Re: memcpy_toio on i386 using byte writes even when n%2==0

[H. Peter Anvin]

Robert Hancock wrote:
> H. Peter Anvin wrote:
> > For something that generates I/O transactions, it's imperative to
> > generate the smallest possible number of transactions.  Furthermore,
> > smaller than dword transactions aren't burstable, except at the
> > beginning and end of a burst.
>
> Well, theoretically for writes they could be, if the memory region was 
> prefetchable and the PCI chipset supported byte merge. It certainly 
> isn't optimal however.

If so, then merging doesn't matter either way.

	-hpa
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