Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760994AbYBHHLG (ORCPT ); Fri, 8 Feb 2008 02:11:06 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754705AbYBHHKz (ORCPT ); Fri, 8 Feb 2008 02:10:55 -0500 Received: from relay2.sgi.com ([192.48.171.30]:33930 "EHLO relay.sgi.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1757005AbYBHHKy (ORCPT ); Fri, 8 Feb 2008 02:10:54 -0500 Date: Thu, 7 Feb 2008 23:10:01 -0800 (PST) From: Christoph Lameter X-X-Sender: clameter@schroedinger.engr.sgi.com To: Vegard Nossum cc: Linux Kernel Mailing List , Ingo Molnar , Pekka Enberg , Andi Kleen , Richard Knutsson Subject: Re: [PATCH 1/2] kmemcheck v3 In-Reply-To: <47AB79D4.2070605@gmail.com> Message-ID: References: <47AB79D4.2070605@gmail.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 920 Lines: 20 On Thu, 7 Feb 2008, Vegard Nossum wrote: > - DMA can be a problem since there's generally no way for kmemcheck to > determine when/if a chunk of memory is used for DMA. Ideally, DMA should be > allocated with untracked caches, but this requires annotation of the > drivers in question. There is a fundamental misunderstanding here: GFP_DMA allocations have nothing to do with DMA. Rather GFP_DMA means allocate memory in a special range of physical memory that is required by legacy devices that cannot use the high address bits for one or the other reason. Any regular memory can be used for DMA. Could you refactor the patch a bit? This is quite a big patch. -- 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/