[PATCH V2] arm: mm: Remove hugetlb warning from Coherent DMA allocator

Steve Capper steve.capper at linaro.org
Tue Feb 18 10:45:51 EST 2014

On Thu, Jan 16, 2014 at 10:07:43AM +0000, Steve Capper wrote:
> The Coherant DMA allocator allocates pages of high order then splits
> them up into smaller pages.
> This splitting logic would run into problems if the allocator was
> given compound pages. Thus the Coherant DMA allocator was originally
> incompatible with compound pages existing and, by extension, huge
> pages. A compile #error was put in place whenever huge pages were
> enabled.
> Compatibility with compound pages has since been introduced by the
> following commit (which merely excludes GFP_COMP pages from being
> requested by the coherant DMA allocator):
>   ea2e705 ARM: 7172/1: dma: Drop GFP_COMP for DMA memory allocations
> When huge page support was introduced to ARM, the compile #error in
> dma-mapping.c was replaced by a #warning when it should have been
> removed instead.
> This patch removes the compile #warning in dma-mapping.c when huge
> pages are enabled.
> Signed-off-by: Steve Capper <steve.capper at linaro.org>
> ---
> Changed in V2: commit message completely re-written to give a better
> justification.
> ---
>  arch/arm/mm/dma-mapping.c | 3 ---
>  1 file changed, 3 deletions(-)

Would anyone object to this going into Russell's patch system?


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