jdk8-mips64-public/hotspot: comparison src/share/vm/gc_implementation/g1/collectionSetChooser.cpp

-:d903bf750e9f
+:a9647476d1a4
 /*
-* Copyright (c) 2001, 2011, Oracle and/or its affiliates. All rights reserved.
+* Copyright (c) 2001, 2012, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.
 }
 }
 #ifndef PRODUCT
 bool CSetChooserCache::verify() {
+guarantee(false, "CSetChooserCache::verify(): don't call this any more");
 int index = _first;
 HeapRegion *prev = NULL;
 for (int i = 0; i < _occupancy; ++i) {
 guarantee(_cache[index] != NULL, "cache entry should not be empty");
 HeapRegion *hr = _cache[index];
 return true;
 }
 #endif // PRODUCT
 void CSetChooserCache::insert(HeapRegion *hr) {
+guarantee(false, "CSetChooserCache::insert(): don't call this any more");
 assert(!is_full(), "cache should not be empty");
 hr->calc_gc_efficiency();
 int empty_index;
 if (_occupancy == 0) {
 ++_occupancy;
 assert(verify(), "cache should be consistent");
 }
 HeapRegion *CSetChooserCache::remove_first() {
+guarantee(false, "CSetChooserCache::remove_first(): "
+"don't call this any more");
 if (_occupancy > 0) {
 assert(_cache[_first] != NULL, "cache should have at least one region");
 HeapRegion *ret = _cache[_first];
 _cache[_first] = NULL;
 ret->set_sort_index(-1);
 } else {
 return NULL;
 }
 }
-static inline int orderRegions(HeapRegion* hr1, HeapRegion* hr2) {
+// Even though we don't use the GC efficiency in our heuristics as
+// much as we used to, we still order according to GC efficiency. This
+// will cause regions with a lot of live objects and large RSets to
+// end up at the end of the array. Given that we might skip collecting
+// the last few old regions, if after a few mixed GCs the remaining
+// have reclaimable bytes under a certain threshold, the hope is that
+// the ones we'll skip are ones with both large RSets and a lot of
+// live objects, not the ones with just a lot of live objects if we
+// ordered according to the amount of reclaimable bytes per region.
+static int orderRegions(HeapRegion* hr1, HeapRegion* hr2) {
 if (hr1 == NULL) {
-if (hr2 == NULL) return 0;
+if (hr2 == NULL) {
-else return 1;
+return 0;
+} else {
+return 1;
+}
 } else if (hr2 == NULL) {
 return -1;
 }
-if (hr2->gc_efficiency() < hr1->gc_efficiency()) return -1;
-else if (hr1->gc_efficiency() < hr2->gc_efficiency()) return 1;
+double gc_eff1 = hr1->gc_efficiency();
-else return 0;
+double gc_eff2 = hr2->gc_efficiency();
+if (gc_eff1 > gc_eff2) {
+return -1;
+} if (gc_eff1 < gc_eff2) {
+return 1;
+} else {
+return 0;
+}
 }
 static int orderRegions(HeapRegion** hr1p, HeapRegion** hr2p) {
 return orderRegions(*hr1p, *hr2p);
 }
 //
 // Note: containing object is allocated on C heap since it is CHeapObj.
