/* * Copyright (c) 2001, 2020, 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. * */ #ifndef SHARE_GC_G1_G1_GLOBALS_HPP #define SHARE_GC_G1_G1_GLOBALS_HPP #include "runtime/globals_shared.hpp" // // Declare all globals flags used by the garbage-first compiler. // #include "utilities/macros.hpp" #if INCLUDE_G1GC #include "runtime/flags/jvmFlag.hpp" PRODUCT_FLAG(bool, G1UseAdaptiveIHOP, true, JVMFlag::DEFAULT, "Adaptively adjust the initiating heap occupancy from the " "initial value of InitiatingHeapOccupancyPercent. The policy " "attempts to start marking in time based on application " "behavior."); PRODUCT_FLAG(size_t, G1AdaptiveIHOPNumInitialSamples, 3, JVMFlag::EXPERIMENTAL | JVMFlag::RANGE, "How many completed time periods from initial mark to first " "mixed gc are required to use the input values for prediction " "of the optimal occupancy to start marking."); FLAG_RANGE( G1AdaptiveIHOPNumInitialSamples, 1, max_intx); PRODUCT_FLAG(uintx, G1ConfidencePercent, 50, JVMFlag::RANGE, "Confidence level for MMU/pause predictions"); FLAG_RANGE( G1ConfidencePercent, 0, 100); PRODUCT_FLAG(intx, G1SummarizeRSetStatsPeriod, 0, JVMFlag::DIAGNOSTIC | JVMFlag::RANGE, "The period (in number of GCs) at which we will generate " "update buffer processing info " "(0 means do not periodically generate this info); " "it also requires that logging is enabled on the trace" "level for gc+remset"); FLAG_RANGE( G1SummarizeRSetStatsPeriod, 0, max_intx); PRODUCT_FLAG(double, G1ConcMarkStepDurationMillis, 10.0, JVMFlag::RANGE, "Target duration of individual concurrent marking steps " "in milliseconds."); FLAG_RANGE( G1ConcMarkStepDurationMillis, 1.0, DBL_MAX); PRODUCT_FLAG(uint, G1RefProcDrainInterval, 1000, JVMFlag::RANGE, "The number of discovered reference objects to process before " "draining concurrent marking work queues."); FLAG_RANGE( G1RefProcDrainInterval, 1, INT_MAX); PRODUCT_FLAG(bool, G1UseReferencePrecleaning, true, JVMFlag::EXPERIMENTAL, "Concurrently preclean java.lang.ref.references instances " "before the Remark pause."); PRODUCT_FLAG(double, G1LastPLABAverageOccupancy, 50.0, JVMFlag::EXPERIMENTAL | JVMFlag::RANGE, "The expected average occupancy of the last PLAB in " "percent."); FLAG_RANGE( G1LastPLABAverageOccupancy, 0.001, 100.0); PRODUCT_FLAG(size_t, G1SATBBufferSize, 1*K, JVMFlag::RANGE, "Number of entries in an SATB log buffer."); FLAG_RANGE( G1SATBBufferSize, 1, max_uintx); DEVELOP_FLAG(intx, G1SATBProcessCompletedThreshold, 20, JVMFlag::RANGE, "Number of completed buffers that triggers log processing."); FLAG_RANGE( G1SATBProcessCompletedThreshold, 0, max_jint); PRODUCT_FLAG(uintx, G1SATBBufferEnqueueingThresholdPercent, 60, JVMFlag::RANGE, "Before enqueueing them, each mutator thread tries to do some " "filtering on the SATB buffers it generates. If post-filtering " "the percentage of retained entries is over this threshold " "the buffer will be enqueued for processing. A value of 0 " "specifies that mutator threads should not do such filtering."); FLAG_RANGE( G1SATBBufferEnqueueingThresholdPercent, 0, 100); PRODUCT_FLAG(intx, G1ExpandByPercentOfAvailable, 20, JVMFlag::EXPERIMENTAL | JVMFlag::RANGE, "When expanding, % of uncommitted space to claim."); FLAG_RANGE( G1ExpandByPercentOfAvailable, 0, 