Re: [PATCH 1/2]Add Variable Page Size and IA64 Support in Intel IOMMU: Generic Part

Ingo Molnar
2008-10-03T08:55:50Z

* Yu, Fenghua <fenghua.yu@intel.com> wrote:

> >What's this all about? Why do we need #ifdef CONFIG_IA64 here?
> >Doesn't x86 provide its own readq/writeq implementation?
>
> This is a comment from Bjorn.
>
> In my patch, one readq/one writeq are working faster than two
> readl/two writel on IA64. X86 uses two readl/two writel so that the
> code works on both x86 and x86-64 although Intel IOMMU only has x86-64
> version currently. dmar_readq() and dmar_writeq() are in moderate
> performance critical path.
>
> Do you think my current implementation is ok to have #ifdef
> CONFIG_IA64 here? Or I can change X86 to use readq/writeq as well or
> IA64 uses two readl/two writel for clean code?

yes, clean code is very much preferred for a small detail like this.

Ingo