What is the NQFSEA_STACK_ALLOC JIT option?
 Technote (FAQ)
 
Problem
The NQFSEA_STACK_ALLOC option is used to turn off stack allocation of objects during one of the JIT optimizations called Escape Analysis.
 
Solution
The NQFSEA_STACK_ALLOC option is used to turn off Stack allocation of objects during a JIT optimization called Escape Analysis. In Escape Analysis, the JVM determines if an object has escaped the context of a method. If it hasn't, then JVM proceeds to allocate the object itself on the stack as opposed to a reference to the object.

When NQFSEA_STACK_ALLOC is set, the JVM prevents allocation of the objects on the stack. If a crash is due to an object field on the stack getting corrupted, then the problem would be circumvented with this option.

Setting this option would mean disabling a JIT optimization. There is likely to be a performance impact, but it would have much less impact than turning off JIT completely.
 
 
Cross Reference information
Segment Product Component Platform Version Edition
Application Servers Runtimes for Java Technology Java SDK
 
 


Document Information


Product categories: Software > Application Servers > Distributed Application & Web Servers > WebSphere Application Server > Java SDK
Operating system(s): Windows
Software version: 6.0
Software edition:
Reference #: 1203465
IBM Group: Software Group
Modified date: Sep 2, 2007