Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754133Ab0GMINT (ORCPT ); Tue, 13 Jul 2010 04:13:19 -0400 Received: from earthlight.etchedpixels.co.uk ([81.2.110.250]:57568 "EHLO www.etchedpixels.co.uk" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753482Ab0GMINO (ORCPT ); Tue, 13 Jul 2010 04:13:14 -0400 Date: Tue, 13 Jul 2010 09:20:12 +0100 From: Alan Cox To: FUJITA Tomonori Cc: zpfeffer@codeaurora.org, joro@8bytes.org, dwalker@codeaurora.org, andi@firstfloor.org, randy.dunlap@oracle.com, mel@csn.ul.ie, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: Re: [RFC 3/3] mm: iommu: The Virtual Contiguous Memory Manager Message-ID: <20100713092012.7c1fe53e@lxorguk.ukuu.org.uk> In-Reply-To: <20100713145852C.fujita.tomonori@lab.ntt.co.jp> References: <4C2D965F.5000206@codeaurora.org> <20100710145639.GC10080@8bytes.org> <4C3BFDD3.8040209@codeaurora.org> <20100713145852C.fujita.tomonori@lab.ntt.co.jp> X-Mailer: Claws Mail 3.7.6 (GTK+ 2.18.9; x86_64-redhat-linux-gnu) Face: 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 Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 757 Lines: 18 > Why video4linux can't use the DMA API? Doing DMA with vmalloc'ed > buffers is a thing that we should avoid (there are some exceptions > like xfs though). Vmalloc is about the only API for creating virtually linear memory areas. The video stuff really needs that to avoid lots of horrible special cases when doing buffer processing and the like. Pretty much each driver using it has a pair of functions 'rvmalloc' and 'rvfree' so given a proper "vmalloc_for_dma()" type interface can easily be switched Alan -- 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/