| Option and Default Value 
 | Description | 
						
								| -XX:-AllowUserSignalHandlers | Do not complain if the application installs signal handlers. (Relevant to Solaris and Linux only.) 
 
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								| -XX:AltStackSize=16384 | Alternate signal stack size (in Kbytes). (Relevant to Solaris only, removed from 5.0.) 
 
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								| -XX:-DisableExplicitGC | Disable calls to System.gc(), JVM still performs garbage collection when necessary. 
 
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								| -XX:+FailOverToOldVerifier | Fail over to old verifier when the new type checker fails. (Introduced in 6.) 
 
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								| -XX:+HandlePromotionFailure | The youngest generation collection does not require a guarantee of full promotion of all live objects. (Introduced in 1.4.2 update 11) [5.0 and earlier: false.] 
 
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								| -XX:+MaxFDLimit | Bump the number of file descriptors to max. (Relevant  to Solaris only.) 
 
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								| -XX:PreBlockSpin=10 | Spin count variable for use with -XX:+UseSpinning. Controls the maximum spin iterations allowed before entering operating system thread synchronization code. (Introduced in 1.4.2.) 
 
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								| -XX:-RelaxAccessControlCheck | Relax the access control checks in the verifier. (Introduced in 6.) 
 
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								| -XX:+ScavengeBeforeFullGC | Do young generation GC prior to a full GC. (Introduced in 1.4.1.) 
 
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								| -XX:+UseAltSigs | Use alternate signals instead of SIGUSR1 and SIGUSR2 for VM internal signals. (Introduced in 1.3.1 update 9, 1.4.1. Relevant to Solaris only.) 
 
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								| -XX:+UseBoundThreads | Bind user level threads to kernel threads. (Relevant to Solaris only.) 
 
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								| -XX:-UseConcMarkSweepGC | Use concurrent mark-sweep collection for the old generation. (Introduced in 1.4.1) 
 
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								| -XX:+UseGCOverheadLimit | Use a policy that limits the proportion of the VM's time that is spent in GC before an OutOfMemory error is thrown. (Introduced in 6.) 
 
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								| -XX:+UseLWPSynchronization | Use LWP-based instead of thread based synchronization. (Introduced in 1.4.0. Relevant to Solaris only.) 
 
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								| -XX:-UseParallelGC | Use parallel garbage collection for scavenges. (Introduced in 1.4.1) 
 
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								| -XX:-UseParallelOldGC | Use parallel garbage collection for the full collections. Enabling this option automatically sets -XX:+UseParallelGC. (Introduced in 5.0 update 6.) 
 
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								| -XX:-UseSerialGC | Use serial garbage collection. (Introduced in 5.0.) 
 
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								| -XX:-UseSpinning | Enable naive spinning on Java monitor before entering operating system thread synchronizaton code. (Relevant to 1.4.2 and 5.0 only.) [1.4.2, multi-processor Windows platforms: true] 
 
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								| -XX:+UseTLAB | Use thread-local object allocation (Introduced in 1.4.0, known as UseTLE prior to that.) [1.4.2 and earlier, x86 or with -client: false] 
 
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								| -XX:+UseSplitVerifier | Use the new type checker with StackMapTable attributes. (Introduced in 5.0.)[5.0: false] 
 
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								| -XX:+UseThreadPriorities | Use native thread priorities. 
 
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								| -XX:+UseVMInterruptibleIO | Thread interrupt before or with EINTR for I/O operations results in OS_INTRPT. (Introduced in 6. Relevant to Solaris only.) 
 
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