355
356 _verifier->check_bitmaps("Humongous Region Allocation", first_hr);
357
358 assert(words_not_fillable == 0 ||
359 first_hr->bottom() + word_size_sum - words_not_fillable == hr->top(),
360 "Miscalculation in humongous allocation");
361
362 increase_used((word_size_sum - words_not_fillable) * HeapWordSize);
363
364 for (uint i = first; i <= last; ++i) {
365 hr = region_at(i);
366 _humongous_set.add(hr);
367 _hr_printer.alloc(hr);
368 }
369
370 return new_obj;
371 }
372
373 size_t G1CollectedHeap::humongous_obj_size_in_regions(size_t word_size) {
374 assert(is_humongous(word_size), "Object of size " SIZE_FORMAT " must be humongous here", word_size);
375 return align_size_up_(word_size, HeapRegion::GrainWords) / HeapRegion::GrainWords;
376 }
377
378 // If could fit into free regions w/o expansion, try.
379 // Otherwise, if can expand, do so.
380 // Otherwise, if using ex regions might help, try with ex given back.
381 HeapWord* G1CollectedHeap::humongous_obj_allocate(size_t word_size, AllocationContext_t context) {
382 assert_heap_locked_or_at_safepoint(true /* should_be_vm_thread */);
383
384 _verifier->verify_region_sets_optional();
385
386 uint first = G1_NO_HRM_INDEX;
387 uint obj_regions = (uint) humongous_obj_size_in_regions(word_size);
388
389 if (obj_regions == 1) {
390 // Only one region to allocate, try to use a fast path by directly allocating
391 // from the free lists. Do not try to expand here, we will potentially do that
392 // later.
393 HeapRegion* hr = new_region(word_size, true /* is_old */, false /* do_expand */);
394 if (hr != NULL) {
395 first = hr->hrm_index();
1588 assert_at_safepoint(true /* should_be_vm_thread */);
1589
1590 _verifier->verify_region_sets_optional();
1591
1592 size_t expand_bytes = MAX2(word_size * HeapWordSize, MinHeapDeltaBytes);
1593 log_debug(gc, ergo, heap)("Attempt heap expansion (allocation request failed). Allocation request: " SIZE_FORMAT "B",
1594 word_size * HeapWordSize);
1595
1596
1597 if (expand(expand_bytes, _workers)) {
1598 _hrm.verify_optional();
1599 _verifier->verify_region_sets_optional();
1600 return attempt_allocation_at_safepoint(word_size,
1601 context,
1602 false /* expect_null_mutator_alloc_region */);
1603 }
1604 return NULL;
1605 }
1606
1607 bool G1CollectedHeap::expand(size_t expand_bytes, WorkGang* pretouch_workers, double* expand_time_ms) {
1608 size_t aligned_expand_bytes = ReservedSpace::page_align_size_up(expand_bytes);
1609 aligned_expand_bytes = align_size_up(aligned_expand_bytes,
1610 HeapRegion::GrainBytes);
1611
1612 log_debug(gc, ergo, heap)("Expand the heap. requested expansion amount: " SIZE_FORMAT "B expansion amount: " SIZE_FORMAT "B",
1613 expand_bytes, aligned_expand_bytes);
1614
1615 if (is_maximal_no_gc()) {
1616 log_debug(gc, ergo, heap)("Did not expand the heap (heap already fully expanded)");
1617 return false;
1618 }
1619
1620 double expand_heap_start_time_sec = os::elapsedTime();
1621 uint regions_to_expand = (uint)(aligned_expand_bytes / HeapRegion::GrainBytes);
1622 assert(regions_to_expand > 0, "Must expand by at least one region");
1623
1624 uint expanded_by = _hrm.expand_by(regions_to_expand, pretouch_workers);
1625 if (expand_time_ms != NULL) {
1626 *expand_time_ms = (os::elapsedTime() - expand_heap_start_time_sec) * MILLIUNITS;
1627 }
1628
1629 if (expanded_by > 0) {
1630 size_t actual_expand_bytes = expanded_by * HeapRegion::GrainBytes;
1631 assert(actual_expand_bytes <= aligned_expand_bytes, "post-condition");
1632 g1_policy()->record_new_heap_size(num_regions());
1633 } else {
1634 log_debug(gc, ergo, heap)("Did not expand the heap (heap expansion operation failed)");
1635
1636 // The expansion of the virtual storage space was unsuccessful.
