From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756383Ab1KISEO (ORCPT ); Wed, 9 Nov 2011 13:04:14 -0500 Received: from hqemgate04.nvidia.com ([216.228.121.35]:8522 "EHLO hqemgate04.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756004Ab1KISEN convert rfc822-to-8bit (ORCPT ); Wed, 9 Nov 2011 13:04:13 -0500 X-PGP-Universal: processed; by hqnvupgp06.nvidia.com on Wed, 09 Nov 2011 10:03:47 -0800 From: Stephen Warren To: Russell King CC: Jon Medhurst , Nicolas Pitre , "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" , Sumit Bhattacharya Date: Wed, 9 Nov 2011 10:03:46 -0800 Subject: RE: [PATCH] arm: dma: Drop GFP_COMP for DMA memory allocations Thread-Topic: [PATCH] arm: dma: Drop GFP_COMP for DMA memory allocations Thread-Index: AcybOcLVon/rnySgQNGSWjC4H8zhFAD0AWBA Message-ID: <74CDBE0F657A3D45AFBB94109FB122FF174080512F@HQMAIL01.nvidia.com> References: <1320442539-7753-1-git-send-email-swarren@nvidia.com> In-Reply-To: <1320442539-7753-1-git-send-email-swarren@nvidia.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: acceptlanguage: en-US Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 > Tested-by: Varun Colbert > [swarren: s/HUGETLB_PAGE/HUGETLBFS/ in comment, minor comment cleanup] > Signed-off-by: Stephen Warren 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