--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/gc/cms/commandLineFlagConstraintsCMS.cpp Tue Apr 10 12:17:16 2018 +0200
@@ -0,0 +1,241 @@
+/*
+ * Copyright (c) 2015, 2018, 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.
+ *
+ * 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/cms/commandLineFlagConstraintsCMS.hpp"
+#include "gc/cms/concurrentMarkSweepGeneration.inline.hpp"
+#include "gc/shared/cardTableRS.hpp"
+#include "gc/shared/collectedHeap.hpp"
+#include "gc/shared/genCollectedHeap.hpp"
+#include "gc/shared/commandLineFlagConstraintsGC.hpp"
+#include "memory/universe.hpp"
+#include "runtime/commandLineFlagRangeList.hpp"
+#include "runtime/globals_extension.hpp"
+#include "utilities/globalDefinitions.hpp"
+
+static Flag::Error ParallelGCThreadsAndCMSWorkQueueDrainThreshold(uint threads, uintx threshold, bool verbose) {
+ // CMSWorkQueueDrainThreshold is verified to be less than max_juint
+ if (UseConcMarkSweepGC && (threads > (uint)(max_jint / (uint)threshold))) {
+ CommandLineError::print(verbose,
+ "ParallelGCThreads (" UINT32_FORMAT ") or CMSWorkQueueDrainThreshold ("
+ UINTX_FORMAT ") is too large\n",
+ threads, threshold);
+ return Flag::VIOLATES_CONSTRAINT;
+ }
+ return Flag::SUCCESS;
+}
+
+Flag::Error ParallelGCThreadsConstraintFuncCMS(uint value, bool verbose) {
+ // To avoid overflow at ParScanClosure::do_oop_work.
+ if (UseConcMarkSweepGC && (value > (max_jint / 10))) {
+ CommandLineError::print(verbose,
+ "ParallelGCThreads (" UINT32_FORMAT ") must be "
+ "less than or equal to " UINT32_FORMAT " for CMS GC\n",
+ value, (max_jint / 10));
+ return Flag::VIOLATES_CONSTRAINT;
+ }
+ return ParallelGCThreadsAndCMSWorkQueueDrainThreshold(value, CMSWorkQueueDrainThreshold, verbose);
+}
+Flag::Error ParGCStridesPerThreadConstraintFunc(uintx value, bool verbose) {
+ if (UseConcMarkSweepGC && (value > ((uintx)max_jint / (uintx)ParallelGCThreads))) {
+ CommandLineError::print(verbose,
+ "ParGCStridesPerThread (" UINTX_FORMAT ") must be "
+ "less than or equal to ergonomic maximum (" UINTX_FORMAT ")\n",
+ value, ((uintx)max_jint / (uintx)ParallelGCThreads));
+ return Flag::VIOLATES_CONSTRAINT;
+ }
+ return Flag::SUCCESS;
+}
+
+Flag::Error ParGCCardsPerStrideChunkConstraintFunc(intx value, bool verbose) {
+ if (UseConcMarkSweepGC) {
+ // ParGCCardsPerStrideChunk should be compared with card table size.
+ size_t heap_size = Universe::heap()->reserved_region().word_size();
+ CardTableRS* ct = GenCollectedHeap::heap()->rem_set();
+ size_t card_table_size = ct->cards_required(heap_size) - 1; // Valid card table size
+
+ if ((size_t)value > card_table_size) {
+ CommandLineError::print(verbose,
+ "ParGCCardsPerStrideChunk (" INTX_FORMAT ") is too large for the heap size and "
+ "must be less than or equal to card table size (" SIZE_FORMAT ")\n",
+ value, card_table_size);
+ return Flag::VIOLATES_CONSTRAINT;
+ }
+
+ // ParGCCardsPerStrideChunk is used with n_strides(ParallelGCThreads*ParGCStridesPerThread)
+ // from CardTableRS::process_stride(). Note that ParGCStridesPerThread is already checked
+ // not to make an overflow with ParallelGCThreads from its constraint function.
