = g1p->evacuation_destination(from_region, age,
4736 word_sz);
4737 HeapWord* obj_ptr = allocate(alloc_purpose, word_sz);
4738 #ifndef PRODUCT
4739 // Should this evacuation fail?
4740 if (_g1h->evacuation_should_fail()) {
4741 if (obj_ptr != NULL) {
4742 undo_allocation(alloc_purpose, obj_ptr, word_sz);
4743 obj_ptr = NULL;
4744 }
4745 }
4746 #endif // !PRODUCT
4747
4748 if (obj_ptr == NULL) {
4749 // This will either forward-to-self, or detect that someone else has
4750 // installed a forwarding pointer.
4751 return _g1h->handle_evacuation_failure_par(this, old);
4752 }
4753
4754 oop obj = oop(obj_ptr);
4755
4756 // We're going to allocate linearly, so might as well prefetch ahead.
4757 Prefetch::write(obj_ptr, PrefetchCopyIntervalInBytes);
4758
4759 oop forward_ptr = old->forward_to_atomic(obj);
4760 if (forward_ptr == NULL) {
4761 Copy::aligned_disjoint_words((HeapWord*) old, obj_ptr, word_sz);
4762
4763 // alloc_purpose is just a hint to allocate() above, recheck the type of region
4764 // we actually allocated from and update alloc_purpose accordingly
4765 HeapRegion* to_region = _g1h->heap_region_containing_raw(obj_ptr);
4766 alloc_purpose = to_region->is_young() ? GCAllocForSurvived : GCAllocForTenured;
4767
4768 if (g1p->track_object_age(alloc_purpose)) {
4769 // We could simply do obj->incr_age(). However, this causes a
4770 // performance issue. obj->incr_age() will first check whether
4771 // the object has a displaced mark by checking its mark word;
4772 // getting the mark word from the new location of the object
4773 // stalls. So, given that we already have the mark word and we
4774 // are about to install it anyway, it's better to increase the
4775 // age on the mark word, when the object does not have a
4776 // displaced mark word. We're not expecting many objects to have
4777 // a displaced marked word, so that case is not optimized
4778 // further (it could be...) and we simply call obj->incr_age().
4779
4780 if (m->has_displaced_mark_helper()) {
4781 // in this case, we have to install the mark word first,
4782 // otherwise obj looks to be forwarded (the old mark word,
4783 // which contains the forward pointer, was copied)
4784 obj->set_mark(m);
4785 obj->incr_age();
4786 } else {
4787 m = m->incr_age();
4788 obj->set_mark(m);
4789 }
4790 age_table()->add(obj, word_sz);
4791 } else {
4792 obj->set_mark(m);
4793 }
4794
4795 if (G1StringDedup::is_enabled()) {
4796 G1StringDedup::enqueue_from_evacuation(from_region->is_young(),
4797 to_region->is_young(),
4798 queue_num(),
4799 obj);
4800 }
4801
4802 size_t* surv_young_words = surviving_young_words();
4803 surv_young_words[young_index] += word_sz;
4804
4805 if (obj->is_objArray() && arrayOop(obj)->length() >= ParGCArrayScanChunk) {
4806 // We keep track of the next start index in the length field of
4807 // the to-space object. The actual length can be found in the
4808 // length field of the from-space object.
4809 arrayOop(obj)->set_length(0);
4810 oop* old_p = set_partial_array_mask(old);
4811 push_on_queue(old_p);
4812 } else {
4813 // No point in using the slower heap_region_containing() method,
4814 // given that we know obj is in the heap.
4815 _scanner.set_region(_g1h->heap_region_containing_raw(obj));
4816 obj->oop_iterate_backwards(&_scanner);
4817 }
4818 } else {
4819 undo_allocation(alloc_purpose, obj_ptr, word_sz);
4820 obj = forward_ptr;
4821 }
4822 return obj;
4823 }
4824
4825 template <class T>
4826 void G1ParCopyHelper::do_klass_barrier(T* p, oop new_obj) {
4827 if (_g1->heap_region_containing_raw(new_obj)->is_young()) {
4828 _scanned_klass->record_modified_oops();
4829 }
4830 }
4831
4832 template <G1Barrier barrier, bool do_mark_object>
4833 template <class T>
4834 void G1ParCopyClosure<barrier, do_mark_object>::do_oop_work(T* p) {
4835 T heap_oop = oopDesc::load_heap_oop(p);
4836
4837 if (oopDesc::is_null(heap_oop)) {
4838 return;
4839 }
4840
4841 oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
4842
4843 assert(_worker_id == _par_scan_state->queue_num(), "sanity");
4844
|
25 #if !defined(__clang_major__) && defined(__GNUC__)
26 #define ATTRIBUTE_PRINTF(x,y) // FIXME, formats are a mess.
