Single address space in Long mode

Combuster · **Posted:** Tue Jan 12, 2010 10:24 am

No, it works with multiple CPUs, multiple address spaces and multithreading.

jal · **Joined:** Wed Oct 31, 2007 9:09 am **Posts:** 1385

Combuster wrote:

jal wrote:

but that means the scheduler must update the MSR when switching tasks.

Not necessarily. You can just have it contain a pointer to a valid temporary stack, then update ESP manually. (instead of finding out the value for ESP, then bothering the slow WRMSR with it)

Indeed. Thanks for pointing it out.

JAL

Owen · **Posted:** Tue Jan 12, 2010 1:55 pm

The convention with syscall/sysret is to use the SWAPGS instruction and hang a "processor control block" off of the kernel's GS.

For this reason, I'm looking forward to clang & llvm maturing, because they have support for declaring a pointer off the GS segment, and therefore better optimized code.

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Single address space in Long mode

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