1637 // Let's see if it was because we ran out of swap.
1638 if (G1ExitOnExpansionFailure &&
1639 _hrm.available() >= regions_to_expand) {
1640 // We had head room...
1641 vm_exit_out_of_memory(aligned_expand_bytes, OOM_MMAP_ERROR, "G1 heap expansion");
1642 }
1643 }
1644 return regions_to_expand > 0;
1645 }
1646
1647 void G1CollectedHeap::shrink_helper(size_t shrink_bytes) {
1648 size_t aligned_shrink_bytes =
1649 ReservedSpace::page_align_size_down(shrink_bytes);
1650 aligned_shrink_bytes = align_size_down(aligned_shrink_bytes,
1651 HeapRegion::GrainBytes);
1652 uint num_regions_to_remove = (uint)(shrink_bytes / HeapRegion::GrainBytes);
1653
1654 uint num_regions_removed = _hrm.shrink_by(num_regions_to_remove);
1655 size_t shrunk_bytes = num_regions_removed * HeapRegion::GrainBytes;
1656
1657
1658 log_debug(gc, ergo, heap)("Shrink the heap. requested shrinking amount: " SIZE_FORMAT "B aligned shrinking amount: " SIZE_FORMAT "B attempted shrinking amount: " SIZE_FORMAT "B",
1659 shrink_bytes, aligned_shrink_bytes, shrunk_bytes);
1660 if (num_regions_removed > 0) {
1661 g1_policy()->record_new_heap_size(num_regions());
1662 } else {
1663 log_debug(gc, ergo, heap)("Did not expand the heap (heap shrinking operation failed)");
1664 }
1665 }
1666
1667 void G1CollectedHeap::shrink(size_t shrink_bytes) {
1668 _verifier->verify_region_sets_optional();
1669
1670 // We should only reach here at the end of a Full GC which means we
2418 bool G1CollectedHeap::block_is_obj(const HeapWord* addr) const {
2419 HeapRegion* hr = heap_region_containing(addr);
2420 return hr->block_is_obj(addr);
2421 }
2422
2423 bool G1CollectedHeap::supports_tlab_allocation() const {
2424 return true;
2425 }
2426
2427 size_t G1CollectedHeap::tlab_capacity(Thread* ignored) const {
2428 return (_g1_policy->young_list_target_length() - _survivor.length()) * HeapRegion::GrainBytes;
2429 }
2430
2431 size_t G1CollectedHeap::tlab_used(Thread* ignored) const {
2432 return _eden.length() * HeapRegion::GrainBytes;
2433 }
2434
2435 // For G1 TLABs should not contain humongous objects, so the maximum TLAB size
2436 // must be equal to the humongous object limit.
2437 size_t G1CollectedHeap::max_tlab_size() const {
2438 return align_size_down(_humongous_object_threshold_in_words, MinObjAlignment);
2439 }
2440
2441 size_t G1CollectedHeap::unsafe_max_tlab_alloc(Thread* ignored) const {
2442 AllocationContext_t context = AllocationContext::current();
2443 return _allocator->unsafe_max_tlab_alloc(context);
2444 }
2445
2446 size_t G1CollectedHeap::max_capacity() const {
2447 return _hrm.reserved().byte_size();
2448 }
2449
2450 jlong G1CollectedHeap::millis_since_last_gc() {
2451 // See the notes in GenCollectedHeap::millis_since_last_gc()
2452 // for more information about the implementation.
