Re: getting processor numbers

[H. Peter Anvin]

Eric Dumazet wrote:
> There is one thing that always worried me.
>
> Intel & AMD manuals make clear that mixing data and program in the same 
> page is bad for performance.
>
> In particular, x86_64 vsyscall put jiffies and other 
> vsyscall_gtod_data_t right in the midle of code. That is certainly not 
> wise.
>
> A probably sane implementation should use two pages, one for code, one 
> for data.

Mutable data should be separated from code.  I think any current CPU 
will do fine as long as they are in separate 128-byte chunks, but they 
need at least that much separation.

Readonly data does not need to be separated from code.

	-hpa
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