Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933808AbYBGXcl (ORCPT ); Thu, 7 Feb 2008 18:32:41 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757496AbYBGXcb (ORCPT ); Thu, 7 Feb 2008 18:32:31 -0500 Received: from relay1.sgi.com ([192.48.171.29]:45363 "EHLO relay.sgi.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1756946AbYBGXca (ORCPT ); Thu, 7 Feb 2008 18:32:30 -0500 Date: Thu, 7 Feb 2008 15:32:29 -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: <19f34abd0802071518j1ffc3dafp46fcbd8d36d36f17@mail.gmail.com> Message-ID: References: <47AB79D4.2070605@gmail.com> <19f34abd0802071412m569e4993kffb4a3af163fa16c@mail.gmail.com> <19f34abd0802071518j1ffc3dafp46fcbd8d36d36f17@mail.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: 1113 Lines: 23 On Fri, 8 Feb 2008, Vegard Nossum wrote: > The tracking that kmemcheck does is actually a byte-for-byte tracking > of whether memory has been initialized or not. Think of it as valgrind > for the kernel. We do this by "hiding" pages (marking them non-present > for for MMU) and taking the page faults, which effectively tells us > what memory is being attempted to be read from or written to. Ahh. Okay. But ZONE_DMA pages are exempt from that scheme? You know that ZONE_NORMAL pages can undergo dma? > I chose to implement this in the slab layer because this is probably > where most of the interesting allocations are coming from, and this > gives us a better control over what most users/callers care about, > namely the specific objects. But the slab layer allocates pages < PAGE_SIZE. You need to take a fault right? So each object would need its own page? -- 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/