JaCoLine - Viewing Historical Command Line #6617

Analysis Date	JDK	Operating System	CPU Architecture	Debug JVM?
2023-01-10	OpenJDK19	Linux	x86	N

Results

Switches Identified

-Xms2g

-Xmx16g

-XX:+UnlockExperimentalVMOptions

-XX:+UnlockDiagnosticVMOptions

-XX:+AlwaysActAsServerClassMachine

-XX:+AlwaysPreTouch

-XX:+DisableExplicitGC

-XX:+UseNUMA

-XX:NmethodSweepActivity=1

-XX:-DontCompileHugeMethods

-XX:+PerfDisableSharedMem

-XX:+UseFastUnorderedTimeStamps

-XX:+UseCriticalJavaThreadPriority

-XX:AllocatePrefetchStyle=3

-XX:+UseG1GC

-XX:MaxGCPauseMillis=37

-XX:G1HeapRegionSize=16M

-XX:G1NewSizePercent=23

-XX:G1ReservePercent=20

-XX:SurvivorRatio=32

-XX:G1MixedGCCountTarget=3

-XX:G1HeapWastePercent=20

-XX:InitiatingHeapOccupancyPercent=10

-XX:MaxTenuringThreshold=1

-XX:G1SATBBufferEnqueueingThresholdPercent=30

-XX:G1ConcMarkStepDurationMillis=5.0

-XX:G1ConcRSHotCardLimit=16

-XX:G1ConcRefinementServiceIntervalMillis=150

-XX:GCTimeRatio=99

Switch Analysis

Name	Type	Description	Default Value	Your Value
ms	<size>	set initial Java heap size		2g
Analysis	OK

Name	Type	Description	Default Value	Your Value
mx	<size>	set maximum Java heap size		16g
Analysis	OK

Name	Type	Description	Default Value	Your Value
UnlockExperimentalVMOptions	boolean	Enable normal processing of flags relating to experimental features	false	true
Analysis	OK

Name	Type	Description	Default Value	Your Value
UnlockDiagnosticVMOptions	boolean	Enable normal processing of flags relating to field diagnostics	trueInDebug	true
Analysis	OK

Name	Type	Description	Default Value	Your Value
AlwaysActAsServerClassMachine	boolean	Always act like a server-class machine	false	true
Analysis	OK

Name	Type	Description	Default Value	Your Value
AlwaysPreTouch	boolean	Force all freshly committed pages to be pre-touched	false	true
Analysis	OK

Name	Type	Description	Default Value	Your Value
DisableExplicitGC	boolean	Ignore calls to System.gc()	false	true
Analysis	OK

Name	Type	Description	Default Value	Your Value
UseNUMA	boolean	Use NUMA if available	false	true
Analysis	OK

Name	Type	Description	Default Value	Your Value
NmethodSweepActivity	int	Removes cold nmethods from code cache if > 0. Higher values result in more aggressive sweeping	10 in range(0, 2000)	1
Analysis	OK

Name	Type	Description	Default Value	Your Value
DontCompileHugeMethods	boolean	Do not compile methods > HugeMethodLimit	true	false
Analysis	OK

Name	Type	Description	Default Value	Your Value
PerfDisableSharedMem	boolean	Store performance data in standard memory	false	true
Analysis	OK

Name	Type	Description	Default Value	Your Value
UseFastUnorderedTimeStamps	boolean	Use platform unstable time where supported for timestamps only	false	true
Analysis	OK

Name	Type	Description	Default Value	Your Value
UseCriticalJavaThreadPriority	boolean	Java thread priority 10 maps to critical scheduling priority	false	true
Analysis	OK

Name	Type	Description	Default Value	Your Value
AlignVector	boolean	Perform vector store/load alignment in loop	true	true
Analysis	OK

Name	Type	Description	Default Value	Your Value
OptoBundling	boolean	Generate nops to fill i-cache lines	false	true
Analysis	OK

Name	Type	Description	Default Value	Your Value
OptoScheduling	boolean	Instruction Scheduling after register allocation	false	true
Analysis	OK

