1.1 --- a/src/share/vm/gc_implementation/g1/g1RemSet.cpp Fri Apr 29 12:40:49 2011 -0400
1.2 +++ b/src/share/vm/gc_implementation/g1/g1RemSet.cpp Fri Apr 29 14:59:04 2011 -0400
1.3 @@ -157,7 +157,6 @@
1.4 void set_try_claimed() { _try_claimed = true; }
1.5
1.6 void scanCard(size_t index, HeapRegion *r) {
1.7 - _cards_done++;
1.8 DirtyCardToOopClosure* cl =
1.9 r->new_dcto_closure(_oc,
1.10 CardTableModRefBS::Precise,
1.11 @@ -168,17 +167,14 @@
1.12 HeapWord* card_start = _bot_shared->address_for_index(index);
1.13 HeapWord* card_end = card_start + G1BlockOffsetSharedArray::N_words;
1.14 Space *sp = SharedHeap::heap()->space_containing(card_start);
1.15 - MemRegion sm_region;
1.16 - if (ParallelGCThreads > 0) {
1.17 - // first find the used area
1.18 - sm_region = sp->used_region_at_save_marks();
1.19 - } else {
1.20 - // The closure is not idempotent. We shouldn't look at objects
1.21 - // allocated during the GC.
1.22 - sm_region = sp->used_region_at_save_marks();
1.23 - }
1.24 + MemRegion sm_region = sp->used_region_at_save_marks();
1.25 MemRegion mr = sm_region.intersection(MemRegion(card_start,card_end));
1.26 - if (!mr.is_empty()) {
1.27 + if (!mr.is_empty() && !_ct_bs->is_card_claimed(index)) {
1.28 + // We make the card as "claimed" lazily (so races are possible
1.29 + // but they're benign), which reduces the number of duplicate
1.30 + // scans (the rsets of the regions in the cset can intersect).
1.31 + _ct_bs->set_card_claimed(index);
1.32 + _cards_done++;
1.33 cl->do_MemRegion(mr);
1.34 }
1.35 }
1.36 @@ -199,6 +195,9 @@
1.37 HeapRegionRemSet* hrrs = r->rem_set();
1.38 if (hrrs->iter_is_complete()) return false; // All done.
1.39 if (!_try_claimed && !hrrs->claim_iter()) return false;
1.40 + // If we ever free the collection set concurrently, we should also
1.41 + // clear the card table concurrently therefore we won't need to
1.42 + // add regions of the collection set to the dirty cards region.
1.43 _g1h->push_dirty_cards_region(r);
1.44 // If we didn't return above, then
1.45 // _try_claimed || r->claim_iter()
1.46 @@ -230,15 +229,10 @@
1.47 _g1h->push_dirty_cards_region(card_region);
1.48 }
1.49
1.50 - // If the card is dirty, then we will scan it during updateRS.
1.51 - if (!card_region->in_collection_set() && !_ct_bs->is_card_dirty(card_index)) {
1.52 - // We make the card as "claimed" lazily (so races are possible but they're benign),
1.53 - // which reduces the number of duplicate scans (the rsets of the regions in the cset
1.54 - // can intersect).
1.55 - if (!_ct_bs->is_card_claimed(card_index)) {
1.56 - _ct_bs->set_card_claimed(card_index);
1.57 - scanCard(card_index, card_region);
1.58 - }
1.59 + // If the card is dirty, then we will scan it during updateRS.
1.60 + if (!card_region->in_collection_set() &&
1.61 + !_ct_bs->is_card_dirty(card_index)) {
1.62 + scanCard(card_index, card_region);
1.63 }
1.64 }
1.65 if (!_try_claimed) {
1.66 @@ -246,8 +240,6 @@
1.67 }
1.68 return false;
1.69 }
1.70 - // Set all cards back to clean.
1.71 - void cleanup() {_g1h->cleanUpCardTable();}
1.72 size_t cards_done() { return _cards_done;}
1.73 size_t cards_looked_up() { return _cards;}
1.74 };
1.75 @@ -566,8 +558,9 @@
1.76 update_rs_cl.set_region(r);
1.77 HeapWord* stop_point =
1.78 r->oops_on_card_seq_iterate_careful(scanRegion,
1.79 - &filter_then_update_rs_cset_oop_cl,
1.80 - false /* filter_young */);
1.81 + &filter_then_update_rs_cset_oop_cl,
1.82 + false /* filter_young */,
1.83 + NULL /* card_ptr */);
1.84
1.85 // Since this is performed in the event of an evacuation failure, we
1.86 // we shouldn't see a non-null stop point
1.87 @@ -735,12 +728,6 @@
1.88 (OopClosure*)&mux :
1.89 (OopClosure*)&update_rs_oop_cl));
1.90
1.91 - // Undirty the card.
1.92 - *card_ptr = CardTableModRefBS::clean_card_val();
1.93 - // We must complete this write before we do any of the reads below.
1.94 - OrderAccess::storeload();
1.95 - // And process it, being careful of unallocated portions of TLAB's.
1.96 -
1.97 // The region for the current card may be a young region. The
1.98 // current card may have been a card that was evicted from the
1.99 // card cache. When the card was inserted into the cache, we had
1.100 @@ -749,7 +736,7 @@
1.101 // and tagged as young.
1.102 //
1.103 // We wish to filter out cards for such a region but the current
1.104 - // thread, if we're running conucrrently, may "see" the young type
1.105 + // thread, if we're running concurrently, may "see" the young type
1.106 // change at any time (so an earlier "is_young" check may pass or
1.107 // fail arbitrarily). We tell the iteration code to perform this
1.108 // filtering when it has been determined that there has been an actual
1.109 @@ -759,7 +746,8 @@
1.110 HeapWord* stop_point =
1.111 r->oops_on_card_seq_iterate_careful(dirtyRegion,
1.112 &filter_then_update_rs_oop_cl,
1.113 - filter_young);
1.114 + filter_young,
1.115 + card_ptr);
1.116
1.117 // If stop_point is non-null, then we encountered an unallocated region
1.118 // (perhaps the unfilled portion of a TLAB.) For now, we'll dirty the
