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8027959: Early reclamation of large objects in G1

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Try to reclaim humongous objects at every young collection after doing a conservative estimate of its liveness.

Reviewed-by: brutisso, mgerdin
This commit is contained in:
Thomas Schatzl 2014-07-23 09:03:32 +02:00
parent bc56e061ec
commit f161bd6d16
12 changed files with 537 additions and 32 deletions
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42
hotspot/src/share/vm/gc_implementation/g1/g1CollectedHeap.inline.hpp
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@ -40,6 +40,13 @@
// Return the region with the given index. It assumes the index is valid.
inline HeapRegion* G1CollectedHeap::region_at(uint index) const { return _hrs.at(index); }
inline uint G1CollectedHeap::addr_to_region(HeapWord* addr) const {
assert(is_in_reserved(addr),
err_msg("Cannot calculate region index for address "PTR_FORMAT" that is outside of the heap ["PTR_FORMAT", "PTR_FORMAT")",
p2i(addr), p2i(_reserved.start()), p2i(_reserved.end())));
return (uint)(pointer_delta(addr, _reserved.start(), sizeof(uint8_t)) >> HeapRegion::LogOfHRGrainBytes);
}
template <class T>
inline HeapRegion*
G1CollectedHeap::heap_region_containing_raw(const T addr) const {
@ -172,12 +179,11 @@ inline bool G1CollectedHeap::isMarkedNext(oop obj) const {
return _cm->nextMarkBitMap()->isMarked((HeapWord *)obj);
}
// This is a fast test on whether a reference points into the
// collection set or not. Assume that the reference
// points into the heap.
inline bool G1CollectedHeap::in_cset_fast_test(oop obj) {
bool ret = _in_cset_fast_test.get_by_address((HeapWord*)obj);
inline bool G1CollectedHeap::is_in_cset(oop obj) {
bool ret = _in_cset_fast_test.is_in_cset((HeapWord*)obj);
// let's make sure the result is consistent with what the slower
// test returns
assert( ret || !obj_in_cs(obj), "sanity");
@ -185,6 +191,18 @@ inline bool G1CollectedHeap::in_cset_fast_test(oop obj) {
return ret;
}
bool G1CollectedHeap::is_in_cset_or_humongous(const oop obj) {
return _in_cset_fast_test.is_in_cset_or_humongous((HeapWord*)obj);
}
G1CollectedHeap::in_cset_state_t G1CollectedHeap::in_cset_state(const oop obj) {
return _in_cset_fast_test.at((HeapWord*)obj);
}
void G1CollectedHeap::register_humongous_region_with_in_cset_fast_test(uint index) {
_in_cset_fast_test.set_humongous(index);
}
#ifndef PRODUCT
// Support for G1EvacuationFailureALot
@ -288,4 +306,22 @@ inline bool G1CollectedHeap::is_obj_ill(const oop obj) const {
return is_obj_ill(obj, heap_region_containing(obj));
}
inline void G1CollectedHeap::set_humongous_is_live(oop obj) {
uint region = addr_to_region((HeapWord*)obj);
// We not only set the "live" flag in the humongous_is_live table, but also
// reset the entry in the _in_cset_fast_test table so that subsequent references
// to the same humongous object do not go into the slow path again.
// This is racy, as multiple threads may at the same time enter here, but this
// is benign.
// During collection we only ever set the "live" flag, and only ever clear the
// entry in the in_cset_fast_table.
// We only ever evaluate the contents of these tables (in the VM thread) after
// having synchronized the worker threads with the VM thread, or in the same
// thread (i.e. within the VM thread).
if (!_humongous_is_live.is_live(region)) {
_humongous_is_live.set_live(region);
_in_cset_fast_test.clear_humongous(region);
}
}
#endif // SHARE_VM_GC_IMPLEMENTATION_G1_G1COLLECTEDHEAP_INLINE_HPP