From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qc0-f178.google.com (mail-qc0-f178.google.com [209.85.216.178]) by kanga.kvack.org (Postfix) with ESMTP id 6AAE26B0031 for ; Tue, 18 Feb 2014 11:21:14 -0500 (EST) Received: by mail-qc0-f178.google.com with SMTP id m20so25620837qcx.37 for ; Tue, 18 Feb 2014 08:21:14 -0800 (PST) Received: from qmta13.emeryville.ca.mail.comcast.net (qmta13.emeryville.ca.mail.comcast.net. [2001:558:fe2d:44:76:96:27:243]) by mx.google.com with ESMTP id y8si4628424qci.75.2014.02.18.08.21.13 for ; Tue, 18 Feb 2014 08:21:13 -0800 (PST) Date: Tue, 18 Feb 2014 10:21:10 -0600 (CST) From: Christoph Lameter Subject: Re: [PATCH 9/9] slab: remove a useless lockdep annotation In-Reply-To: <20140217061201.GA3468@lge.com> Message-ID: References: <1392361043-22420-1-git-send-email-iamjoonsoo.kim@lge.com> <1392361043-22420-10-git-send-email-iamjoonsoo.kim@lge.com> <20140217061201.GA3468@lge.com> Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org List-ID: To: Joonsoo Kim Cc: Pekka Enberg , Andrew Morton , David Rientjes , Wanpeng Li , linux-mm@kvack.org, linux-kernel@vger.kernel.org On Mon, 17 Feb 2014, Joonsoo Kim wrote: > > Why change the BAD_ALIEN_MAGIC? > > Hello, Christoph. > > BAD_ALIEN_MAGIC is only checked by slab_set_lock_classes(). We remove this > function in this patch, so returning BAD_ALIEN_MAGIC is useless. Its not useless. The point is if there is a pointer deref then we will see this as a pointer value and know that it is realted to alien cache processing. > And, in fact, BAD_ALIEN_MAGIC is already useless, because alloc_alien_cache() > can't be called on !CONFIG_NUMA. This function is called if use_alien_caches > is positive, but on !CONFIG_NUMA, use_alien_caches is always 0. So we don't > have any chance to meet this BAD_ALIEN_MAGIC in runtime. Maybe it no longer serves a point. But note that caches may not be populated because processors/nodes are not up yet. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org