2453 jlong ret_val = (os::javaTimeNanos() / NANOSECS_PER_MILLISEC) -
2454 _g1_policy->collection_pause_end_millis();
2455 if (ret_val < 0) {
2456 log_warning(gc)("millis_since_last_gc() would return : " JLONG_FORMAT
2457 ". returning zero instead.", ret_val);
2458 return 0;
|
355
356 _verifier->check_bitmaps("Humongous Region Allocation", first_hr);
357
358 assert(words_not_fillable == 0 ||
359 first_hr->bottom() + word_size_sum - words_not_fillable == hr->top(),
360 "Miscalculation in humongous allocation");
361
362 increase_used((word_size_sum - words_not_fillable) * HeapWordSize);
363
364 for (uint i = first; i <= last; ++i) {
365 hr = region_at(i);
366 _humongous_set.add(hr);
367 _hr_printer.alloc(hr);
368 }
369
370 return new_obj;
371 }
372
373 size_t G1CollectedHeap::humongous_obj_size_in_regions(size_t word_size) {
374 assert(is_humongous(word_size), "Object of size " SIZE_FORMAT " must be humongous here", word_size);
375 return align_up_(word_size, HeapRegion::GrainWords) / HeapRegion::GrainWords;
376 }
377
378 // If could fit into free regions w/o expansion, try.
379 // Otherwise, if can expand, do so.
380 // Otherwise, if using ex regions might help, try with ex given back.
381 HeapWord* G1CollectedHeap::humongous_obj_allocate(size_t word_size, AllocationContext_t context) {
382 assert_heap_locked_or_at_safepoint(true /* should_be_vm_thread */);
383
384 _verifier->verify_region_sets_optional();
385
386 uint first = G1_NO_HRM_INDEX;
387 uint obj_regions = (uint) humongous_obj_size_in_regions(word_size);
388
389 if (obj_regions == 1) {
390 // Only one region to allocate, try to use a fast path by directly allocating
391 // from the free lists. Do not try to expand here, we will potentially do that
392 // later.
393 HeapRegion* hr = new_region(word_size, true /* is_old */, false /* do_expand */);
394 if (hr != NULL) {
395 first = hr->hrm_index();
1588 assert_at_safepoint(true /* should_be_vm_thread */);
1589
1590 _verifier->verify_region_sets_optional();
1591
1592 size_t expand_bytes = MAX2(word_size * HeapWordSize, MinHeapDeltaBytes);
1593 log_debug(gc, ergo, heap)("Attempt heap expansion (allocation request failed). Allocation request: " SIZE_FORMAT "B",
1594 word_size * HeapWordSize);
1595
1596
1597 if (expand(expand_bytes, _workers)) {
1598 _hrm.verify_optional();
1599 _verifier->verify_region_sets_optional();
1600 return attempt_allocation_at_safepoint(word_size,
1601 context,
1602 false /* expect_null_mutator_alloc_region */);
1603 }
1604 return NULL;
1605 }
1606
1607 bool G1CollectedHeap::expand(size_t expand_bytes, WorkGang* pretouch_workers, double* expand_time_ms) {
1608 size_t aligned_expand_bytes = ReservedSpace::page_align_up(expand_bytes);
1609 aligned_expand_bytes = align_up(aligned_expand_bytes,
1610 HeapRegion::GrainBytes);
1611
1612 log_debug(gc, ergo, heap)("Expand the heap. requested expansion amount: " SIZE_FORMAT "B expansion amount: " SIZE_FORMAT "B",
1613 expand_bytes, aligned_expand_bytes);
1614
1615 if (is_maximal_no_gc()) {
1616 log_debug(gc, ergo, heap)("Did not expand the heap (heap already fully expanded)");
1617 return false;
1618 }
1619
1620 double expand_heap_start_time_sec = os::elapsedTime();
1621 uint regions_to_expand = (uint)(aligned_expand_bytes / HeapRegion::GrainBytes);
1622 assert(regions_to_expand > 0, "Must expand by at least one region");
1623
1624 uint expanded_by = _hrm.expand_by(regions_to_expand, pretouch_workers);
1625 if (expand_time_ms != NULL) {
1626 *expand_time_ms = (os::elapsedTime() - expand_heap_start_time_sec) * MILLIUNITS;
1627 }
1628
1629 if (expanded_by > 0) {
1630 size_t actual_expand_bytes = expanded_by * HeapRegion::GrainBytes;
1631 assert(actual_expand_bytes <= aligned_expand_bytes, "post-condition");
1632 g1_policy()->record_new_heap_size(num_regions());
1633 } else {
1634 log_debug(gc, ergo, heap)("Did not expand the heap (heap expansion operation failed)");
1635
1636 // The expansion of the virtual storage space was unsuccessful.
