From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758880AbZBYTXr (ORCPT ); Wed, 25 Feb 2009 14:23:47 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756405AbZBYTXi (ORCPT ); Wed, 25 Feb 2009 14:23:38 -0500 Received: from mail-bw0-f178.google.com ([209.85.218.178]:34580 "EHLO mail-bw0-f178.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756017AbZBYTXh (ORCPT ); Wed, 25 Feb 2009 14:23:37 -0500 X-Greylist: delayed 337 seconds by postgrey-1.27 at vger.kernel.org; Wed, 25 Feb 2009 14:23:36 EST DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; b=xPwqrCpcrSQv2Flt3eAciHkG3WIpj9YhXFZPc9SXSQDpckAjDHqXHFWlllR/JRzg+1 REg8OXYEKG0KmoI2SQTynEa0nOm20glMxcJ/PwCs78qh7aNpY5ZF2jL8PZzCNAR9fKVB bQgIJuxPDNhUGMELA1mRfzQdrY7L7rKb4WhBM= MIME-Version: 1.0 In-Reply-To: <1235410406.6216.69.camel@penberg-laptop> References: <1235381712.6216.22.camel@penberg-laptop> <1235410406.6216.69.camel@penberg-laptop> Date: Wed, 25 Feb 2009 20:17:57 +0100 Message-ID: <19f34abd0902251117h7a4a6e9ao34e972110d8b40a1@mail.gmail.com> Subject: Re: [PATCH] kmemcheck: Disable SLUB and SLAB debugging when kmemcheck is enabled From: Vegard Nossum To: Pekka Enberg Cc: Christoph Lameter , mingo@elte.hu, linux-kernel@vger.kernel.org Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2009/2/23 Pekka Enberg : > On Mon, 2009-02-23 at 10:41 -0500, Christoph Lameter wrote: >> On Mon, 23 Feb 2009, Pekka Enberg wrote: >> >> > Enabling kmemcheck in Kconfig is a painful experience. Lets make it a >> > tad bit easier by inverting the dependencies to SLUB and SLAB debugging. >> > As kmemcheck is more powerful than slab debugging, disable the latter >> > functionality if an user enables kmemcheck. >> >> SLUB_DEBUG is fundamentally different from SLAB_DEBUG. It only includes >> the code to be able to enable debugging at runtime. It does not enable >> debugging. > > Yes, I know that but we can't really let the user enable both, slub > debugging and kmemcheck debugging, at run-time. That's why I used > SLUB_DEBUG here. It is possible. Which is why it said SLUB_DEBUG_ON to begin with. This is how it works: If slub_debug=,xyz is specified on the command line, the SLUB debugging will be used for the "xyz" cache, and kmemcheck will track the rest (all non-slub-debugged caches). So if we only disable SLUB_DEBUG_ON, then slub debugging and kmemcheck debugging can still be mixed at boot-time, but kmemcheck will take precedence unless slub_debug= is specified. Can you rethink whether SLUB_DEBUG or SLUB_DEBUG_ON is the one we really want to depend on !KMEMCHECK, and either submit a new patch or convince me that this is sufficient? Thanks! Vegard -- "The animistic metaphor of the bug that maliciously sneaked in while the programmer was not looking is intellectually dishonest as it disguises that the error is the programmer's own creation." -- E. W. Dijkstra, EWD1036