Messages in this thread | | | From | Stephen Warren <> | Date | Wed, 9 Nov 2011 10:03:46 -0800 | Subject | RE: [PATCH] arm: dma: Drop GFP_COMP for DMA memory allocations |
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Stephen Warren wrote at Friday, November 04, 2011 3:36 PM: > dma_alloc_coherent wants to split pages after allocation in order to > reduce the memory footprint. This does not work well with GFP_COMP > pages, so drop this flag before allocation. > > This patch is ported from arch/avr32 > (commit 3611553ef985ef7c5863c8a94641738addd04cff). > > Signed-off-by: Sumit Bhattacharya <sumitb@nvidia.com> > Tested-by: Varun Colbert <vcolbert@nvidia.com> > [swarren: s/HUGETLB_PAGE/HUGETLBFS/ in comment, minor comment cleanup] > Signed-off-by: Stephen Warren <swarren@nvidia.com>
Russell, does this look good to go in the patch system now?
> --- > arch/arm/mm/dma-mapping.c | 9 +++++++++ > 1 files changed, 9 insertions(+), 0 deletions(-) > > diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c > index e4e7f6c..68d64b4 100644 > --- a/arch/arm/mm/dma-mapping.c > +++ b/arch/arm/mm/dma-mapping.c > @@ -332,6 +332,15 @@ __dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp, > struct page *page; > void *addr; > > + /* > + * Following is a work-around (a.k.a. hack) to prevent pages > + * with __GFP_COMP being passed to split_page() which cannot > + * handle them. The real problem is that this flag probably > + * should be 0 on ARM as it is not supported on this > + * platform; see CONFIG_HUGETLBFS. > + */ > + gfp &= ~(__GFP_COMP); > + > *handle = ~0; > size = PAGE_ALIGN(size); > > -- > 1.7.0.4
-- nvpublic
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