circlee/performance_option.tsv

## performance_option.tsv

          
            Option and Default Value
            Description

            
              -XX:+AggressiveOpts
              Turn on point performance compiler optimizations that are expected to be default in upcoming releases. (Introduced in 5.0 update 6.)

            
              -XX:CompileThreshold=10000
              Number of method invocations/branches before compiling [-client: 1,500]

            
              -XX:LargePageSizeInBytes=4m
              Sets the large page size used for the Java heap. (Introduced in 1.4.0 update 1.) [amd64: 2m.]

            
              -XX:MaxHeapFreeRatio=70
              Maximum percentage of heap free after GC to avoid shrinking.

            
              -XX:MaxNewSize=size
              Maximum size of new generation (in bytes). Since 1.4, MaxNewSize is computed as a function of NewRatio. [1.3.1 Sparc: 32m; 1.3.1 x86: 2.5m.]

            
              -XX:MaxPermSize=64m
              Size of the Permanent Generation.  [5.0 and newer: 64 bit VMs are scaled 30% larger; 1.4 amd64: 96m; 1.3.1 -client: 32m.]

            
              -XX:MinHeapFreeRatio=40
              Minimum percentage of heap free after GC to avoid expansion.

            
              -XX:NewRatio=2
              Ratio of old/new generation sizes. [Sparc -client: 8; x86 -server: 8; x86 -client: 12.]-client: 4 (1.3) 8 (1.3.1+), x86: 12]

            
              -XX:NewSize=2m
              Default size of new generation (in bytes) [5.0 and newer: 64 bit VMs are scaled 30% larger; x86: 1m; x86, 5.0 and older: 640k]

            
              -XX:ReservedCodeCacheSize=32m
              Reserved code cache size (in bytes) - maximum code cache size. [Solaris 64-bit, amd64, and -server x86: 2048m; in 1.5.0_06 and earlier, Solaris 64-bit and amd64: 1024m.]

            
              -XX:SurvivorRatio=8
              Ratio of eden/survivor space size [Solaris amd64: 6; Sparc in 1.3.1: 25; other Solaris platforms in 5.0 and earlier: 32]

            
              -XX:TargetSurvivorRatio=50
              Desired percentage of survivor space used after scavenge.

            
              -XX:ThreadStackSize=512
              Thread Stack Size (in Kbytes). (0 means use default stack size) [Sparc: 512; Solaris x86: 320 (was 256 prior in 5.0 and earlier); Sparc 64 bit: 1024; Linux amd64: 1024 (was 0 in 5.0 and earlier); all others 0.]

            
              -XX:+UseBiasedLocking
              Enable biased locking. For more details, see this tuning example. (Introduced in 5.0 update 6.) [5.0: false]

            
              -XX:+UseFastAccessorMethods
              Use optimized versions of Get<Primitive>Field.

            
              -XX:-UseISM
              Use Intimate Shared Memory. [Not accepted for non-Solaris platforms.] For details, see Intimate Shared Memory.

            
              -XX:+UseLargePages
              Use large page memory. (Introduced in 5.0 update 5.) For details, see Java Support for Large Memory Pages.

            
              -XX:+UseMPSS
              Use Multiple Page Size Support w/4mb pages for the heap. Do not use with ISM as this replaces the need for ISM. (Introduced in 1.4.0 update 1, Relevant to Solaris 9 and newer.) [1.4.1 and earlier: false]

            
              -XX:+UseStringCache
              Enables caching of commonly allocated strings.

            
              -XX:AllocatePrefetchLines=1
              Number of cache lines to load after the last object allocation using prefetch instructions generated in JIT compiled code. Default values are 1 if the last allocated object was an instance and 3 if it was an array.

            
              -XX:AllocatePrefetchStyle=1
              Generated code style for prefetch instructions. 0 - no prefetch instructions are generate*d*, 1 - execute prefetch instructions after each allocation, 2 - use TLAB allocation watermark pointer to gate when prefetch instructions are executed.

