On Wednesday 11 October 2006 03:46, Geoff Levand wrote:
> >
> > The others look good, but this one complicates the code and doesn't have
> > any benefit. 20
> > for 21 isn't bad.
>
> Is the motivation for this change to improve performance by reducing the
> overhead
> of the mapping calls? If so, there may be some benefit for some systems.
> Could
> you please elaborate?
>
>From what I understand, this patch drastically reduces the number of
I/O PTEs that are needed in the iommu. With the current static IOMMU
mapping, it should only make a difference during initialization, but
any platform that uses a dynamic mapping of iommu entries will benefit
a lot from it, because:
- the card can do better prefetching of consecutive memory
- there are more I/O ptes available for other drivers.
Arnd <><
-
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at http://vger.kernel.org/majordomo-info.html
