On Wed, Jul 01, 2015 at 12:12:51PM +0100, Catalin Marinas wrote: > On Tue, Jun 30, 2015 at 11:29:06PM +0200, Lorenzo Nava wrote: > > This patch allows the use of CMA for DMA coherent memory allocation. > > At the moment if the input parameter "is_coherent" is set to true > > the allocation is not made using the CMA, which I think is not the > > desired behaviour. > > > > Signed-off-by: Lorenzo Nava <lore...@gmail.com> > > Reviewed-by: Catalin Marinas <catalin.mari...@arm.com> > > If Russell doesn't have any objections, you can send the patch to > his patch system. See here for more information:
I'm left wondering whether this patch is really want Lorenzo wants. >From my reading of it, while this has the effect of allocating from CMA for coherent devices, it's no different from the non-coherent case, because by calling __alloc_from_contiguous(), we end up remapping the allocated memory, removing the cacheability status from the allocated pages. This brings up an interesting point: presumably, it's been tested, and people are happy with the performance it's giving, inspite of it not returning cacheable memory... or maybe it hasn't been tested that much? -- FTTC broadband for 0.8mile line: currently at 10.5Mbps down 400kbps up according to speedtest.net. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
