Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753095AbbHMOde (ORCPT ); Thu, 13 Aug 2015 10:33:34 -0400 Received: from verein.lst.de ([213.95.11.211]:48737 "EHLO newverein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752474AbbHMOd2 (ORCPT ); Thu, 13 Aug 2015 10:33:28 -0400 Date: Thu, 13 Aug 2015 16:33:25 +0200 From: Christoph Hellwig To: Linus Torvalds Cc: Christoph Hellwig , Jens Axboe , Dan Williams , Vineet Gupta , =?iso-8859-1?Q?H=E5vard?= Skinnemoen , Hans-Christian Egtvedt , Miao Steven , David Howells , Michal Simek , the arch/x86 maintainers , David Woodhouse , Alex Williamson , grundler@parisc-linux.org, Linux Kernel Mailing List , "linux-arch@vger.kernel.org" , linux-alpha@vger.kernel.org, "linux-ia64@vger.kernel.org" , linux-metag@vger.kernel.org, linux-mips , Parisc List , ppc-dev , linux-s390 , sparclinux@vger.kernel.org, linux-xtensa@linux-xtensa.org, "linux-nvdimm@lists.01.org" , Linux Media Mailing List Subject: Re: [PATCH 31/31] dma-mapping-common: skip kmemleak checks for page-less SG entries Message-ID: <20150813143325.GB17183@lst.de> References: <1439363150-8661-1-git-send-email-hch@lst.de> <1439363150-8661-32-git-send-email-hch@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 830 Lines: 19 On Wed, Aug 12, 2015 at 09:05:15AM -0700, Linus Torvalds wrote: > [ Again, I'm responding to one random patch - this pattern was in > other patches too. ] > > A question: do we actually expect to mix page-less and pageful SG > entries in the same SG list? > > How does that happen? Both for DAX and the video buffer case people could do direct I/O spanning the boundary between such a VMA and a normal one unless we add special code to prevent that. Right now I don't think it's all that useful, but then again it doesn't seem harmful either and adding those checks might add up. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/