Re: bigphysarea in 2.2

[David Mentre <David.Mentre@irisa.fr>]

"Stephen C. Tweedie" <sct@dcs.ed.ac.uk> writes:
  > me:
> >  With the new kernel memory manager, and if the defragmenting code which
> > is under development works, wouldn't it be more useful to use standard
> > kernel memory allocation. Static allocation like in bigphysarea is more
> > a work-around that a real solution.
> 
> Unfortunately, the current code simply doesn't grok areas larger than
> 128KB, and even if it did, it is unlikely that it could be made to
> work well in that case --- the existance of just one non-pagable
> allocation (slab, kmalloc, page table etc.) in any 512K block would
> render that entire region unreclaimable by the swapper.  If you need
> such large physically contiguous regions, then bigphysarea is still
> a better option.

 Ok, I have understood. The last problem is that driver using the
bigphysarea need a patched kernel. It's annoying (at least for a
production kernel). But it seems from recent discussions that a lobbying
group tries to incorporate it in the mainstream kernel. ;) I vote for
it, as this patch is more and more necessary (and because it seems to be
_the_ solution for big allocations).

Regards,
d.
-- 
 David.Mentre@irisa.fr -- Perso : http://www.irisa.fr/prive/dmentre/
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