hi.

On Tue, 2002-02-12 at 16:48, Russell King wrote:
> On Tue, Feb 12, 2002 at 04:36:34PM +0100, Daniel Stodden wrote:
> > ARM does GFP_KERNEL, and then __ioremaps the underlying pages.
> > ugh. is that the only way to get the area coherent?
> 
> Yes.  Cache bits are in the page tables, and it would be idiotic to
> manipulate the cache bits on a 1MB granularity over the kernel
> direct mapped space.
> 
> > furthermore i don't see why this could not be interrupt safe.
> 
> GFP_KERNEL in the page table allocation functions mainly.  We've been
> around and around this recently on this mailing list, so I'm not going
> to say anything further.  I don't want another long discussion about
> this subject taking my time away from doing real work on ARM.  If you're
> really interested in the outcome, please examine the lkml archives.

ok. i read part of the old thread now. sorry. didn't know that this had
already been issued.

so, based on the fact that
1. _most_ archs can easily do atomically.
2. those which don't aren't necessarily the better ones.
3. many drivers may prefer/be able to alloc through during
   _init()/_release()
3.5 some may not.
4. even on arm, __ioremap() takes a gfp for quite some time now 
   and nobody seems to disagree.

then why does pci_alloc_consistent() not just take gfp flags and people
put in what their personal preference is?

regards,
dns


-- 
___________________________________________________________________________
 mailto:stodden@in.tum.de