Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759550AbXFBDmG (ORCPT ); Fri, 1 Jun 2007 23:42:06 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755252AbXFBDl4 (ORCPT ); Fri, 1 Jun 2007 23:41:56 -0400 Received: from smtp2.linux-foundation.org ([207.189.120.14]:53853 "EHLO smtp2.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755249AbXFBDl4 (ORCPT ); Fri, 1 Jun 2007 23:41:56 -0400 Date: Fri, 1 Jun 2007 20:41:41 -0700 From: Andrew Morton To: Christoph Lameter Cc: linux-kernel@vger.kernel.org, torvalds@linux-foundation.org, jeremy@goop.org Subject: Re: SLUB: Return ZERO_SIZE_PTR for kmalloc(0) Message-Id: <20070601204141.f84ad72f.akpm@linux-foundation.org> In-Reply-To: References: X-Mailer: Sylpheed 2.4.1 (GTK+ 2.8.17; x86_64-unknown-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 622 Lines: 14 > On Fri, 1 Jun 2007 18:37:46 -0700 (PDT) Christoph Lameter wrote: > > +#define ZERO_SIZE_PTR ((void *)16) Jeremy's point was a good one. The kernel _does_ use address-comparison to determine object-inequality in an unknown but non-zero number of places. It is of course unlikely that this will occur in conjunction with zero-sized objects, but who knows? - 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/