1637 // Let's see if it was because we ran out of swap.
1638 if (G1ExitOnExpansionFailure &&
1639 _hrm.available() >= regions_to_expand) {
1640 // We had head room...
1641 vm_exit_out_of_memory(aligned_expand_bytes, OOM_MMAP_ERROR, "G1 heap expansion");
1642 }
1643 }
1644 return regions_to_expand > 0;
1645 }
1646
1647 void G1CollectedHeap::shrink_helper(size_t shrink_bytes) {
1648 size_t aligned_shrink_bytes =
1649 ReservedSpace::page_align_down(shrink_bytes);
1650 aligned_shrink_bytes = align_down(aligned_shrink_bytes,
1651 HeapRegion::GrainBytes);
1652 uint num_regions_to_remove = (uint)(shrink_bytes / HeapRegion::GrainBytes);
1653
1654 uint num_regions_removed = _hrm.shrink_by(num_regions_to_remove);
1655 size_t shrunk_bytes = num_regions_removed * HeapRegion::GrainBytes;
1656
1657
1658 log_debug(gc, ergo, heap)("Shrink the heap. requested shrinking amount: " SIZE_FORMAT "B aligned shrinking amount: " SIZE_FORMAT "B attempted shrinking amount: " SIZE_FORMAT "B",
1659 shrink_bytes, aligned_shrink_bytes, shrunk_bytes);
1660 if (num_regions_removed > 0) {
1661 g1_policy()->record_new_heap_size(num_regions());
1662 } else {
1663 log_debug(gc, ergo, heap)("Did not expand the heap (heap shrinking operation failed)");
1664 }
1665 }
1666
1667 void G1CollectedHeap::shrink(size_t shrink_bytes) {
1668 _verifier->verify_region_sets_optional();
1669
1670 // We should only reach here at the end of a Full GC which means we
2418 bool G1CollectedHeap::block_is_obj(const HeapWord* addr) const {
2419 HeapRegion* hr = heap_region_containing(addr);
2420 return hr->block_is_obj(addr);
2421 }
2422
2423 bool G1CollectedHeap::supports_tlab_allocation() const {
2424 return true;
2425 }
2426
2427 size_t G1CollectedHeap::tlab_capacity(Thread* ignored) const {
2428 return (_g1_policy->young_list_target_length() - _survivor.length()) * HeapRegion::GrainBytes;
2429 }
2430
2431 size_t G1CollectedHeap::tlab_used(Thread* ignored) const {
2432 return _eden.length() * HeapRegion::GrainBytes;
2433 }
2434
2435 // For G1 TLABs should not contain humongous objects, so the maximum TLAB size
2436 // must be equal to the humongous object limit.
2437 size_t G1CollectedHeap::max_tlab_size() const {
2438 return align_down(_humongous_object_threshold_in_words, MinObjAlignment);
2439 }
2440
2441 size_t G1CollectedHeap::unsafe_max_tlab_alloc(Thread* ignored) const {
2442 AllocationContext_t context = AllocationContext::current();
2443 return _allocator->unsafe_max_tlab_alloc(context);
2444 }
2445
2446 size_t G1CollectedHeap::max_capacity() const {
2447 return _hrm.reserved().byte_size();
2448 }
2449
2450 jlong G1CollectedHeap::millis_since_last_gc() {
2451 // See the notes in GenCollectedHeap::millis_since_last_gc()
2452 // for more information about the implementation.
2453 jlong ret_val = (os::javaTimeNanos() / NANOSECS_PER_MILLISEC) -
2454 _g1_policy->collection_pause_end_millis();
2455 if (ret_val < 0) {
2456 log_warning(gc)("millis_since_last_gc() would return : " JLONG_FORMAT
2457 ". returning zero instead.", ret_val);
2458 return 0;
|