Two questions about compressed references

[Alex Aisinzon]

Hi all

 

I had two questions about the use of compressed references:

*         I understand that, with compressed references, the native
memory must be located within a 32 bit space (which may be as small as
2GB on Windows). Additionally, if the heap is small enough and can
function in "real" 32 bit, the heap will be placed in the 32 bit space,
thereby reducing the space available for the native memory. As a result,
out of native memory issues are more likely. I have heard of an option
to rebase the heap above that 32 bit space so as to provide more growth
to the native memory. Does someone know of that option?

*         I understand how compressed references work for the heap (Java
addresses are 8 bytes aligned and, therefore, addresses have the least 3
bits set to 0, which allows a address up to 35 bit to be stored in 32
bit after some shifting). I am less clear on how compressed references
works for the native memory: does it use a 32 bit pointer only or does
it use a 64 bit one?

 

Thanks in advance

 

Alex Aisinzon

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