Re: [RFC 00/15] x86_64: Optimize percpu accesses

From: Mike Travis
Date: Wed Jul 09 2008 - 14:14:48 EST


Jeremy Fitzhardinge wrote:
...
>
> Once the pda has shrunk as much as it can (which remove everything
> except stack_canary, I think), then remove all the X_pda macros, since
> there won't be any users anyway.
>
> J

You bring up a good point here. Since the stack_canary has to be 20
(or is that 0x20?) bytes from %gs, then it sounds like we'll still
need a pda struct of some sort. And zero padding before that seems
counter-productive, so perhaps taking a poll of the most used pda
(or percpu) variables and keeping them in the same cache line would
be more useful?

Thanks,
Mike
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