On Fri, Jan 17, 2014 at 08:34:38AM +0900, Akinobu Mita wrote: > 2014/1/16 Konrad Rzeszutek Wilk <konrad.w...@oracle.com>: > > On Tue, Jan 14, 2014 at 11:13:46PM +0900, Akinobu Mita wrote: > >> Calling dma_alloc_coherent() with __GFP_ZERO must return zeroed memory. > >> > >> But when the contiguous memory allocator (CMA) is enabled on x86 and > >> the memory region is allocated by dma_alloc_from_contiguous(), it > >> doesn't return zeroed memory. Because dma_generic_alloc_coherent() > > > > So why not fix it there to return zeroed out memory? > > I thought it looked nicer than this patch as we can remove memset > from all caller of dma_alloc_from_contiguous(). But if I look at > the caller on arm, we can't simply remove the memset because > __dma_clear_buffer() is used there for ensuring cache flushing and > it is used in many places.
OK, that should be part of the commit description. > > Of course we can do redundant memset in dma_alloc_from_contiguous(), > but now I think this patch is less impact for fixing this problem. OK. _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