+ uintx n_strides = ParallelGCThreads * ParGCStridesPerThread;
+ uintx ergo_max = max_uintx / n_strides;
+ if ((uintx)value > ergo_max) {
+ CommandLineError::print(verbose,
+ "ParGCCardsPerStrideChunk (" INTX_FORMAT ") must be "
+ "less than or equal to ergonomic maximum (" UINTX_FORMAT ")\n",
+ value, ergo_max);
+ return Flag::VIOLATES_CONSTRAINT;
+ }
+ }
+ return Flag::SUCCESS;
+}
+
+Flag::Error CMSOldPLABMinConstraintFunc(size_t value, bool verbose) {
+ Flag::Error status = Flag::SUCCESS;
+
+ if (UseConcMarkSweepGC) {
+ if (value > CMSOldPLABMax) {
+ CommandLineError::print(verbose,
+ "CMSOldPLABMin (" SIZE_FORMAT ") must be "
+ "less than or equal to CMSOldPLABMax (" SIZE_FORMAT ")\n",
+ value, CMSOldPLABMax);
+ return Flag::VIOLATES_CONSTRAINT;
+ }
+ status = MaxPLABSizeBounds("CMSOldPLABMin", value, verbose);
+ }
+ return status;
+}
+
+Flag::Error CMSOldPLABMaxConstraintFunc(size_t value, bool verbose) {
+ Flag::Error status = Flag::SUCCESS;
+
+ if (UseConcMarkSweepGC) {
+ status = MaxPLABSizeBounds("CMSOldPLABMax", value, verbose);
+ }
+ return status;
+}
+
+static Flag::Error CMSReservedAreaConstraintFunc(const char* name, size_t value, bool verbose) {
+ if (UseConcMarkSweepGC) {
+ ConcurrentMarkSweepGeneration* cms = (ConcurrentMarkSweepGeneration*)GenCollectedHeap::heap()->old_gen();
+ const size_t ergo_max = cms->cmsSpace()->max_flag_size_for_task_size();
+ if (value > ergo_max) {
+ CommandLineError::print(verbose,
+ "%s (" SIZE_FORMAT ") must be "
+ "less than or equal to ergonomic maximum (" SIZE_FORMAT ") "
+ "which is based on the maximum size of the old generation of the Java heap\n",
+ name, value, ergo_max);
+ return Flag::VIOLATES_CONSTRAINT;
+ }
+ }
+
+ return Flag::SUCCESS;
+}
+
+Flag::Error CMSRescanMultipleConstraintFunc(size_t value, bool verbose) {
+ Flag::Error status = CMSReservedAreaConstraintFunc("CMSRescanMultiple", value, verbose);
+
+ if (status == Flag::SUCCESS && UseConcMarkSweepGC) {
+ // CMSParRemarkTask::do_dirty_card_rescan_tasks requires CompactibleFreeListSpace::rescan_task_size()
+ // to be aligned to CardTable::card_size * BitsPerWord.
+ // Note that rescan_task_size() will be aligned if CMSRescanMultiple is a multiple of 'HeapWordSize'
+ // because rescan_task_size() is CardTable::card_size / HeapWordSize * BitsPerWord.