 //
 _markedRegions((ResourceObj::set_allocation_type((address)&_markedRegions,
 ResourceObj::C_HEAP),
-100),
+100), true /* C_Heap */),
-true),
+_curr_index(0), _length(0),
-_curMarkedIndex(0),
+_regionLiveThresholdBytes(0), _remainingReclaimableBytes(0),
-_numMarkedRegions(0),
+_first_par_unreserved_idx(0) {
-_unmarked_age_1_returned_as_new(false),
+_regionLiveThresholdBytes =
-_first_par_unreserved_idx(0)
+HeapRegion::GrainBytes * (size_t) G1OldCSetRegionLiveThresholdPercent / 100;
-{}
+}
 #ifndef PRODUCT
 bool CollectionSetChooser::verify() {
+guarantee(_length >= 0, err_msg("_length: %d", _length));
+guarantee(0 <= _curr_index && _curr_index <= _length,
+err_msg("_curr_index: %d _length: %d", _curr_index, _length));
 int index = 0;
-guarantee(_curMarkedIndex <= _numMarkedRegions,
+size_t sum_of_reclaimable_bytes = 0;
-"_curMarkedIndex should be within bounds");
+while (index < _curr_index) {
-while (index < _curMarkedIndex) {
+guarantee(_markedRegions.at(index) == NULL,
-guarantee(_markedRegions.at(index++) == NULL,
+"all entries before _curr_index should be NULL");
-"all entries before _curMarkedIndex should be NULL");
+index += 1;
 }
 HeapRegion *prev = NULL;
-while (index < _numMarkedRegions) {
+while (index < _length) {
 HeapRegion *curr = _markedRegions.at(index++);
 guarantee(curr != NULL, "Regions in _markedRegions array cannot be NULL");
 int si = curr->sort_index();
 guarantee(!curr->is_young(), "should not be young!");
+guarantee(!curr->isHumongous(), "should not be humongous!");
 guarantee(si > -1 && si == (index-1), "sort index invariant");
 if (prev != NULL) {
-guarantee(orderRegions(prev, curr) != 1, "regions should be sorted");
+guarantee(orderRegions(prev, curr) != 1,
-}
+err_msg("GC eff prev: %1.4f GC eff curr: %1.4f",
+prev->gc_efficiency(), curr->gc_efficiency()));
+}
+sum_of_reclaimable_bytes += curr->reclaimable_bytes();
 prev = curr;
 }
-return _cache.verify();
+guarantee(sum_of_reclaimable_bytes == _remainingReclaimableBytes,
+err_msg("reclaimable bytes inconsistent, "
+"remaining: "SIZE_FORMAT" sum: "SIZE_FORMAT,
+_remainingReclaimableBytes, sum_of_reclaimable_bytes));
+return true;
 }
 #endif
-void
+void CollectionSetChooser::fillCache() {
-CollectionSetChooser::fillCache() {
+guarantee(false, "fillCache: don't call this any more");
-while (!_cache.is_full() && (_curMarkedIndex < _numMarkedRegions)) {
-HeapRegion* hr = _markedRegions.at(_curMarkedIndex);
+while (!_cache.is_full() && (_curr_index < _length)) {
+HeapRegion* hr = _markedRegions.at(_curr_index);
 assert(hr != NULL,
 err_msg("Unexpected NULL hr in _markedRegions at index %d",
-_curMarkedIndex));
+_curr_index));
-_curMarkedIndex += 1;
+_curr_index += 1;
 assert(!hr->is_young(), "should not be young!");
-assert(hr->sort_index() == _curMarkedIndex-1, "sort_index invariant");
+assert(hr->sort_index() == _curr_index-1, "sort_index invariant");
 _markedRegions.at_put(hr->sort_index(), NULL);
 _cache.insert(hr);
 assert(!_cache.is_empty(), "cache should not be empty");
 }
 assert(verify(), "cache should be consistent");
 }
-void
+void CollectionSetChooser::sortMarkedHeapRegions() {
-CollectionSetChooser::sortMarkedHeapRegions() {
-guarantee(_cache.is_empty(), "cache should be empty");
 // First trim any unused portion of the top in the parallel case.
