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SubjectRe: [PATCH] x86: clean up vdso-layout.lds.S
Roland McGrath wrote:
>
> You mean this one:
>
> /*
> * Align the actual code well away from the non-instruction data.
> * This is the best thing for the I-cache.
> */
> . = ALIGN(0x100);
>
> Reading the comment might make it obvious that it's intended for optimal
> code alignment. I suspect someone at the time told me 256 is as big as an
> I-cache line was ever likely to get. You could use L1_CACHE_BYTES instead
> I suppose.
>

Most likely 256 was chosen as a compromise between the the
then-documented value for coherency avoidance (128), future-proofing,
and waste.

I don't think we want to use different values on different platforms,
and end up with dramatically different vdsos when they still need to fit
in the same size envelope.

-hpa

--
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel. I don't speak on their behalf.



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