Messages in this thread | | | Date | Thu, 28 May 2009 09:54:16 +0200 | From | Andi Kleen <> | Subject | Re: [PATCH] [1/16] HWPOISON: Add page flag for poisoned pages |
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On Wed, May 27, 2009 at 10:15:10PM +0100, Alan Cox wrote: > On Wed, 27 May 2009 22:12:26 +0200 (CEST) > Andi Kleen <andi@firstfloor.org> wrote: > > > > > Hardware poisoned pages need special handling in the VM and shouldn't be > > touched again. This requires a new page flag. Define it here. > > Why can't you use PG_reserved ? That already indicates the page may not > even be present (which is effectively your situation at that point).
Right now a page must be present with PG_reserved, otherwise /dev/mem, /proc/kcore lots of other things will explode.
> Given lots of other hardware platforms we support bus error, machine > check, explode or do random undefined fun things when you touch pages > that don't exist I'm not sure I see why poisoned is different here ?
It's really a special case for lots of things and mixing it up with PG_reserved is not very useful I think. Also page flags are not that tight a resource anymore anyways. I think it's better to have it separated.
However I would expect that other architectures would use poisoned pages too for their own similar issues. It's not really a x86 specific concept.
-Andi
-- ak@linux.intel.com -- Speaking for myself only.
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