+ if (value % HeapWordSize != 0) {
+ CommandLineError::print(verbose,
+ "CMSRescanMultiple (" SIZE_FORMAT ") must be "
+ "a multiple of " SIZE_FORMAT "\n",
+ value, HeapWordSize);
+ status = Flag::VIOLATES_CONSTRAINT;
+ }
+ }
+
+ return status;
+}
+
+Flag::Error CMSConcMarkMultipleConstraintFunc(size_t value, bool verbose) {
+ return CMSReservedAreaConstraintFunc("CMSConcMarkMultiple", value, verbose);
+}
+
+Flag::Error CMSPrecleanDenominatorConstraintFunc(uintx value, bool verbose) {
+ if (UseConcMarkSweepGC && (value <= CMSPrecleanNumerator)) {
+ CommandLineError::print(verbose,
+ "CMSPrecleanDenominator (" UINTX_FORMAT ") must be "
+ "strickly greater than CMSPrecleanNumerator (" UINTX_FORMAT ")\n",
+ value, CMSPrecleanNumerator);
+ return Flag::VIOLATES_CONSTRAINT;
+ }
+ return Flag::SUCCESS;
+}
+
+Flag::Error CMSPrecleanNumeratorConstraintFunc(uintx value, bool verbose) {
+ if (UseConcMarkSweepGC && (value >= CMSPrecleanDenominator)) {
+ CommandLineError::print(verbose,
+ "CMSPrecleanNumerator (" UINTX_FORMAT ") must be "
+ "less than CMSPrecleanDenominator (" UINTX_FORMAT ")\n",
+ value, CMSPrecleanDenominator);
+ return Flag::VIOLATES_CONSTRAINT;
+ }
+ return Flag::SUCCESS;
+}
+
+Flag::Error CMSSamplingGrainConstraintFunc(uintx value, bool verbose) {
+ if (UseConcMarkSweepGC) {
+ size_t max_capacity = GenCollectedHeap::heap()->young_gen()->max_capacity();
+ if (value > max_uintx - max_capacity) {
+ CommandLineError::print(verbose,
+ "CMSSamplingGrain (" UINTX_FORMAT ") must be "
+ "less than or equal to ergonomic maximum (" SIZE_FORMAT ")\n",
+ value, max_uintx - max_capacity);
+ return Flag::VIOLATES_CONSTRAINT;
+ }
+ }
+ return Flag::SUCCESS;
+}
+
+Flag::Error CMSWorkQueueDrainThresholdConstraintFunc(uintx value, bool verbose) {
+ if (UseConcMarkSweepGC) {
+ return ParallelGCThreadsAndCMSWorkQueueDrainThreshold(ParallelGCThreads, value, verbose);
+ }
+ return Flag::SUCCESS;
+}
+
+Flag::Error CMSBitMapYieldQuantumConstraintFunc(size_t value, bool verbose) {
+ // Skip for current default value.
+ if (UseConcMarkSweepGC && FLAG_IS_CMDLINE(CMSBitMapYieldQuantum)) {
+ // CMSBitMapYieldQuantum should be compared with mark bitmap size.
+ ConcurrentMarkSweepGeneration* cms = (ConcurrentMarkSweepGeneration*)GenCollectedHeap::heap()->old_gen();
+ size_t bitmap_size = cms->collector()->markBitMap()->sizeInWords();
+
+ if (value > bitmap_size) {
+ CommandLineError::print(verbose,
+ "CMSBitMapYieldQuantum (" SIZE_FORMAT ") must "
+ "be less than or equal to bitmap size (" SIZE_FORMAT ") "
+ "whose size corresponds to the size of old generation of the Java heap\n",
+ value, bitmap_size);
+ return Flag::VIOLATES_CONSTRAINT;
+ }
+ }
+ return Flag::SUCCESS;
+}
+
+Flag::Error OldPLABSizeConstraintFuncCMS(size_t value, bool verbose) {
+ if (value == 0) {
+ CommandLineError::print(verbose,
+ "OldPLABSize (" SIZE_FORMAT ") must be greater than 0",
+ value);
+ return Flag::VIOLATES_CONSTRAINT;
+ }
+ // For CMS, OldPLABSize is the number of free blocks of a given size that are used when
+ // replenishing the local per-worker free list caches.
+ // For more details, please refer to Arguments::set_cms_and_parnew_gc_flags().
+ return MaxPLABSizeBounds("OldPLABSize", value, verbose);
+}