Messages in this thread | | | Date | Fri, 16 Jun 2006 17:31:12 +0200 | From | Zoltan Menyhart <> | Subject | Re: FOR REVIEW: New x86-64 vsyscall vgetcpu() |
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Andi Kleen wrote:
> That is not how user space TLS works. It usually has a base a register.
Can you please give me a real life (simplified) example?
> This means it cannot be cache colored (because you would need a static > offset) and you couldn't share task_structs on a page.
I do not see the problem. Can you explain please? E.g. the scheduler pulls a task instead of the current one. The CPU will see "current->thread_info.cpu"-s of all the tasks at the same offset anyway.
> Also you would make task_struct part of the userland ABI which > seems like a very very bad idea to me. It means we couldn't change > it anymore.
We can make some wrapper, e.g.:
user_per_cpu_var(name, offset)
"vgetcpu()" would also be added to the ABI which we couldn't change easily either.
Thanks,
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