100); PRODUCT_FLAG(size_t, G1UpdateBufferSize, 256, JVMFlag::RANGE, "Size of an update buffer"); FLAG_RANGE( G1UpdateBufferSize, 1, NOT_LP64(32*M) LP64_ONLY(1*G)); PRODUCT_FLAG(size_t, G1ConcRefinementYellowZone, 0, JVMFlag::RANGE, "Number of enqueued update buffers that will " "trigger concurrent processing. Will be selected ergonomically " "by default."); FLAG_RANGE( G1ConcRefinementYellowZone, 0, max_intx); PRODUCT_FLAG(size_t, G1ConcRefinementRedZone, 0, JVMFlag::RANGE, "Maximum number of enqueued update buffers before mutator " "threads start processing new ones instead of enqueueing them. " "Will be selected ergonomically by default."); FLAG_RANGE( G1ConcRefinementRedZone, 0, max_intx); PRODUCT_FLAG(size_t, G1ConcRefinementGreenZone, 0, JVMFlag::RANGE, "The number of update buffers that are left in the queue by the " "concurrent processing threads. Will be selected ergonomically " "by default."); FLAG_RANGE( G1ConcRefinementGreenZone, 0, max_intx); PRODUCT_FLAG(uintx, G1ConcRefinementServiceIntervalMillis, 300, JVMFlag::RANGE, "The last concurrent refinement thread wakes up every " "specified number of milliseconds to do miscellaneous work."); FLAG_RANGE( G1ConcRefinementServiceIntervalMillis, 0, max_jint); PRODUCT_FLAG(size_t, G1ConcRefinementThresholdStep, 2, JVMFlag::RANGE, "Each time the rset update queue increases by this amount " "activate the next refinement thread if available. " "The actual step size will be selected ergonomically by " "default, with this value used to determine a lower bound."); FLAG_RANGE( G1ConcRefinementThresholdStep, 1, SIZE_MAX); PRODUCT_FLAG(intx, G1RSetUpdatingPauseTimePercent, 10, JVMFlag::RANGE, "A target percentage of time that is allowed to be spend on " "process RS update buffers during the collection pause."); FLAG_RANGE( G1RSetUpdatingPauseTimePercent, 0, 100); PRODUCT_FLAG(bool, G1UseAdaptiveConcRefinement, true, JVMFlag::DEFAULT, "Select green, yellow and red zones adaptively to meet the " "the pause requirements."); PRODUCT_FLAG(size_t, G1ConcRSLogCacheSize, 10, JVMFlag::RANGE, "Log base 2 of the length of conc RS hot-card cache."); FLAG_RANGE( G1ConcRSLogCacheSize, 0, 27); PRODUCT_FLAG(uintx, G1ConcRSHotCardLimit, 4, JVMFlag::RANGE, "The threshold that defines (>=) a hot card."); FLAG_RANGE( G1ConcRSHotCardLimit, 0, max_jubyte); DEVELOP_FLAG(intx, G1RSetRegionEntriesBase, 256, JVMFlag::RANGE, "Max number of regions in a fine-grain table per MB."); FLAG_RANGE( G1RSetRegionEntriesBase, 1, max_jint/wordSize); PRODUCT_FLAG(intx, G1RSetRegionEntries, 0, JVMFlag::RANGE | JVMFlag::CONSTRAINT, "Max number of regions for which we keep bitmaps." "Will be set ergonomically by default"); FLAG_RANGE( G1RSetRegionEntries, 0, max_jint/wordSize); FLAG_CONSTRAINT( G1RSetRegionEntries, (void*)G1RSetRegionEntriesConstraintFunc, JVMFlag::AfterErgo); DEVELOP_FLAG(intx, G1RSetSparseRegionEntriesBase, 4, JVMFlag::RANGE, "Max number of entries per region in a sparse table " "per MB."); FLAG_RANGE( G1RSetSparseRegionEntriesBase, 1, max_jint/wordSize); PRODUCT_FLAG(intx, G1RSetSparseRegionEntries, 0, JVMFlag::RANGE | JVMFlag::CONSTRAINT, "Max number of entries per region in a sparse table." "Will be set ergonomically by default."); FLAG_RANGE( G1RSetSparseRegionEntries, 