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*
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*
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* version 2 for more details (a copy is included in the LICENSE file that
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#ifndef SHARE_GC_G1_G1_GLOBALS_HPP
#define SHARE_GC_G1_G1_GLOBALS_HPP
#include "runtime/globals_shared.hpp"
//
// Defines all globals flags used by the garbage-first compiler.
//
#define GC_G1_FLAGS(develop, \
develop_pd, \
product, \
product_pd, \
diagnostic, \
diagnostic_pd, \
experimental, \
notproduct, \
manageable, \
product_rw, \
lp64_product, \
range, \
constraint, \
writeable) \
\
product(bool, G1UseAdaptiveIHOP, true, \
"Adaptively adjust the initiating heap occupancy from the " \
"initial value of InitiatingHeapOccupancyPercent. The policy " \
"attempts to start marking in time based on application " \
"behavior.") \
\
experimental(size_t, G1AdaptiveIHOPNumInitialSamples, 3, \
"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.") \
range(1, max_intx) \
\
product(uintx, G1ConfidencePercent, 50, \
"Confidence level for MMU/pause predictions") \
range(0, 100) \
\
diagnostic(intx, G1SummarizeRSetStatsPeriod, 0, \
"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") \
range(0, max_intx) \
\
product(double, G1ConcMarkStepDurationMillis, 10.0, \
"Target duration of individual concurrent marking steps " \
"in milliseconds.") \
range(1.0, DBL_MAX) \
\
product(uint, G1RefProcDrainInterval, 1000, \
"The number of discovered reference objects to process before " \
"draining concurrent marking work queues.") \
range(1, INT_MAX) \
\
experimental(bool, G1UseReferencePrecleaning, true, \
"Concurrently preclean java.lang.ref.references instances " \
"before the Remark pause.") \
\
experimental(double, G1LastPLABAverageOccupancy, 50.0, \
"The expected average occupancy of the last PLAB in " \
"percent.") \
range(0.001, 100.0) \
\
product(size_t, G1SATBBufferSize, 1*K, \
"Number of entries in an SATB log buffer.") \
range(1, max_uintx) \
\
develop(intx, G1SATBProcessCompletedThreshold, 20, \
"Number of completed buffers that triggers log processing.") \
range(0, max_jint) \
\
product(uintx, G1SATBBufferEnqueueingThresholdPercent, 60, \
"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.") \
range(0, 100) \
\
experimental(intx, G1ExpandByPercentOfAvailable, 20, \
"When expanding, % of uncommitted space to claim.") \
range(0, 100) \
\
product(size_t, G1UpdateBufferSize, 256, \
"Size of an update buffer") \
range(1, NOT_LP64(32*M) LP64_ONLY(1*G)) \
\
product(size_t, G1ConcRefinementYellowZone, 0, \
"Number of enqueued update buffers that will " \
"trigger concurrent processing. Will be selected ergonomically " \
"by default.") \
range(0, max_intx) \
\
product(size_t, G1ConcRefinementRedZone, 0, \
"Maximum number of enqueued update buffers before mutator " \
"threads start processing new ones instead of enqueueing them. " \
"Will be selected ergonomically by default.") \
range(0, max_intx) \
\
product(size_t, G1ConcRefinementGreenZone, 0, \
"The number of update buffers that are left in the queue by the " \
"concurrent processing threads. Will be selected ergonomically " \
"by default.") \
range(0, max_intx) \
\
product(uintx, G1ConcRefinementServiceIntervalMillis, 300, \
"The last concurrent refinement thread wakes up every " \
"specified number of milliseconds to do miscellaneous work.") \
range(0, max_jint) \
\
product(size_t, G1ConcRefinementThresholdStep, 2, \
"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.") \
range(1, SIZE_MAX) \
\
product(intx, G1RSetUpdatingPauseTimePercent, 10, \
"A target percentage of time that is allowed to be spend on " \
"process RS update buffers during the collection pause.") \
range(0, 100) \
\
product(bool, G1UseAdaptiveConcRefinement, true, \
"Select green, yellow and red zones adaptively to meet the " \
"the pause requirements.") \
\
product(size_t, G1ConcRSLogCacheSize, 10, \
"Log base 2 of the length of conc RS hot-card cache.") \
range(0, 27) \
\
product(uintx, G1ConcRSHotCardLimit, 4, \
"The threshold that defines (>=) a hot card.") \
range(0, max_jubyte) \
\
develop(intx, G1RSetRegionEntriesBase, 256, \
"Max number of regions in a fine-grain table per MB.") \
range(1, max_jint/wordSize) \
\
product(intx, G1RSetRegionEntries, 0, \
"Max number of regions for which we keep bitmaps." \
"Will be set ergonomically by default") \
range(0, max_jint/wordSize) \
constraint(G1RSetRegionEntriesConstraintFunc,AfterErgo) \
\
develop(intx, G1RSetSparseRegionEntriesBase, 4, \
"Max number of entries per region in a sparse table " \
"per MB.") \
range(1, max_jint/wordSize) \
\
product(intx, G1RSetSparseRegionEntries, 0, \
"Max number of entries per region in a sparse table." \