27 #endif
28
29 #include "precompiled.hpp"
30 #include "code/codeCache.hpp"
31 #include "code/icBuffer.hpp"
32 #include "gc_implementation/g1/bufferingOopClosure.hpp"
33 #include "gc_implementation/g1/concurrentG1Refine.hpp"
34 #include "gc_implementation/g1/concurrentG1RefineThread.hpp"
35 #include "gc_implementation/g1/concurrentMarkThread.inline.hpp"
36 #include "gc_implementation/g1/g1AllocRegion.inline.hpp"
37 #include "gc_implementation/g1/g1CollectedHeap.inline.hpp"
38 #include "gc_implementation/g1/g1CollectorPolicy.hpp"
39 #include "gc_implementation/g1/g1ErgoVerbose.hpp"
40 #include "gc_implementation/g1/g1EvacFailure.hpp"
41 #include "gc_implementation/g1/g1GCPhaseTimes.hpp"
42 #include "gc_implementation/g1/g1Log.hpp"
43 #include "gc_implementation/g1/g1MarkSweep.hpp"
44 #include "gc_implementation/g1/g1OopClosures.inline.hpp"
45 #include "gc_implementation/g1/g1ParScanThreadState.inline.hpp"
46 #include "gc_implementation/g1/g1RemSet.inline.hpp"
47 #include "gc_implementation/g1/g1StringDedup.hpp"
48 #include "gc_implementation/g1/g1YCTypes.hpp"
49 #include "gc_implementation/g1/heapRegion.inline.hpp"
50 #include "gc_implementation/g1/heapRegionRemSet.hpp"
51 #include "gc_implementation/g1/heapRegionSeq.inline.hpp"
52 #include "gc_implementation/g1/vm_operations_g1.hpp"
53 #include "gc_implementation/shared/gcHeapSummary.hpp"
54 #include "gc_implementation/shared/gcTimer.hpp"
55 #include "gc_implementation/shared/gcTrace.hpp"
56 #include "gc_implementation/shared/gcTraceTime.hpp"
57 #include "gc_implementation/shared/isGCActiveMark.hpp"
58 #include "memory/gcLocker.inline.hpp"
59 #include "memory/generationSpec.hpp"
60 #include "memory/iterator.hpp"
61 #include "memory/referenceProcessor.hpp"
62 #include "oops/oop.inline.hpp"
63 #include "oops/oop.pcgc.inline.hpp"
64 #include "runtime/orderAccess.inline.hpp"
65 #include "runtime/vmThread.hpp"
66
67 size_t G1CollectedHeap::_humongous_object_threshold_in_words = 0;
68
69 // turn it on so that the contents of the young list (scan-only /
70 // to-be-collected) are printed at "strategic" points before / during
71 // / after the collection --- this is useful for debugging
72 #define YOUNG_LIST_VERBOSE 0
73 // CURRENT STATUS
74 // This file is under construction. Search for "FIXME".
75
76 // INVARIANTS/NOTES
77 //
78 // All allocation activity covered by the G1CollectedHeap interface is
79 // serialized by acquiring the HeapLock. This happens in mem_allocate
80 // and allocate_new_tlab, which are the "entry" points to the
81 // allocation code from the rest of the JVM. (Note that this does not
82 // apply to TLAB allocation, which is not part of this interface: it
83 // is done by clients of this interface.)
84
85 // Notes on implementation of parallelism in different tasks.
4550 } else {
4551 assert(purpose == GCAllocForTenured, "sanity");
4552 HeapWord* result = old_attempt_allocation(word_size);
4553 if (result != NULL) {
4554 return result;
4555 } else {
4556 // Let's try to allocate in the survivors in case we can fit the
4557 // object there.
4558 return survivor_attempt_allocation(word_size);
4559 }
4560 }
4561
4562 ShouldNotReachHere();
4563 // Trying to keep some compilers happy.
4564 return NULL;
4565 }
4566
4567 G1ParGCAllocBuffer::G1ParGCAllocBuffer(size_t gclab_word_size) :
4568 ParGCAllocBuffer(gclab_word_size), _retired(true) { }
4569
4570 void G1ParCopyHelper::mark_object(oop obj) {
4571 #ifdef ASSERT
4572 HeapRegion* hr = _g1->heap_region_containing(obj);
4573 assert(hr != NULL, "sanity");
4574 assert(!hr->in_collection_set(), "should not mark objects in the CSet");
4575 #endif // ASSERT
4576
4577 // We know that the object is not moving so it's safe to read its size.
4578 _cm->grayRoot(obj, (size_t) obj->size(), _worker_id);
4579 }
4580
4581 void G1ParCopyHelper::mark_forwarded_object(oop from_obj, oop to_obj) {
4582 #ifdef ASSERT
4583 assert(from_obj->is_forwarded(), "from obj should be forwarded");
4584 assert(from_obj->forwardee() == to_obj, "to obj should be the forwardee");
4585 assert(from_obj != to_obj, "should not be self-forwarded");
4586
4587 HeapRegion* from_hr = _g1->heap_region_containing(from_obj);
4588 assert(from_hr != NULL, "sanity");
4589 assert(from_hr->in_collection_set(), "from obj should be in the CSet");
4590
4591 HeapRegion* to_hr = _g1->heap_region_containing(to_obj);
4592 assert(to_hr != NULL, "sanity");
4593 assert(!to_hr->in_collection_set(), "should not mark objects in the CSet");
4594 #endif // ASSERT
4595
4596 // The object might be in the process of being copied by another
4597 // worker so we cannot trust that its to-space image is
4598 // well-formed. So we have to read its size from its from-space
4599 // image which we know should not be changing.
4600 _cm->grayRoot(to_obj, (size_t) from_obj->size(), _worker_id);
4601 }
4602
4603 template <class T>
4604 void G1ParCopyHelper::do_klass_barrier(T* p, oop new_obj) {
4605 if (_g1->heap_region_containing_raw(new_obj)->is_young()) {
4606 _scanned_klass->record_modified_oops();
4607 }
4608 }
4609
4610 template <G1Barrier barrier, bool do_mark_object>
4611 template <class T>
4612 void G1ParCopyClosure<barrier, do_mark_object>::do_oop_work(T* p) {
4613 T heap_oop = oopDesc::load_heap_oop(p);
4614
4615 if (oopDesc::is_null(heap_oop)) {
4616 return;
4617 }
4618
4619 oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
4620
4621 assert(_worker_id == _par_scan_state->queue_num(), "sanity");
4622
|