From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S266474AbUIELqZ (ORCPT ); Sun, 5 Sep 2004 07:46:25 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S263770AbUIELqY (ORCPT ); Sun, 5 Sep 2004 07:46:24 -0400 Received: from mx2.elte.hu ([157.181.151.9]:49081 "EHLO mx2.elte.hu") by vger.kernel.org with ESMTP id S266474AbUIELpK (ORCPT ); Sun, 5 Sep 2004 07:45:10 -0400 Date: Sun, 5 Sep 2004 13:46:45 +0200 From: Ingo Molnar To: William Lee Irwin III , Andrew Morton , James Bottomley , Jesse Barnes , Linus Torvalds , Nick Piggin , linux-kernel@vger.kernel.org Subject: Re: [sched] fix sched_domains hotplug bootstrap ordering vs. cpu_online_map issue Message-ID: <20040905114645.GA11422@elte.hu> References: <1094246465.1712.12.camel@mulgrave> <20040903145925.1e7aedd3.akpm@osdl.org> <20040903222212.GV3106@holomorphy.com> <20040903153434.15719192.akpm@osdl.org> <20040903224507.GX3106@holomorphy.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20040903224507.GX3106@holomorphy.com> User-Agent: Mutt/1.4.1i X-ELTE-SpamVersion: MailScanner 4.31.6-itk1 (ELTE 1.2) SpamAssassin 2.63 ClamAV 0.73 X-ELTE-VirusStatus: clean X-ELTE-SpamCheck: no X-ELTE-SpamCheck-Details: score=-4.9, required 5.9, autolearn=not spam, BAYES_00 -4.90 X-ELTE-SpamLevel: X-ELTE-SpamScore: -4 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org * William Lee Irwin III wrote: > William Lee Irwin III wrote: > >> This is the whole thing; the "other half" referred to a new hunk added to > >> the patch (identical to this one) posted in its entirety. > > On Fri, Sep 03, 2004 at 03:34:34PM -0700, Andrew Morton wrote: > > ho-hum. changelog, please? > > cpu_online_map is not set up at the time of sched domain > initialization when hotplug cpu paths are used for SMP booting. At > this phase of bootstrapping, cpu_possible_map can be used by the > various architectures using cpu hotplugging for SMP bootstrap, but the > manipulations of cpu_online_map done on behalf of NUMA architectures, > done indirectly via node_to_cpumask(), can't, because cpu_online_map > starts depopulated and hasn't yet been populated. On true NUMA > architectures this is a distinct cpumask_t from cpu_online_map and so > the unpatched code works on NUMA; on non-NUMA architectures the > definition of node_to_cpumask() this way breaks and would require an > invasive sweeping of users of node_to_cpumask() to change it to e.g. > cpu_possible_map, as cpu_possible_map is not suitable for use at > runtime as a substitute for cpu_online_map. > > Signed-off-by: William Irwin Signed-off-by: Ingo Molnar Ingo