Per-process address space in RHEL x86_64?
 

I am having trouble finding a definitive answer to this question. Can someone tell me what the per-process address space is in RHEL3 ES and RHEL4 ES on the x86_64 architecture?

/usr/src/linux-2.4/Documentation/x86_64/mm.txt suggests that the address space is 512GB. Can someone confirm that? Is this true for both RHEL3 ES and RHEL4 ES?

Also, is the limit on the size of a shared memory segment 1GB in x86_64 on RHEL3 ES and RHEL4 ES?

Thanks!