Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756409AbaBRQVS (ORCPT ); Tue, 18 Feb 2014 11:21:18 -0500 Received: from qmta13.emeryville.ca.mail.comcast.net ([76.96.27.243]:55442 "EHLO qmta13.emeryville.ca.mail.comcast.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755715AbaBRQVN (ORCPT ); Tue, 18 Feb 2014 11:21:13 -0500 Date: Tue, 18 Feb 2014 10:21:10 -0600 (CST) From: Christoph Lameter X-X-Sender: cl@nuc To: Joonsoo Kim cc: Pekka Enberg , Andrew Morton , David Rientjes , Wanpeng Li , linux-mm@kvack.org, linux-kernel@vger.kernel.org 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: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: 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 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/