 if (_first_par_unreserved_idx > 0) {
 if (G1PrintParCleanupStats) {
 gclog_or_tty->print("     Truncating _markedRegions from %d to %d.\n",
 _markedRegions.length(), _first_par_unreserved_idx);
 assert(_first_par_unreserved_idx <= _markedRegions.length(),
 "Or we didn't reserved enough length");
 _markedRegions.trunc_to(_first_par_unreserved_idx);
 }
 _markedRegions.sort(orderRegions);
-assert(_numMarkedRegions <= _markedRegions.length(), "Requirement");
+assert(_length <= _markedRegions.length(), "Requirement");
-assert(_numMarkedRegions == 0
+assert(_length == 0 || _markedRegions.at(_length - 1) != NULL,
-|| _markedRegions.at(_numMarkedRegions-1) != NULL,
+"Testing _length");
-"Testing _numMarkedRegions");
+assert(_length == _markedRegions.length() ||
-assert(_numMarkedRegions == _markedRegions.length()
+_markedRegions.at(_length) == NULL, "Testing _length");
-|| _markedRegions.at(_numMarkedRegions) == NULL,
-"Testing _numMarkedRegions");
 if (G1PrintParCleanupStats) {
-gclog_or_tty->print_cr("     Sorted %d marked regions.", _numMarkedRegions);
+gclog_or_tty->print_cr("     Sorted %d marked regions.", _length);
 }
-for (int i = 0; i < _numMarkedRegions; i++) {
+for (int i = 0; i < _length; i++) {
 assert(_markedRegions.at(i) != NULL, "Should be true by sorting!");
 _markedRegions.at(i)->set_sort_index(i);
 }
 if (G1PrintRegionLivenessInfo) {
 G1PrintRegionLivenessInfoClosure cl(gclog_or_tty, "Post-Sorting");
-for (int i = 0; i < _numMarkedRegions; ++i) {
+for (int i = 0; i < _length; ++i) {
 HeapRegion* r = _markedRegions.at(i);
 cl.doHeapRegion(r);
 }
 }
-assert(verify(), "should now be sorted");
+assert(verify(), "CSet chooser verification");
 }
-void
+size_t CollectionSetChooser::calcMinOldCSetLength() {
-CollectionSetChooser::addMarkedHeapRegion(HeapRegion* hr) {
+// The min old CSet region bound is based on the maximum desired
+// number of mixed GCs after a cycle. I.e., even if some old regions
+// look expensive, we should add them to the CSet anyway to make
+// sure we go through the available old regions in no more than the
+// maximum desired number of mixed GCs.
+//
+// The calculation is based on the number of marked regions we added
+// to the CSet chooser in the first place, not how many remain, so
+// that the result is the same during all mixed GCs that follow a cycle.
+const size_t region_num = (size_t) _length;
+const size_t gc_num = (size_t) G1MaxMixedGCNum;
+size_t result = region_num / gc_num;
+// emulate ceiling
+if (result * gc_num < region_num) {
+result += 1;
+}
+return result;
+}
+size_t CollectionSetChooser::calcMaxOldCSetLength() {
+// The max old CSet region bound is based on the threshold expressed
+// as a percentage of the heap size. I.e., it should bound the
+// number of old regions added to the CSet irrespective of how many
+// of them are available.
+G1CollectedHeap* g1h = G1CollectedHeap::heap();
+const size_t region_num = g1h->n_regions();
+const size_t perc = (size_t) G1OldCSetRegionThresholdPercent;
+size_t result = region_num * perc / 100;
+// emulate ceiling
+if (100 * result < region_num * perc) {
+result += 1;
+}
+return result;
+}
+void CollectionSetChooser::addMarkedHeapRegion(HeapRegion* hr) {
 assert(!hr->isHumongous(),
 "Humongous regions shouldn't be added to the collection set");
 assert(!hr->is_young(), "should not be young!");
 _markedRegions.append(hr);
-_numMarkedRegions++;
+_length++;
+_remainingReclaimableBytes += hr->reclaimable_bytes();
 hr->calc_gc_efficiency();
 }
-void
+void CollectionSetChooser::prepareForAddMarkedHeapRegionsPar(size_t n_regions,
-CollectionSetChooser::
+size_t chunkSize) {
-prepareForAddMarkedHeapRegionsPar(size_t n_regions, size_t chunkSize) {
 _first_par_unreserved_idx = 0;
 int n_threads = ParallelGCThreads;
 if (UseDynamicNumberOfGCThreads) {
 assert(G1CollectedHeap::heap()->workers()->active_workers() > 0,
 "Should have been set earlier");
 (n_regions + (chunkSize - 1)) / chunkSize * chunkSize;
 assert( aligned_n_regions % chunkSize == 0, "should be aligned" );
 _markedRegions.at_put_grow((int)(aligned_n_regions + max_waste - 1), NULL);
 }
-jint
+jint CollectionSetChooser::getParMarkedHeapRegionChunk(jint n_regions) {
-CollectionSetChooser::getParMarkedHeapRegionChunk(jint n_regions) {
 // Don't do this assert because this can be called at a point
 // where the loop up stream will not execute again but might
 // try to claim more chunks (loop test has not been done yet).
