jdk-sandbox: comparison hotspot/src/share/vm/gc

equal deleted inserted replaced

-:b4cf1910f23e
+:0c3db8869263
 OopsInHeapRegionClosure* _oc;
 G1BlockOffsetSharedArray* _bot_shared;
 CardTableModRefBS *_ct_bs;
 int _worker_i;
 bool _try_claimed;
+size_t _min_skip_distance, _max_skip_distance;
 public:
 ScanRSClosure(OopsInHeapRegionClosure* oc, int worker_i) :
 _oc(oc),
 _cards(0),
 _cards_done(0),
 _try_claimed(false)
 {
 _g1h = G1CollectedHeap::heap();
 _bot_shared = _g1h->bot_shared();
 _ct_bs = (CardTableModRefBS*) (_g1h->barrier_set());
+_min_skip_distance = 16;
+_max_skip_distance = 2 * _g1h->n_par_threads() * _min_skip_distance;
 }
 void set_try_claimed() { _try_claimed = true; }
 void scanCard(size_t index, HeapRegion *r) {
 // is true: either we're supposed to work on claimed-but-not-complete
 // regions, or we successfully claimed the region.
 HeapRegionRemSetIterator* iter = _g1h->rem_set_iterator(_worker_i);
 hrrs->init_iterator(iter);
 size_t card_index;
+size_t skip_distance = 0, current_card = 0, jump_to_card = 0;
 while (iter->has_next(card_index)) {
+if (current_card < jump_to_card) {
+++current_card;
+continue;
+}
 HeapWord* card_start = _g1h->bot_shared()->address_for_index(card_index);
 #if 0
 gclog_or_tty->print("Rem set iteration yielded card [" PTR_FORMAT ", " PTR_FORMAT ").\n",
 card_start, card_start + CardTableModRefBS::card_size_in_words);
 #endif
 HeapRegion* card_region = _g1h->heap_region_containing(card_start);
 assert(card_region != NULL, "Yielding cards not in the heap?");
 _cards++;
-if (!card_region->in_collection_set()) {
+// If the card is dirty, then we will scan it during updateRS.
-// If the card is dirty, then we will scan it during updateRS.
+if (!card_region->in_collection_set() && !_ct_bs->is_card_dirty(card_index)) {
-if (!_ct_bs->is_card_claimed(card_index) &&
+if (!_ct_bs->is_card_claimed(card_index) && _ct_bs->claim_card(card_index)) {
-!_ct_bs->is_card_dirty(card_index)) {
-assert(_ct_bs->is_card_clean(card_index) ||
-_ct_bs->is_card_claimed(card_index) ||
-_ct_bs->is_card_deferred(card_index),
-"Card is either clean, claimed or deferred");
-if (_ct_bs->claim_card(card_index))
 scanCard(card_index, card_region);
-}
+} else if (_try_claimed) {
+if (jump_to_card == 0 || jump_to_card != current_card) {
+// We did some useful work in the previous iteration.
+// Decrease the distance.
+skip_distance = MAX2(skip_distance >> 1, _min_skip_distance);
+} else {
+// Previous iteration resulted in a claim failure.
+// Increase the distance.
+skip_distance = MIN2(skip_distance << 1, _max_skip_distance);
+}
+jump_to_card = current_card + skip_distance;
+}
 }
-}
+++current_card;
-hrrs->set_iter_complete();
+}
+if (!_try_claimed) {
+hrrs->set_iter_complete();
+}
 return false;
 }
 // Set all cards back to clean.
 void cleanup() {_g1h->cleanUpCardTable();}
 size_t cards_done() { return _cards_done;}

changeset 2737	0c3db8869263
parent 2344	f2e09ba7ceab
child 2741	34e2a243d69a