8155233: Lazy coarse map clear

Only clear the coarse bitmaps of the remembered sets if they were dirtied.

Reviewed-by: jmasa, mgerdin
This commit is contained in:
Thomas Schatzl 2016-05-02 10:24:41 +02:00
parent 72977f4009
commit 53d670b469
2 changed files with 13 additions and 4 deletions

View File

@ -265,7 +265,8 @@ OtherRegionsTable::OtherRegionsTable(HeapRegion* hr, Mutex* m) :
_first_all_fine_prts(NULL), _last_all_fine_prts(NULL),
_n_fine_entries(0), _n_coarse_entries(0),
_fine_eviction_start(0),
_sparse_table(hr)
_sparse_table(hr),
_coarse_dirty(false)
{
typedef PerRegionTable* PerRegionTablePtr;
@ -504,6 +505,7 @@ PerRegionTable* OtherRegionsTable::delete_region_table() {
size_t max_hrm_index = (size_t) max->hr()->hrm_index();
if (!_coarse_map.at(max_hrm_index)) {
_coarse_map.at_put(max_hrm_index, true);
_coarse_dirty = true;
_n_coarse_entries++;
}
@ -519,8 +521,11 @@ void OtherRegionsTable::scrub(G1CardLiveData* live_data) {
log_develop_trace(gc, remset, scrub)("Scrubbing region %u:", _hr->hrm_index());
log_develop_trace(gc, remset, scrub)(" Coarse map: before = " SIZE_FORMAT "...", _n_coarse_entries);
live_data->remove_nonlive_regions(&_coarse_map);
_n_coarse_entries = _coarse_map.count_one_bits();
if (_coarse_dirty) {
live_data->remove_nonlive_regions(&_coarse_map);
_n_coarse_entries = _coarse_map.count_one_bits();
_coarse_dirty = _n_coarse_entries != 0;
}
log_develop_trace(gc, remset, scrub)(" after = " SIZE_FORMAT ".", _n_coarse_entries);
// Now do the fine-grained maps.
@ -646,7 +651,10 @@ void OtherRegionsTable::clear() {
_first_all_fine_prts = _last_all_fine_prts = NULL;
_sparse_table.clear();
_coarse_map.clear();
if (_coarse_dirty) {
_coarse_map.clear();
_coarse_dirty = false;
}
_n_fine_entries = 0;
_n_coarse_entries = 0;

View File

@ -79,6 +79,7 @@ class OtherRegionsTable VALUE_OBJ_CLASS_SPEC {
HeapRegion* _hr;
// These are protected by "_m".
bool _coarse_dirty;
BitMap _coarse_map;
size_t _n_coarse_entries;
static jint _n_coarsenings;