Mercurial > hg > graal-compiler
diff src/share/vm/gc_implementation/g1/heapRegionSeq.cpp @ 20337:1f1d373cd044
8038423: G1: Decommit memory within heap
Summary: Allow G1 to decommit memory of arbitrary regions within the heap and their associated auxiliary data structures card table, BOT, hot card cache, and mark bitmaps.
Reviewed-by: mgerdin, brutisso, jwilhelm
author | tschatzl |
---|---|
date | Thu, 21 Aug 2014 11:47:10 +0200 |
parents | 6701abbc4441 |
children |
line wrap: on
line diff
--- a/src/share/vm/gc_implementation/g1/heapRegionSeq.cpp Tue Aug 19 10:50:27 2014 +0200 +++ b/src/share/vm/gc_implementation/g1/heapRegionSeq.cpp Thu Aug 21 11:47:10 2014 +0200 @@ -30,19 +30,33 @@ #include "gc_implementation/g1/concurrentG1Refine.hpp" #include "memory/allocation.hpp" -void HeapRegionSeq::initialize(ReservedSpace reserved) { - _reserved = reserved; - _storage.initialize(reserved, 0); - - _num_committed = 0; - +void HeapRegionSeq::initialize(G1RegionToSpaceMapper* heap_storage, + G1RegionToSpaceMapper* prev_bitmap, + G1RegionToSpaceMapper* next_bitmap, + G1RegionToSpaceMapper* bot, + G1RegionToSpaceMapper* cardtable, + G1RegionToSpaceMapper* card_counts) { _allocated_heapregions_length = 0; - _regions.initialize((HeapWord*)_storage.low_boundary(), (HeapWord*)_storage.high_boundary(), HeapRegion::GrainBytes); + _heap_mapper = heap_storage; + + _prev_bitmap_mapper = prev_bitmap; + _next_bitmap_mapper = next_bitmap; + + _bot_mapper = bot; + _cardtable_mapper = cardtable; + + _card_counts_mapper = card_counts; + + MemRegion reserved = heap_storage->reserved(); + _regions.initialize(reserved.start(), reserved.end(), HeapRegion::GrainBytes); + + _available_map.resize(_regions.length(), false); + _available_map.clear(); } bool HeapRegionSeq::is_available(uint region) const { - return region < _num_committed; + return _available_map.at(region); } #ifdef ASSERT @@ -58,29 +72,26 @@ return new HeapRegion(hrs_index, G1CollectedHeap::heap()->bot_shared(), mr); } -void HeapRegionSeq::update_committed_space(HeapWord* old_end, - HeapWord* new_end) { - assert(old_end != new_end, "don't call this otherwise"); - // We may not have officially committed the area. So construct and use a separate one. - MemRegion new_committed(heap_bottom(), new_end); - // Tell the card table about the update. - Universe::heap()->barrier_set()->resize_covered_region(new_committed); - // Tell the BOT about the update. - G1CollectedHeap::heap()->bot_shared()->resize(new_committed.word_size()); - // Tell the hot card cache about the update - G1CollectedHeap::heap()->concurrent_g1_refine()->hot_card_cache()->resize_card_counts(new_committed.byte_size()); -} - void HeapRegionSeq::commit_regions(uint index, size_t num_regions) { guarantee(num_regions > 0, "Must commit more than zero regions"); guarantee(_num_committed + num_regions <= max_length(), "Cannot commit more than the maximum amount of regions"); - _storage.expand_by(num_regions * HeapRegion::GrainBytes); - update_committed_space(heap_top(), heap_top() + num_regions * HeapRegion::GrainWords); + _num_committed += (uint)num_regions; + + _heap_mapper->commit_regions(index, num_regions); + + // Also commit auxiliary data + _prev_bitmap_mapper->commit_regions(index, num_regions); + _next_bitmap_mapper->commit_regions(index, num_regions); + + _bot_mapper->commit_regions(index, num_regions); + _cardtable_mapper->commit_regions(index, num_regions); + + _card_counts_mapper->commit_regions(index, num_regions); } void HeapRegionSeq::uncommit_regions(uint start, size_t num_regions) { - guarantee(num_regions >= 1, "Need to specify at least one region to uncommit"); + guarantee(num_regions >= 1, err_msg("Need to specify at least one region to uncommit, tried to uncommit zero regions at %u", start)); guarantee(_num_committed >= num_regions, "pre-condition"); // Print before uncommitting. @@ -91,12 +102,19 @@ } } - HeapWord* old_end = heap_top(); _num_committed -= (uint)num_regions; - OrderAccess::fence(); + + _available_map.par_clear_range(start, start + num_regions, BitMap::unknown_range); + _heap_mapper->uncommit_regions(start, num_regions); - _storage.shrink_by(num_regions * HeapRegion::GrainBytes); - update_committed_space(old_end, heap_top()); + // Also uncommit auxiliary data + _prev_bitmap_mapper->uncommit_regions(start, num_regions); + _next_bitmap_mapper->uncommit_regions(start, num_regions); + + _bot_mapper->uncommit_regions(start, num_regions); + _cardtable_mapper->uncommit_regions(start, num_regions); + + _card_counts_mapper->uncommit_regions(start, num_regions); } void HeapRegionSeq::make_regions_available(uint start, uint num_regions) { @@ -110,9 +128,7 @@ } } - _num_committed += (size_t)num_regions; - - OrderAccess::fence(); + _available_map.par_set_range(start, start + num_regions, BitMap::unknown_range); for (uint i = start; i < start + num_regions; i++) { assert(is_available(i), err_msg("Just made region %u available but is apparently not.", i)); @@ -129,8 +145,7 @@ } uint HeapRegionSeq::expand_by(uint num_regions) { - // Only ever expand from the end of the heap. - return expand_at(_num_committed, num_regions); + return expand_at(0, num_regions); } uint HeapRegionSeq::expand_at(uint start, uint num_regions) { @@ -334,7 +349,8 @@ uint idx_last_found = 0; uint num_last_found = 0; - if ((num_last_found = find_empty_from_idx_reverse(cur, &idx_last_found)) > 0) { + while ((removed < num_regions_to_remove) && + (num_last_found = find_empty_from_idx_reverse(cur, &idx_last_found)) > 0) { // Only allow uncommit from the end of the heap. if ((idx_last_found + num_last_found) != _allocated_heapregions_length) { return 0;