6994297: G1: do first-level slow-path allocations with a CAS
Summary: First attempt to allocate out the current alloc region using a CAS instead of taking the Heap_lock (first level of G1's slow allocation path). Only if that fails and it's necessary to replace the current alloc region take the Heap_lock (that's the second level of G1's slow allocation path).
Reviewed-by: johnc, brutisso, ysr
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#ifndef SHARE_VM_GC_IMPLEMENTATION_G1_G1_GLOBALS_HPP
#define SHARE_VM_GC_IMPLEMENTATION_G1_G1_GLOBALS_HPP
#include "runtime/globals.hpp"
//
// Defines all globals flags used by the garbage-first compiler.
//
#define G1_FLAGS(develop, develop_pd, product, product_pd, diagnostic, experimental, notproduct, manageable, product_rw) \
\
product(intx, G1ConfidencePercent, 50, \
"Confidence level for MMU/pause predictions") \
\
develop(intx, G1MarkingOverheadPercent, 0, \
"Overhead of concurrent marking") \
\
develop(bool, G1Gen, true, \
"If true, it will enable the generational G1") \
\
develop(intx, G1PolicyVerbose, 0, \
"The verbosity level on G1 policy decisions") \
\
develop(intx, G1MarkingVerboseLevel, 0, \
"Level (0-4) of verboseness of the marking code") \
\
develop(bool, G1PrintReachableAtInitialMark, false, \
"Reachable object dump at the initial mark pause") \
\
develop(bool, G1VerifyDuringGCPrintReachable, false, \
"If conc mark verification fails, dump reachable objects") \
\
develop(ccstr, G1PrintReachableBaseFile, NULL, \
"The base file name for the reachable object dumps") \
\
develop(bool, G1TraceMarkStackOverflow, false, \
"If true, extra debugging code for CM restart for ovflw.") \
\
develop(intx, G1PausesBtwnConcMark, -1, \
"If positive, fixed number of pauses between conc markings") \
\
diagnostic(bool, G1SummarizeConcMark, false, \
"Summarize concurrent mark info") \
\
diagnostic(bool, G1SummarizeRSetStats, false, \
"Summarize remembered set processing info") \
\
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 -XX:+G1SummarizeRSetStats") \
\
diagnostic(bool, G1SummarizeZFStats, false, \
"Summarize zero-filling info") \
\
diagnostic(bool, G1TraceConcRefinement, false, \
"Trace G1 concurrent refinement") \
\
product(intx, G1MarkRegionStackSize, 1024 * 1024, \
"Size of the region stack for concurrent marking.") \
\
develop(bool, G1ConcZeroFill, true, \
"If true, run concurrent zero-filling thread") \
\
develop(intx, G1ConcZFMaxRegions, 1, \
"Stop zero-filling when # of zf'd regions reaches") \
\
develop(bool, G1SATBBarrierPrintNullPreVals, false, \
"If true, count frac of ptr writes with null pre-vals.") \
\
product(intx, G1SATBBufferSize, 1*K, \
"Number of entries in an SATB log buffer.") \
\
develop(intx, G1SATBProcessCompletedThreshold, 20, \
"Number of completed buffers that triggers log processing.") \
\
develop(intx, G1ExtraRegionSurvRate, 33, \
"If the young survival rate is S, and there's room left in " \
"to-space, we will allow regions whose survival rate is up to " \
"S + (1 - S)*X, where X is this parameter (as a fraction.)") \
\
develop(intx, G1InitYoungSurvRatio, 50, \
"Expected Survival Rate for newly allocated bytes") \
\
develop(bool, G1SATBPrintStubs, false, \
"If true, print generated stubs for the SATB barrier") \
\
experimental(intx, G1ExpandByPercentOfAvailable, 20, \
"When expanding, % of uncommitted space to claim.") \
\
develop(bool, G1RSBarrierRegionFilter, true, \
"If true, generate region filtering code in RS barrier") \
\
develop(bool, G1RSBarrierNullFilter, true, \
"If true, generate null-pointer filtering code in RS barrier") \
\
develop(bool, G1PrintCTFilterStats, false, \
"If true, print stats on RS filtering effectiveness") \
\
develop(bool, G1DeferredRSUpdate, true, \
"If true, use deferred RS updates") \
\
develop(bool, G1RSLogCheckCardTable, false, \
"If true, verify that no dirty cards remain after RS log " \
"processing.") \
\
develop(bool, G1RSCountHisto, false, \
"If true, print a histogram of RS occupancies after each pause") \
\
develop(intx, G1PrintRegionLivenessInfo, 0, \
"When > 0, print the occupancies of the <n> best and worst" \
"regions.") \
\
develop(bool, G1PrintParCleanupStats, false, \
"When true, print extra stats about parallel cleanup.") \
\
develop(bool, G1DisablePreBarrier, false, \
"Disable generation of pre-barrier (i.e., marking barrier) ") \
\
develop(bool, G1DisablePostBarrier, false, \
"Disable generation of post-barrier (i.e., RS barrier) ") \
\
product(intx, G1UpdateBufferSize, 256, \
"Size of an update buffer") \
\
product(intx, G1ConcRefinementYellowZone, 0, \
"Number of enqueued update buffers that will " \
"trigger concurrent processing. Will be selected ergonomically " \
"by default.") \
\
product(intx, 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. Zero will disable " \
"concurrent processing.") \
\
product(intx, G1ConcRefinementGreenZone, 0, \
