From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932468AbWFUHcE (ORCPT ); Wed, 21 Jun 2006 03:32:04 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932470AbWFUHcE (ORCPT ); Wed, 21 Jun 2006 03:32:04 -0400 Received: from canuck.infradead.org ([205.233.218.70]:690 "EHLO canuck.infradead.org") by vger.kernel.org with ESMTP id S932468AbWFUHcC (ORCPT ); Wed, 21 Jun 2006 03:32:02 -0400 Subject: Re: cfq-iosched.c:RB_CLEAR_COLOR From: David Woodhouse To: Linus Torvalds Cc: David Miller , linux-kernel@vger.kernel.org, akpm@osdl.org, Jens Axboe In-Reply-To: References: <20060620.173434.35660839.davem@davemloft.net> Content-Type: text/plain Date: Wed, 21 Jun 2006 08:31:53 +0100 Message-Id: <1150875113.3176.506.camel@pmac.infradead.org> Mime-Version: 1.0 X-Mailer: Evolution 2.6.2 (2.6.2-1.fc5.1.dwmw2.2) Content-Transfer-Encoding: 7bit X-SRS-Rewrite: SMTP reverse-path rewritten from by canuck.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2006-06-20 at 18:03 -0700, Linus Torvalds wrote: > > There were two explicit calls in the cfq-iosched.c file > > to RB_CLEAR_COLOR, only the one in cfq_del_crq_rb() got > > removed so the build fails. Apologies for that; the new one got added only last week, and escaped my attention. > I think the right fix is to just remove the RB_CLEAR_COLOR() call, since > the memset will set everything to 0/NULL, which should be the correct > initialization these days anyway. > > David (the other one - dwmw2), pls confirm? Yes, that looks correct. Other code, including the AS scheduler, was (ab)using the colour field by storing a 'RB_NONE' value which was neither red nor black to mark an 'off-tree' node, then checking for it with ON_RB(). I changed that scheme -- we now set the node's parent pointer to point to itself to mark an off-tree node. However, the cfq scheduler looks like it only inherited the macros from AS, and was never actually _checking_ if a given node was on-tree or not. So just dropping the magic initialisation stuff there is fine. -- dwmw2