Re: DMA memory, split_page, BUG_ON(PageCompound()), sound

From: Marc Singer
Date: Mon Jul 10 2006 - 18:25:27 EST


On Tue, Jul 11, 2006 at 03:34:11AM +1000, Nick Piggin wrote:
> Russell King wrote:
> >On Mon, Jul 10, 2006 at 04:59:48PM +1000, Nick Piggin wrote:
> >
> >>I guess you could do it a number of ways. Maybe having GFP_USERMAP
> >>set __GFP_USERMAP|__GFP_COMP, and the arm dma memory allocator can
> >>strip the __GFP_COMP.
> >>
> >>If you get an explicit __GFP_COMP passed down, the allocator doesn't
> >>know whether that was because they want a user mappable area, or
> >>really want a compound page (in which case, stripping __GFP_COMP is
> >>the wrong thing to do).
> >
> >
> >So I'll mask off __GFP_COMP for the time being in the ARM dma allocator
> >with a note to this effect?
>
> I believe that should do the trick, yes (AFAIK, nobody yet is
> explicitly relying on a compound page from the dma allocator).
>
> Marc can hopefully confim the fix.

I'll verify that that works, yes.

>
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