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SubjectRe: [PATCH] x86_64/__iowrite32_copy: don't use string move for PIO writes
"H. Peter Anvin" <hpa@zytor.com> wrote:

> John Gregor wrote:
> > From: John Gregor <johng@diamond.mv.qlogic.com>
> >
> > Some processors can write the same word more than once if the movs
> > instruction is used. This version uses normal memory move instructions
> > and gets the same performance since the speed is limited by PCIe and
> > write combining.
> >
>
> Which processors do that *when addressing I/O memory*?

More specifically, check out:

http://www.intel.com/Assets/PDF/specupdate/321324.pdf

Errata AAK6

-John Gregor


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