"Will be set ergonomically by default.") \
range(0, max_jint/wordSize) \
constraint(G1RSetSparseRegionEntriesConstraintFunc,AfterErgo) \
\
develop(intx, G1MaxVerifyFailures, -1, \
"The maximum number of verification failures to print. " \
"-1 means print all.") \
range(-1, max_jint) \
\
product(uintx, G1ReservePercent, 10, \
"It determines the minimum reserve we should have in the heap " \
"to minimize the probability of promotion failure.") \
range(0, 50) \
\
product(size_t, G1HeapRegionSize, 0, \
"Size of the G1 regions.") \
range(0, 32*M) \
constraint(G1HeapRegionSizeConstraintFunc,AfterMemoryInit) \
\
product(uint, G1ConcRefinementThreads, 0, \
"The number of parallel rem set update threads. " \
"Will be set ergonomically by default.") \
range(0, (max_jint-1)/wordSize) \
\
develop(bool, G1VerifyCTCleanup, false, \
"Verify card table cleanup.") \
\
product(size_t, G1RSetScanBlockSize, 64, \
"Size of a work unit of cards claimed by a worker thread" \
"during RSet scanning.") \
range(1, max_uintx) \
\
develop(uintx, G1DummyRegionsPerGC, 0, \
"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(bool, G1ExitOnExpansionFailure, false, \
"Raise a fatal VM exit out of memory failure in the event " \
" that heap expansion fails due to running out of swap.") \
\
experimental(uintx, G1MaxNewSizePercent, 60, \
"Percentage (0-100) of the heap size to use as default " \
" maximum young gen size.") \
range(0, 100) \
constraint(G1MaxNewSizePercentConstraintFunc,AfterErgo) \
\
experimental(uintx, G1NewSizePercent, 5, \
"Percentage (0-100) of the heap size to use as default " \
"minimum young gen size.") \
range(0, 100) \
constraint(G1NewSizePercentConstraintFunc,AfterErgo) \
\
experimental(uintx, G1MixedGCLiveThresholdPercent, 85, \
"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.") \
range(0, 100) \
\
product(uintx, G1HeapWastePercent, 5, \
"Amount of space, expressed as a percentage of the heap size, " \
"that G1 is willing not to collect to avoid expensive GCs.") \
range(0, 100) \
\
product(uintx, G1MixedGCCountTarget, 8, \
"The target number of mixed GCs after a marking cycle.") \
range(0, max_uintx) \
\
experimental(bool, G1EagerReclaimHumongousObjects, true, \
"Try to reclaim dead large objects at every young GC.") \
\
experimental(bool, G1EagerReclaimHumongousObjectsWithStaleRefs, true, \
"Try to reclaim dead large objects that have a few stale " \
"references at every young GC.") \
\
experimental(size_t, G1RebuildRemSetChunkSize, 256 * K, \
"Chunk size used for rebuilding the remembered set.") \
range(4 * K, 32 * M) \
\
experimental(uintx, G1OldCSetRegionThresholdPercent, 10, \
"An upper bound for the number of old CSet regions expressed " \
"as a percentage of the heap size.") \
range(0, 100) \
\
notproduct(bool, G1EvacuationFailureALot, false, \
"Force use of evacuation failure handling during certain " \
"evacuation pauses") \
\
develop(uintx, G1EvacuationFailureALotCount, 1000, \
"Number of successful evacuations between evacuation failures " \
"occurring at object copying") \
\
develop(uintx, G1EvacuationFailureALotInterval, 5, \
"Total collections between forced triggering of evacuation " \
"failures") \
\
develop(bool, G1EvacuationFailureALotDuringConcMark, true, \
"Force use of evacuation failure handling during evacuation " \
"pauses when marking is in progress") \
\
develop(bool, G1EvacuationFailureALotDuringInitialMark, true, \
"Force use of evacuation failure handling during initial mark " \
"evacuation pauses") \
\
develop(bool, G1EvacuationFailureALotDuringYoungGC, true, \
"Force use of evacuation failure handling during young " \
"evacuation pauses") \
\
develop(bool, G1EvacuationFailureALotDuringMixedGC, true, \
"Force use of evacuation failure handling during mixed " \
"evacuation pauses") \
\
diagnostic(bool, G1VerifyRSetsDuringFullGC, false, \
"If true, perform verification of each heap region's " \
"remembered set when verifying the heap during a full GC.") \
\
diagnostic(bool, G1VerifyHeapRegionCodeRoots, false, \
"Verify the code root lists attached to each heap region.") \
\
develop(bool, G1VerifyBitmaps, false, \
"Verifies the consistency of the marking bitmaps") \
\
manageable(uintx, G1PeriodicGCInterval, 0, \
"Number of milliseconds after a previous GC to wait before " \
"triggering a periodic gc. A value of zero disables periodically "\
"enforced gc cycles.") \
\
product(bool, G1PeriodicGCInvokesConcurrent, true, \
"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.") \
\
manageable(double, G1PeriodicGCSystemLoadThreshold, 0.0, \
"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.") \
range(0.0, (double)max_uintx) \
\
experimental(uintx, G1YoungExpansionBufferPercent, 10, \
"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") \
range(0, 100) \
#endif // SHARE_GC_G1_G1_GLOBALS_HPP