--- /dev/null 2018-12-03 11:58:50.256341286 +0100 +++ new/src/hotspot/share/gc/shenandoah/heuristics/shenandoahStaticHeuristics.cpp 2018-12-03 17:47:28.343400898 +0100 @@ -0,0 +1,93 @@ +/* + * Copyright (c) 2018, Red Hat, Inc. All rights reserved. + * + * 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. + * + * This code is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * version 2 for more details (a copy is included in the LICENSE file that + * accompanied this code). + * + * You should have received a copy of the GNU General Public License version + * 2 along with this work; if not, write to the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. + * + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA + * or visit www.oracle.com if you need additional information or have any + * questions. + * + */ + +#include "precompiled.hpp" + +#include "gc/shenandoah/heuristics/shenandoahStaticHeuristics.hpp" +#include "gc/shenandoah/shenandoahCollectionSet.hpp" +#include "gc/shenandoah/shenandoahFreeSet.hpp" +#include "gc/shenandoah/shenandoahHeapRegion.hpp" +#include "logging/log.hpp" +#include "logging/logTag.hpp" + +ShenandoahStaticHeuristics::ShenandoahStaticHeuristics() : ShenandoahHeuristics() { + // Static heuristics may degrade to continuous if live data is larger + // than free threshold. ShenandoahAllocationThreshold is supposed to break this, + // but it only works if it is non-zero. + SHENANDOAH_ERGO_OVERRIDE_DEFAULT(ShenandoahAllocationThreshold, 1); + + SHENANDOAH_ERGO_ENABLE_FLAG(ExplicitGCInvokesConcurrent); + SHENANDOAH_ERGO_ENABLE_FLAG(ShenandoahImplicitGCInvokesConcurrent); + + // Final configuration checks + SHENANDOAH_CHECK_FLAG_SET(ShenandoahSATBBarrier); + SHENANDOAH_CHECK_FLAG_SET(ShenandoahReadBarrier); + SHENANDOAH_CHECK_FLAG_SET(ShenandoahWriteBarrier); + SHENANDOAH_CHECK_FLAG_SET(ShenandoahStoreValReadBarrier); + SHENANDOAH_CHECK_FLAG_SET(ShenandoahKeepAliveBarrier); + SHENANDOAH_CHECK_FLAG_SET(ShenandoahCASBarrier); + SHENANDOAH_CHECK_FLAG_SET(ShenandoahAcmpBarrier); + SHENANDOAH_CHECK_FLAG_SET(ShenandoahCloneBarrier); +} + +ShenandoahStaticHeuristics::~ShenandoahStaticHeuristics() {} + +bool ShenandoahStaticHeuristics::should_start_normal_gc() const { + ShenandoahHeap* heap = ShenandoahHeap::heap(); + + size_t capacity = heap->capacity(); + size_t available = heap->free_set()->available(); + size_t threshold_available = (capacity * ShenandoahFreeThreshold) / 100; + + if (available < threshold_available) { + log_info(gc)("Trigger: Free (" SIZE_FORMAT "M) is below free threshold (" SIZE_FORMAT "M)", + available / M, threshold_available / M); + return true; + } + return ShenandoahHeuristics::should_start_normal_gc(); +} + +void ShenandoahStaticHeuristics::choose_collection_set_from_regiondata(ShenandoahCollectionSet* cset, + RegionData* data, size_t size, + size_t free) { + size_t threshold = ShenandoahHeapRegion::region_size_bytes() * ShenandoahGarbageThreshold / 100; + + for (size_t idx = 0; idx < size; idx++) { + ShenandoahHeapRegion* r = data[idx]._region; + if (r->garbage() > threshold) { + cset->add_region(r); + } + } +} + +const char* ShenandoahStaticHeuristics::name() { + return "static"; +} + +bool ShenandoahStaticHeuristics::is_diagnostic() { + return false; +} + +bool ShenandoahStaticHeuristics::is_experimental() { + return false; +}