Re: Cache incoherencies

Benjamin Herrenschmidt (bh40@calva.net)
Thu, 26 Aug 1999 12:10:55 +0200


On Thu, Aug 26, 1999, Jes Sorensen <Jes.Sorensen@cern.ch> wrote:

>Ralf> There isn't a portable way to get uncached memory. But
>Ralf> GFP_UNCACHED sounds good.
>
>On the m68k we have a kernel_set_cachemode() which does the job.

I looked at it, but I still prefer allocating uncachable space rather
than setting the cache mode afterwards. Are there cases where you want to
toggle the cache mode of a given range more than once ?

I prefer avoiding walking the page tables the way it's done in
kernel_set_cachemode. Adding the GPF_UNCACHED flag seems a lot more
maintainable to me, and requires really very few changes to implement.

But, of course, I may be wrong...

-- 
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