0, max_jint/wordSize); FLAG_CONSTRAINT( G1RSetSparseRegionEntries, (void*)G1RSetSparseRegionEntriesConstraintFunc, JVMFlag::AfterErgo); DEVELOP_FLAG(intx, G1MaxVerifyFailures, -1, JVMFlag::RANGE, "The maximum number of verification failures to print. " "-1 means print all."); FLAG_RANGE( G1MaxVerifyFailures, -1, max_jint); PRODUCT_FLAG(uintx, G1ReservePercent, 10, JVMFlag::RANGE, "It determines the minimum reserve we should have in the heap " "to minimize the probability of promotion failure."); FLAG_RANGE( G1ReservePercent, 0, 50); PRODUCT_FLAG(size_t, G1HeapRegionSize, 0, JVMFlag::RANGE | JVMFlag::CONSTRAINT, "Size of the G1 regions."); FLAG_RANGE( G1HeapRegionSize, 0, 32*M); FLAG_CONSTRAINT( G1HeapRegionSize, (void*)G1HeapRegionSizeConstraintFunc, JVMFlag::AfterMemoryInit); PRODUCT_FLAG(uint, G1ConcRefinementThreads, 0, JVMFlag::RANGE, "The number of parallel rem set update threads. " "Will be set ergonomically by default."); FLAG_RANGE( G1ConcRefinementThreads, 0, (max_jint-1)/wordSize); DEVELOP_FLAG(bool, G1VerifyCTCleanup, false, JVMFlag::DEFAULT, "Verify card table cleanup."); DEVELOP_FLAG(uintx, G1DummyRegionsPerGC, 0, JVMFlag::DEFAULT, "The number of dummy regions G1 will allocate at the end of " "each evacuation pause in order to artificially fill up the " "heap and stress the marking implementation."); DEVELOP_FLAG(bool, G1ExitOnExpansionFailure, false, JVMFlag::DEFAULT, "Raise a fatal VM exit out of memory failure in the event " " that heap expansion fails due to running out of swap."); PRODUCT_FLAG(uintx, G1MaxNewSizePercent, 60, JVMFlag::EXPERIMENTAL | JVMFlag::RANGE | JVMFlag::CONSTRAINT, "Percentage (0-100) of the heap size to use as default " " maximum young gen size."); FLAG_RANGE( G1MaxNewSizePercent, 0, 100); FLAG_CONSTRAINT( G1MaxNewSizePercent, (void*)G1MaxNewSizePercentConstraintFunc, JVMFlag::AfterErgo); PRODUCT_FLAG(uintx, G1NewSizePercent, 5, JVMFlag::EXPERIMENTAL | JVMFlag::RANGE | JVMFlag::CONSTRAINT, "Percentage (0-100) of the heap size to use as default " "minimum young gen size."); FLAG_RANGE( G1NewSizePercent, 0, 100); FLAG_CONSTRAINT( G1NewSizePercent, (void*)G1NewSizePercentConstraintFunc, JVMFlag::AfterErgo); PRODUCT_FLAG(uintx, G1MixedGCLiveThresholdPercent, 85, JVMFlag::EXPERIMENTAL | JVMFlag::RANGE, "Threshold for regions to be considered for inclusion in the " "collection set of mixed GCs. " "Regions with live bytes exceeding this will not be collected."); FLAG_RANGE( G1MixedGCLiveThresholdPercent, 0, 100); PRODUCT_FLAG(uintx, G1HeapWastePercent, 5, JVMFlag::RANGE, "Amount of space, expressed as a percentage of the heap size, " "that G1 is willing not to collect to avoid expensive GCs."); FLAG_RANGE( G1HeapWastePercent, 0, 100); PRODUCT_FLAG(uintx, G1MixedGCCountTarget, 8, JVMFlag::RANGE, "The target number of mixed GCs after a marking cycle."); FLAG_RANGE( G1MixedGCCountTarget, 0, max_uintx); PRODUCT_FLAG(bool, G1EagerReclaimHumongousObjects, true, JVMFlag::EXPERIMENTAL, "Try to reclaim dead large objects at every young GC."); PRODUCT_FLAG(bool, G1EagerReclaimHumongousObjectsWithStaleRefs, true, JVMFlag::EXPERIMENTAL, "Try to reclaim dead large objects that have a few stale " "references at every young GC."); PRODUCT_FLAG(size_t, G1RebuildRemSetChunkSize, 256 * K, JVMFlag::EXPERIMENTAL | JVMFlag::RANGE, "Chunk size used for