Name	Type	Description	Default Value	Your Value
OptimizeFill	boolean	convert fill/copy loops into intrinsic	true PPC64_ONLY(&& false)	true
Analysis	OK

Name	Type	Description	Default Value	Your Value
AllocatePrefetchStyle	int	0 = no prefetch, 1 = generate prefetch instructions for each allocation, 2 = use TLAB watermark to gate allocation prefetch, 3 = generate one prefetch instruction per cache line	1 in range(0, 3)	3
Analysis	OK

Name	Type	Description	Default Value	Your Value
UseG1GC	boolean	Use the Garbage-First garbage collector	false	true
Analysis	OK

Name	Type	Description	Default Value	Your Value
MaxGCPauseMillis	int	Adaptive size policy maximum GC pause time goal in millisecond, or (G1 Only) the maximum GC time per MMU time slice	max_uintx - 1 in range(1, max_uintx - 1)	37
Analysis	OK

Name	Type	Description	Default Value	Your Value
G1HeapRegionSize	size_t	Size of the G1 regions.	0 in range(0, NOT_LP64(32M) LP64_ONLY(512M))	16M
Analysis	OK

Name	Type	Description	Default Value	Your Value
G1NewSizePercent	int	Percentage (0-100) of the heap size to use as default minimum young gen size.	5 in range(0, 100)	23
Analysis	OK

Name	Type	Description	Default Value	Your Value
G1ReservePercent	int	It determines the minimum reserve we should have in the heap to minimize the probability of promotion failure.	10 in range(0, 50)	20
Analysis	OK

Name	Type	Description	Default Value	Your Value
SurvivorRatio	int	Ratio of eden/survivor space size	8 in range(1, max_uintx-2)	32
Analysis	OK

Name	Type	Description	Default Value	Your Value
G1MixedGCCountTarget	int	The target number of mixed GCs after a marking cycle.	8 in range(0, max_uintx)	3
Analysis	OK

Name	Type	Description	Default Value	Your Value
G1HeapWastePercent	int	Amount of space, expressed as a percentage of the heap size, that G1 is willing not to collect to avoid expensive GCs.	5 in range(0, 100)	20
Analysis	OK

Name	Type	Description	Default Value	Your Value
InitiatingHeapOccupancyPercent	int	The percent occupancy (IHOP) of the current old generation capacity above which a concurrent mark cycle will be initiated Its value may change over time if adaptive IHOP is enabled, otherwise the value remains constant. In the latter case a value of 0 will result as frequent as possible concurrent marking cycles. A value of 100 disables concurrent marking. Fragmentation waste in the old generation is not considered free space in this calculation. (G1 collector only)	45 in range(0, 100)	10
Analysis	OK

Name	Type	Description	Default Value	Your Value
MaxTenuringThreshold	int	Maximum value for tenuring threshold	15 in range(0, markWord::max_age + 1)	1
Analysis	OK

Name	Type	Description	Default Value	Your Value
G1SATBBufferEnqueueingThresholdPercent	int	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.	60 in range(0, 100)	30
Analysis	OK

Name	Type	Description	Default Value	Your Value
G1ConcMarkStepDurationMillis	double	Target duration of individual concurrent marking steps in milliseconds.	10.0 in range(1.0, DBL_MAX)	5.0
Analysis	OK

Name	Type	Description	Default Value	Your Value
G1ConcRSHotCardLimit	int	The threshold that defines (>=) a hot card.	4 in range(0, max_jubyte)	16
Analysis	This switch will be removed in the future. It will be Obsoleted in OpenJDK21. Expired in OpenJDK24.

Name	Type	Description	Default Value	Your Value
G1ConcRefinementServiceIntervalMillis	int	The G1 service thread wakes up every specified number of milliseconds to do miscellaneous work.	300 in range(0, max_jint)	150
Analysis	This switch will be removed in the future. It will be Obsoleted in OpenJDK20. Expired in OpenJDK24.

Name	Type	Description	Default Value	Your Value
GCTimeRatio	int	Adaptive size policy application time to GC time ratio	99 in range(0, max_juint)	99
Analysis	OK