"The number of update buffers that are left in the queue by the " \
"concurrent processing threads. Will be selected ergonomically " \
"by default.") \
\
product(intx, G1ConcRefinementServiceIntervalMillis, 300, \
"The last concurrent refinement thread wakes up every " \
"specified number of milliseconds to do miscellaneous work.") \
\
product(intx, G1ConcRefinementThresholdStep, 0, \
"Each time the rset update queue increases by this amount " \
"activate the next refinement thread if available. " \
"Will be selected ergonomically by default.") \
\
product(intx, G1RSetUpdatingPauseTimePercent, 10, \
"A target percentage of time that is allowed to be spend on " \
"process RS update buffers during the collection pause.") \
\
product(bool, G1UseAdaptiveConcRefinement, true, \
"Select green, yellow and red zones adaptively to meet the " \
"the pause requirements.") \
\
develop(intx, G1ConcRSLogCacheSize, 10, \
"Log base 2 of the length of conc RS hot-card cache.") \
\
develop(intx, G1ConcRSHotCardLimit, 4, \
"The threshold that defines (>=) a hot card.") \
\
develop(bool, G1PrintOopAppls, false, \
"When true, print applications of closures to external locs.") \
\
develop(intx, G1RSetRegionEntriesBase, 256, \
"Max number of regions in a fine-grain table per MB.") \
\
product(intx, G1RSetRegionEntries, 0, \
"Max number of regions for which we keep bitmaps." \
"Will be set ergonomically by default") \
\
develop(intx, G1RSetSparseRegionEntriesBase, 4, \
"Max number of entries per region in a sparse table " \
"per MB.") \
\
product(intx, G1RSetSparseRegionEntries, 0, \
"Max number of entries per region in a sparse table." \
"Will be set ergonomically by default.") \
\
develop(bool, G1RecordHRRSOops, false, \
"When true, record recent calls to rem set operations.") \
\
develop(bool, G1RecordHRRSEvents, false, \
"When true, record recent calls to rem set operations.") \
\
develop(intx, G1MaxVerifyFailures, -1, \
"The maximum number of verification failrues to print. " \
"-1 means print all.") \
\
develop(bool, G1ScrubRemSets, true, \
"When true, do RS scrubbing after cleanup.") \
\
develop(bool, G1RSScrubVerbose, false, \
"When true, do RS scrubbing with verbose output.") \
\
develop(bool, G1YoungSurvRateVerbose, false, \
"print out the survival rate of young regions according to age.") \
\
develop(intx, G1YoungSurvRateNumRegionsSummary, 0, \
"the number of regions for which we'll print a surv rate " \
"summary.") \
\
product(intx, G1ReservePercent, 10, \
"It determines the minimum reserve we should have in the heap " \
"to minimize the probability of promotion failure.") \
\
diagnostic(bool, G1PrintHeapRegions, false, \
"If set G1 will print information on which regions are being " \
"allocated and which are reclaimed.") \
\
develop(bool, G1HRRSUseSparseTable, true, \
"When true, use sparse table to save space.") \
\
develop(bool, G1HRRSFlushLogBuffersOnVerify, false, \
"Forces flushing of log buffers before verification.") \
\
develop(bool, G1FailOnFPError, false, \
"When set, G1 will fail when it encounters an FP 'error', " \
"so as to allow debugging") \
\
develop(bool, G1FixedTenuringThreshold, false, \
"When set, G1 will not adjust the tenuring threshold") \
\
develop(bool, G1FixedEdenSize, false, \
"When set, G1 will not allocate unused survivor space regions") \
\
develop(uintx, G1FixedSurvivorSpaceSize, 0, \
"If non-0 is the size of the G1 survivor space, " \
"otherwise SurvivorRatio is used to determine the size") \
\
product(uintx, G1HeapRegionSize, 0, \
"Size of the G1 regions.") \
\
experimental(bool, G1UseParallelRSetUpdating, true, \
"Enables the parallelization of remembered set updating " \
"during evacuation pauses") \
\
experimental(bool, G1UseParallelRSetScanning, true, \
"Enables the parallelization of remembered set scanning " \
"during evacuation pauses") \
\
product(uintx, G1ConcRefinementThreads, 0, \
"If non-0 is the number of parallel rem set update threads, " \
"otherwise the value is determined ergonomically.") \
\
develop(intx, G1CardCountCacheExpandThreshold, 16, \
"Expand the card count cache if the number of collisions for " \
"a particular entry exceeds this value.") \
\
develop(bool, G1VerifyCTCleanup, false, \
"Verify card table cleanup.") \
\
product(uintx, G1RSetScanBlockSize, 64, \
"Size of a work unit of cards claimed by a worker thread" \
"during RSet scanning.") \
\
develop(bool, ReduceInitialCardMarksForG1, false, \
"When ReduceInitialCardMarks is true, this flag setting " \
" controls whether G1 allows the RICM optimization")
G1_FLAGS(DECLARE_DEVELOPER_FLAG, DECLARE_PD_DEVELOPER_FLAG, DECLARE_PRODUCT_FLAG, DECLARE_PD_PRODUCT_FLAG, DECLARE_DIAGNOSTIC_FLAG, DECLARE_EXPERIMENTAL_FLAG, DECLARE_NOTPRODUCT_FLAG, DECLARE_MANAGEABLE_FLAG, DECLARE_PRODUCT_RW_FLAG)
#endif // SHARE_VM_GC_IMPLEMENTATION_G1_G1_GLOBALS_HPP