Re: d451564 breakage

From: Ingo Molnar
Date: Fri Nov 13 2009 - 18:17:36 EST



* Russell King <rmk+lkml@xxxxxxxxxxxxxxxx> wrote:

> On Fri, Nov 13, 2009 at 11:48:20PM +0100, Ingo Molnar wrote:
> >
> > * Russell King <rmk@xxxxxxxxxxxxxxxx> wrote:
> >
> > > Change:
> > >
> > > highmem: Fix debug_kmap_atomic() to also handle KM_IRQ_PTE, KM_NMI, and KM_NMI_PTE
> > >
> > > Appears to break ARM:
> > >
> > > mm/highmem.c: In function ???debug_kmap_atomic???:
> > > mm/highmem.c:436: error: ???KM_NMI??? undeclared (first use in this function)
> >
> > indeed - sorry.
> >
> > Note that debug_kmap_atomic() will be removed in v2.6.33 so i'd suggest
> > to just do the easy solution and add #ifndef dummy definitions to
> > mm/highmem.c to cover ARM - we'll remove the whole cruft for good.
>
> Actually, the following patch is probably the simplest solution.
>
> > Btw., testing sidenote: i test the ARM defconfig and it didnt break
> > there. Perhaps highmem is off in the ARM defconfig? It would be helpful
> > if the ARM defconfig enabled highmem.
>
> Given that highmem on ARM is experimental, I'd rather not have it enabled
> in too many machine defconfigs as standard just yet.
>
> However, enabling highmem on itself is not enough to show this breakage,
> you also need highmem debugging enabled.
>
> arch/arm/include/asm/kmap_types.h | 6 ++++++
> 1 files changed, 6 insertions(+), 0 deletions(-)
>
> diff --git a/arch/arm/include/asm/kmap_types.h b/arch/arm/include/asm/kmap_types.h
> index d16ec97..c019949 100644
> --- a/arch/arm/include/asm/kmap_types.h
> +++ b/arch/arm/include/asm/kmap_types.h
> @@ -22,4 +22,10 @@ enum km_type {
> KM_TYPE_NR
> };
>
> +#ifdef CONFIG_DEBUG_HIGHMEM
> +#define KM_NMI (-1)
> +#define KM_NMI_PTE (-1)
> +#define KM_IRQ_PTE (-1)
> +#endif

Please solve this in mm/highmem.c as Andrew suggested it - other
architectures could be affected as well beyond ARM.

Ingo
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