Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755686Ab0KLI3l (ORCPT ); Fri, 12 Nov 2010 03:29:41 -0500 Received: from zene.cmpxchg.org ([85.214.230.12]:37016 "EHLO zene.cmpxchg.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752809Ab0KLI3l (ORCPT ); Fri, 12 Nov 2010 03:29:41 -0500 Date: Fri, 12 Nov 2010 09:29:21 +0100 From: Johannes Weiner To: Greg Thelen Cc: Andrew Morton , Balbir Singh , KAMEZAWA Hiroyuki , Daisuke Nishimura , Wu Fengguang , Minchan Kim , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 6/6] memcg: make mem_cgroup_page_stat() return value unsigned Message-ID: <20101112082921.GH9131@cmpxchg.org> References: <1289294671-6865-1-git-send-email-gthelen@google.com> <1289294671-6865-7-git-send-email-gthelen@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1289294671-6865-7-git-send-email-gthelen@google.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 887 Lines: 23 On Tue, Nov 09, 2010 at 01:24:31AM -0800, Greg Thelen wrote: > mem_cgroup_page_stat() used to return a negative page count > value to indicate value. Whoops :) > mem_cgroup_page_stat() has changed so it never returns > error so convert the return value to the traditional page > count type (unsigned long). This changelog feels a bit beside the point. What's really interesting is that we now don't consider negative sums to be invalid anymore, but just assume zero! There is a real semantical change here. That the return type can then be changed to unsigned long is a nice follow-up cleanup that happens to be folded into this patch. -- 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/