rebuilding the remembered set."); FLAG_RANGE( G1RebuildRemSetChunkSize, 4 * K, 32 * M); PRODUCT_FLAG(uintx, G1OldCSetRegionThresholdPercent, 10, JVMFlag::EXPERIMENTAL | JVMFlag::RANGE, "An upper bound for the number of old CSet regions expressed " "as a percentage of the heap size."); FLAG_RANGE( G1OldCSetRegionThresholdPercent, 0, 100); NOTPROD_FLAG(bool, G1EvacuationFailureALot, false, JVMFlag::DEFAULT, "Force use of evacuation failure handling during certain " "evacuation pauses"); DEVELOP_FLAG(uintx, G1EvacuationFailureALotCount, 1000, JVMFlag::DEFAULT, "Number of successful evacuations between evacuation failures " "occurring at object copying"); DEVELOP_FLAG(uintx, G1EvacuationFailureALotInterval, 5, JVMFlag::DEFAULT, "Total collections between forced triggering of evacuation " "failures"); DEVELOP_FLAG(bool, G1EvacuationFailureALotDuringConcMark, true, JVMFlag::DEFAULT, "Force use of evacuation failure handling during evacuation " "pauses when marking is in progress"); DEVELOP_FLAG(bool, G1EvacuationFailureALotDuringInitialMark, true, JVMFlag::DEFAULT, "Force use of evacuation failure handling during initial mark " "evacuation pauses"); DEVELOP_FLAG(bool, G1EvacuationFailureALotDuringYoungGC, true, JVMFlag::DEFAULT, "Force use of evacuation failure handling during young " "evacuation pauses"); DEVELOP_FLAG(bool, G1EvacuationFailureALotDuringMixedGC, true, JVMFlag::DEFAULT, "Force use of evacuation failure handling during mixed " "evacuation pauses"); PRODUCT_FLAG(bool, G1VerifyRSetsDuringFullGC, false, JVMFlag::DIAGNOSTIC, "If true, perform verification of each heap region's " "remembered set when verifying the heap during a full GC."); PRODUCT_FLAG(bool, G1VerifyHeapRegionCodeRoots, false, JVMFlag::DIAGNOSTIC, "Verify the code root lists attached to each heap region."); DEVELOP_FLAG(bool, G1VerifyBitmaps, false, JVMFlag::DEFAULT, "Verifies the consistency of the marking bitmaps"); PRODUCT_FLAG(uintx, G1PeriodicGCInterval, 0, JVMFlag::MANAGEABLE, "Number of milliseconds after a previous GC to wait before " "triggering a periodic gc. A value of zero disables periodically " "enforced gc cycles."); PRODUCT_FLAG(bool, G1PeriodicGCInvokesConcurrent, true, JVMFlag::DEFAULT, "Determines the kind of periodic GC. Set to true to have G1 " "perform a concurrent GC as periodic GC, otherwise use a STW " "Full GC."); PRODUCT_FLAG(double, G1PeriodicGCSystemLoadThreshold, 0.0, JVMFlag::MANAGEABLE | JVMFlag::RANGE, "Maximum recent system wide load as returned by the 1m value " "of getloadavg() at which G1 triggers a periodic GC. A load " "above this value cancels a given periodic GC. A value of zero " "disables this check."); FLAG_RANGE( G1PeriodicGCSystemLoadThreshold, 0.0, (double)max_uintx); PRODUCT_FLAG(uintx, G1YoungExpansionBufferPercent, 10, JVMFlag::EXPERIMENTAL | JVMFlag::RANGE, "When heterogenous heap is enabled by AllocateOldGenAt " "option, after every GC, young gen is re-sized which " "involves system calls to commit/uncommit memory. To " "reduce these calls, we keep a buffer of extra regions to " "absorb small changes in young gen length. This flag takes " "the buffer size as an percentage of young gen length"); FLAG_RANGE( G1YoungExpansionBufferPercent, 0, 100); #endif // INCLUDE_G1GC #endif // SHARE_GC_G1_G1_GLOBALS_HPP