From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756129AbZHYTkT (ORCPT ); Tue, 25 Aug 2009 15:40:19 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755845AbZHYTkS (ORCPT ); Tue, 25 Aug 2009 15:40:18 -0400 Received: from mail-ew0-f206.google.com ([209.85.219.206]:61416 "EHLO mail-ew0-f206.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756016AbZHYTkR (ORCPT ); Tue, 25 Aug 2009 15:40:17 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=date:from:to:cc:subject:message-id:references:mime-version :content-type:content-disposition:in-reply-to:user-agent; b=LiQP/wBS7kd5iMN5/STxNqGwWsdNvsW1dxh+6IKSLXlSt3D7X5HrtvuYw75hQt+oBf 9QVM8ZRPpzDPx5D9EQGP8oe/cdtgrql2ej8DHwbNWqQJNfFbM1WQsE85hWlMdnhrm4y5 rRtHzCuKEpSdqSuq5K0zX1d3Yv4ngSbZVWcQc= Date: Tue, 25 Aug 2009 23:40:11 +0400 From: Cyrill Gorcunov To: Ravikiran G Thirumalai Cc: Ingo Molnar , Yinghai Lu , torvalds@linux-foundation.org, linux-kernel@vger.kernel.org, shai@scalex86.org, Suresh Siddha Subject: Re: [patch] x86: 2.6.31-rc7 crash due to buggy flat_phys_pkg_id Message-ID: <20090825194011.GD5806@lenovo> References: <20090824182659.GA6842@localdomain> <4A932809.1000103@kernel.org> <20090825012632.GB6842@localdomain> <4A9372A1.9090905@kernel.org> <20090825171716.GC6456@localdomain> <20090825181500.GB3277@elte.hu> <20090825183130.GA5806@lenovo> <20090825192055.GD6456@localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20090825192055.GD6456@localdomain> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org [Ravikiran G Thirumalai - Tue, Aug 25, 2009 at 12:20:55PM -0700] | On Tue, Aug 25, 2009 at 10:31:30PM +0400, Cyrill Gorcunov wrote: | >[Ingo Molnar - Tue, Aug 25, 2009 at 08:15:00PM +0200] | >| | > | >I'm definitely not APIC expert but since I was partially involved | >letme turn in. | > | >Original commit which causes problem for vSMP seems to be due | >to cpu_has_apic bit turned off (ie due to being manually disabled | >or acpi table broken) so further read apic id will return plain | >zero (we're talking about 64 bits now). So frnakly I don't understand | >what is wrong with Ravikiran's patch. In case of apic disabled | >initial apic value will be used anyway (which is latched but | >actually may be changed, but it's not our case). | > | | Exactly my thinking. I hoped the patch I posted solves both cases -- | does not depend on local apic id for the "fix crash on certain UP configs" | case in the commit here: | | http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=2759c3287de27266e06f1f4e82cbd2d65f6a044c | | And fixes vsmp too. | | >Or perhaps there is an issue in srat numa nodes numbering? | > | | Don't think so, local apic id has been used for for 'flat' and 'cluster' | apic (which was used prior to 'flat') for atleast 15 major releases. | | Cyrill/Yinghai, can you test and confirm if the patch attached does not | regress the 'UP crash case' mentioned in | commit 2759c3287de27266e06f1f4e82cbd2d65f6a044c please? | | --- | I would like to but I can;t. I don;t even know where were we hanging at this crash case. I was only reading commit changelog and since it was said about "not apic bit set" I thought about disabled apic case. Personally I like much more quirk Yinghai posted which leaves phys id function _bared_ and simple as it should be :) And since it's too late before kernel release -- introducing read apic back seems to be dangerous I suppose: there are a number of configs which could be having side effect. At moment they are tested _with_ Yinghai patch and only vSMP is issued. Though the problem need to be investigated more closely. But I'm not knowing that much in this area. -- Cyrill