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SubjectRe: RFC: remove __read_mostly
On Thu, Dec 13, 2007 at 11:20:44PM +0100, Adrian Bunk wrote:
> Is there anywhere in the kernel a case where __read_mostly brings a
> measurable improvement or can it be removed?
>

Yes, definitely[1]... the problem is, and this is also true of other
annotations[2], that people go absolutely nuts adding these annotations
without doing any profiling to see whether they actually improve things.

I'd bet, in the __read_mostly case at least, that there's no
improvement in almost all cases.

cheers, Kyle

1. It's hugely relevant on big-SMP machines.
2. I mean __read_mostly, likely, unlikely, etc., not the useful sparse
annotations.


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