 // assert(_markedRegions.length() > _first_par_unreserved_idx,
 //  "Striding beyond the marked regions");
 assert(_markedRegions.length() > res + n_regions - 1,
 "Should already have been expanded");
 return res - n_regions;
 }
-void
+void CollectionSetChooser::setMarkedHeapRegion(jint index, HeapRegion* hr) {
-CollectionSetChooser::setMarkedHeapRegion(jint index, HeapRegion* hr) {
 assert(_markedRegions.at(index) == NULL, "precondition");
 assert(!hr->is_young(), "should not be young!");
 _markedRegions.at_put(index, hr);
 hr->calc_gc_efficiency();
 }
-void
+void CollectionSetChooser::updateTotals(jint region_num,
-CollectionSetChooser::incNumMarkedHeapRegions(jint inc_by) {
+size_t reclaimable_bytes) {
-(void)Atomic::add(inc_by, &_numMarkedRegions);
+// Only take the lock if we actually need to update the totals.
-}
+if (region_num > 0) {
+assert(reclaimable_bytes > 0, "invariant");
-void
+// We could have just used atomics instead of taking the
-CollectionSetChooser::clearMarkedHeapRegions(){
+// lock. However, we currently don't have an atomic add for size_t.
+MutexLockerEx x(ParGCRareEvent_lock, Mutex::_no_safepoint_check_flag);
+_length += (int) region_num;
+_remainingReclaimableBytes += reclaimable_bytes;
+} else {
+assert(reclaimable_bytes == 0, "invariant");
+}
+}
+void CollectionSetChooser::clearMarkedHeapRegions() {
 for (int i = 0; i < _markedRegions.length(); i++) {
-HeapRegion* r =   _markedRegions.at(i);
+HeapRegion* r = _markedRegions.at(i);
-if (r != NULL) r->set_sort_index(-1);
+if (r != NULL) {
+r->set_sort_index(-1);
+}
 }
 _markedRegions.clear();
-_curMarkedIndex = 0;
+_curr_index = 0;
-_numMarkedRegions = 0;
+_length = 0;
-_cache.clear();
+_remainingReclaimableBytes = 0;
 };
-void
-CollectionSetChooser::updateAfterFullCollection() {
-clearMarkedHeapRegions();
-}
-// if time_remaining < 0.0, then this method should try to return
-// a region, whether it fits within the remaining time or not
-HeapRegion*
-CollectionSetChooser::getNextMarkedRegion(double time_remaining,
-double avg_prediction) {
-G1CollectedHeap* g1h = G1CollectedHeap::heap();
-G1CollectorPolicy* g1p = g1h->g1_policy();
-fillCache();
-if (_cache.is_empty()) {
-assert(_curMarkedIndex == _numMarkedRegions,
-"if cache is empty, list should also be empty");
-ergo_verbose0(ErgoCSetConstruction,
-"stop adding old regions to CSet",
-ergo_format_reason("cache is empty"));
-return NULL;
-}
-HeapRegion *hr = _cache.get_first();
-assert(hr != NULL, "if cache not empty, first entry should be non-null");
-double predicted_time = g1h->predict_region_elapsed_time_ms(hr, false);
-if (g1p->adaptive_young_list_length()) {
-if (time_remaining - predicted_time < 0.0) {
-g1h->check_if_region_is_too_expensive(predicted_time);
-ergo_verbose2(ErgoCSetConstruction,
-"stop adding old regions to CSet",
-ergo_format_reason("predicted old region time higher than remaining time")
-ergo_format_ms("predicted old region time")
-ergo_format_ms("remaining time"),
-predicted_time, time_remaining);
-return NULL;
-}
-} else {
-double threshold = 2.0 * avg_prediction;
-if (predicted_time > threshold) {
-ergo_verbose2(ErgoCSetConstruction,
-"stop adding old regions to CSet",
-ergo_format_reason("predicted old region time higher than threshold")
-ergo_format_ms("predicted old region time")
-ergo_format_ms("threshold"),
-predicted_time, threshold);
-return NULL;
-}
-}
-HeapRegion *hr2 = _cache.remove_first();
-assert(hr == hr2, "cache contents should not have changed");
-return hr;
-}

Mercurial > jdk8-mips64-public > hotspot / file comparison

comparison: src/share/vm/gc_implementation/g1/collectionSetChooser.cpp

src/share/vm/gc_implementation/g1/collectionSetChooser.cpp