            
              -XX:+UseCompressedStrings
              Use a byte[] for Strings which can be represented as pure ASCII. (Introduced in Java 6 Update 21 Performance Release)

            
              -XX:+OptimizeStringConcat
              Optimize String concatenation operations where possible. (Introduced in Java 6 Update 20)
	Option and Default Value	Description
	-XX:+AggressiveOpts	Turn on point performance compiler optimizations that are expected to be default in upcoming releases. (Introduced in 5.0 update 6.)
	-XX:CompileThreshold=10000	Number of method invocations/branches before compiling [-client: 1,500]
	-XX:LargePageSizeInBytes=4m	Sets the large page size used for the Java heap. (Introduced in 1.4.0 update 1.) [amd64: 2m.]
	-XX:MaxHeapFreeRatio=70	Maximum percentage of heap free after GC to avoid shrinking.
	-XX:MaxNewSize=size	Maximum size of new generation (in bytes). Since 1.4, MaxNewSize is computed as a function of NewRatio. [1.3.1 Sparc: 32m; 1.3.1 x86: 2.5m.]
	-XX:MaxPermSize=64m	Size of the Permanent Generation. [5.0 and newer: 64 bit VMs are scaled 30% larger; 1.4 amd64: 96m; 1.3.1 -client: 32m.]
	-XX:MinHeapFreeRatio=40	Minimum percentage of heap free after GC to avoid expansion.
	-XX:NewRatio=2	Ratio of old/new generation sizes. [Sparc -client: 8; x86 -server: 8; x86 -client: 12.]-client: 4 (1.3) 8 (1.3.1+), x86: 12]
	-XX:NewSize=2m	Default size of new generation (in bytes) [5.0 and newer: 64 bit VMs are scaled 30% larger; x86: 1m; x86, 5.0 and older: 640k]
	-XX:ReservedCodeCacheSize=32m	Reserved code cache size (in bytes) - maximum code cache size. [Solaris 64-bit, amd64, and -server x86: 2048m; in 1.5.0_06 and earlier, Solaris 64-bit and amd64: 1024m.]
	-XX:SurvivorRatio=8	Ratio of eden/survivor space size [Solaris amd64: 6; Sparc in 1.3.1: 25; other Solaris platforms in 5.0 and earlier: 32]
	-XX:TargetSurvivorRatio=50	Desired percentage of survivor space used after scavenge.
	-XX:ThreadStackSize=512	Thread Stack Size (in Kbytes). (0 means use default stack size) [Sparc: 512; Solaris x86: 320 (was 256 prior in 5.0 and earlier); Sparc 64 bit: 1024; Linux amd64: 1024 (was 0 in 5.0 and earlier); all others 0.]
	-XX:+UseBiasedLocking	Enable biased locking. For more details, see this tuning example. (Introduced in 5.0 update 6.) [5.0: false]
	-XX:+UseFastAccessorMethods	Use optimized versions of Get<Primitive>Field.
	-XX:-UseISM	Use Intimate Shared Memory. [Not accepted for non-Solaris platforms.] For details, see Intimate Shared Memory.
	-XX:+UseLargePages	Use large page memory. (Introduced in 5.0 update 5.) For details, see Java Support for Large Memory Pages.
	-XX:+UseMPSS	Use Multiple Page Size Support w/4mb pages for the heap. Do not use with ISM as this replaces the need for ISM. (Introduced in 1.4.0 update 1, Relevant to Solaris 9 and newer.) [1.4.1 and earlier: false]
	-XX:+UseStringCache	Enables caching of commonly allocated strings.
	-XX:AllocatePrefetchLines=1	Number of cache lines to load after the last object allocation using prefetch instructions generated in JIT compiled code. Default values are 1 if the last allocated object was an instance and 3 if it was an array.
	-XX:AllocatePrefetchStyle=1	Generated code style for prefetch instructions. 0 - no prefetch instructions are generated, 1 - execute prefetch instructions after each allocation, 2 - use TLAB allocation watermark pointer to gate when prefetch instructions are executed.
	-XX:+UseCompressedStrings	Use a byte[] for Strings which can be represented as pure ASCII. (Introduced in Java 6 Update 21 Performance Release)
	-XX:+OptimizeStringConcat	Optimize String concatenation operations where possible. (Introduced in Java 6 Update 20)