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8038423: G1: Decommit memory within heap

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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
This commit is contained in:
Thomas Schatzl 2014-08-19 14:09:10 +02:00
parent 2617d54723
commit 100e51a339
32 changed files with 1322 additions and 579 deletions
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66
hotspot/src/share/vm/memory/cardTableModRefBS.cpp
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@ -44,13 +44,6 @@
// enumerate ref fields that have been modified (since the last
// enumeration.)
size_t CardTableModRefBS::cards_required(size_t covered_words)
{
// Add one for a guard card, used to detect errors.
const size_t words = align_size_up(covered_words, card_size_in_words);
return words / card_size_in_words + 1;
}
size_t CardTableModRefBS::compute_byte_map_size()
{
assert(_guard_index == cards_required(_whole_heap.word_size()) - 1,
@ -64,27 +57,50 @@ CardTableModRefBS::CardTableModRefBS(MemRegion whole_heap,
int max_covered_regions):
ModRefBarrierSet(max_covered_regions),
_whole_heap(whole_heap),
_guard_index(cards_required(whole_heap.word_size()) - 1),
_last_valid_index(_guard_index - 1),
_guard_index(0),
_guard_region(),
_last_valid_index(0),
_page_size(os::vm_page_size()),
_byte_map_size(compute_byte_map_size())
_byte_map_size(0),
_covered(NULL),
_committed(NULL),
_cur_covered_regions(0),
_byte_map(NULL),
byte_map_base(NULL),
// LNC functionality
_lowest_non_clean(NULL),
_lowest_non_clean_chunk_size(NULL),
_lowest_non_clean_base_chunk_index(NULL),
_last_LNC_resizing_collection(NULL)
{
_kind = BarrierSet::CardTableModRef;
HeapWord* low_bound = _whole_heap.start();
HeapWord* high_bound = _whole_heap.end();
assert((uintptr_t(low_bound) & (card_size - 1)) == 0, "heap must start at card boundary");
assert((uintptr_t(high_bound) & (card_size - 1)) == 0, "heap must end at card boundary");
assert((uintptr_t(_whole_heap.start()) & (card_size - 1)) == 0, "heap must start at card boundary");
assert((uintptr_t(_whole_heap.end()) & (card_size - 1)) == 0, "heap must end at card boundary");
assert(card_size <= 512, "card_size must be less than 512"); // why?
_covered = new MemRegion[max_covered_regions];
_committed = new MemRegion[max_covered_regions];
if (_covered == NULL || _committed == NULL) {
vm_exit_during_initialization("couldn't alloc card table covered region set.");
_covered = new MemRegion[_max_covered_regions];
if (_covered == NULL) {
vm_exit_during_initialization("Could not allocate card table covered region set.");
}
}
void CardTableModRefBS::initialize() {
_guard_index = cards_required(_whole_heap.word_size()) - 1;
_last_valid_index = _guard_index - 1;
_byte_map_size = compute_byte_map_size();
HeapWord* low_bound = _whole_heap.start();
HeapWord* high_bound = _whole_heap.end();
_cur_covered_regions = 0;
_committed = new MemRegion[_max_covered_regions];
if (_committed == NULL) {
vm_exit_during_initialization("Could not allocate card table committed region set.");
}
const size_t rs_align = _page_size == (size_t) os::vm_page_size() ? 0 :
MAX2(_page_size, (size_t) os::vm_allocation_granularity());
ReservedSpace heap_rs(_byte_map_size, rs_align, false);
@ -114,20 +130,20 @@ CardTableModRefBS::CardTableModRefBS(MemRegion whole_heap,
!ExecMem, "card table last card");
*guard_card = last_card;
_lowest_non_clean =
NEW_C_HEAP_ARRAY(CardArr, max_covered_regions, mtGC);
_lowest_non_clean =
NEW_C_HEAP_ARRAY(CardArr, _max_covered_regions, mtGC);
_lowest_non_clean_chunk_size =
NEW_C_HEAP_ARRAY(size_t, max_covered_regions, mtGC);
NEW_C_HEAP_ARRAY(size_t, _max_covered_regions, mtGC);
_lowest_non_clean_base_chunk_index =
NEW_C_HEAP_ARRAY(uintptr_t, max_covered_regions, mtGC);
NEW_C_HEAP_ARRAY(uintptr_t, _max_covered_regions, mtGC);
_last_LNC_resizing_collection =
NEW_C_HEAP_ARRAY(int, max_covered_regions, mtGC);
NEW_C_HEAP_ARRAY(int, _max_covered_regions, mtGC);
if (_lowest_non_clean == NULL
|| _lowest_non_clean_chunk_size == NULL
|| _lowest_non_clean_base_chunk_index == NULL
|| _last_LNC_resizing_collection == NULL)
vm_exit_during_initialization("couldn't allocate an LNC array.");
for (int i = 0; i < max_covered_regions; i++) {
for (int i = 0; i < _max_covered_regions; i++) {
_lowest_non_clean[i] = NULL;
_lowest_non_clean_chunk_size[i] = 0;
_last_LNC_resizing_collection[i] = -1;
@ -650,7 +666,7 @@ void CardTableModRefBS::verify_region(MemRegion mr,
jbyte val, bool val_equals) {
jbyte* start = byte_for(mr.start());
jbyte* end = byte_for(mr.last());
bool failures = false;
bool failures = false;
for (jbyte* curr = start; curr <= end; ++curr) {
jbyte curr_val = *curr;
bool failed = (val_equals) ? (curr_val != val) : (curr_val == val);