From patchwork Thu Apr 16 08:25:06 2009 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michael Ellerman X-Patchwork-Id: 26049 Return-Path: X-Original-To: patchwork-incoming@bilbo.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from ozlabs.org (ozlabs.org [203.10.76.45]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "mx.ozlabs.org", Issuer "CA Cert Signing Authority" (verified OK)) by bilbo.ozlabs.org (Postfix) with ESMTPS id 9C0A3B6F35 for ; Thu, 16 Apr 2009 18:25:49 +1000 (EST) Received: by ozlabs.org (Postfix) id 5DDF0DE498; Thu, 16 Apr 2009 18:25:31 +1000 (EST) Delivered-To: patchwork-incoming@ozlabs.org Received: from ozlabs.org (localhost [127.0.0.1]) by ozlabs.org (Postfix) with ESMTP id 5AE1DDE497 for ; Thu, 16 Apr 2009 18:25:31 +1000 (EST) X-Original-To: linuxppc-dev@ozlabs.org Delivered-To: linuxppc-dev@ozlabs.org Received: from bilbo.ozlabs.org (bilbo.ozlabs.org [203.10.76.25]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "bilbo.ozlabs.org", Issuer "CAcert Class 3 Root" (verified OK)) by ozlabs.org (Postfix) with ESMTPS id 56D7FDDDA0 for ; Thu, 16 Apr 2009 18:25:07 +1000 (EST) Received: from [127.0.0.1] (localhost [127.0.0.1]) by bilbo.ozlabs.org (Postfix) with ESMTP id 05FA5B6F35; Thu, 16 Apr 2009 18:25:06 +1000 (EST) Subject: Re: [ppc64] 2.6.29-git7 : offlining a cpu causes an exception From: Michael Ellerman To: Sachin Sant In-Reply-To: <49E6C3F4.4080801@in.ibm.com> References: <49D1E21E.3090505@in.ibm.com> <1238539469.17330.70.camel@pasglop> <49D30C48.4090902@in.ibm.com> <49D3547E.8030200@in.ibm.com> <49E6C3F4.4080801@in.ibm.com> Date: Thu, 16 Apr 2009 18:25:06 +1000 Message-Id: <1239870306.14642.181.camel@localhost> Mime-Version: 1.0 X-Mailer: Evolution 2.24.3 Cc: linuxppc-dev@ozlabs.org X-BeenThere: linuxppc-dev@ozlabs.org X-Mailman-Version: 2.1.11 Precedence: list Reply-To: michael@ellerman.id.au List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@ozlabs.org Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@ozlabs.org On Thu, 2009-04-16 at 11:06 +0530, Sachin Sant wrote: > Sachin Sant wrote: > > Sachin Sant wrote: > >> Benjamin Herrenschmidt wrote: > >>> On Tue, 2009-03-31 at 14:57 +0530, Sachin Sant wrote: > >>> > >>>> While executing CPU HotPlug[1] tests i observed that during > >>>> every cpu offline process an exception is thrown. > >>>> > >>> > >>> Looks like a BUG_ON() to me... can you look at what other > >>> messages just before that ? > >> > > Ben, seems like the following patch is causing the cpu hotplug > > test failure. > > [PATCH 6/6] powerpc/mm: Introduce early_init_mmu() on 64-bit > > > > http://ozlabs.org/pipermail/linuxppc-dev/2009-March/069613.html > > > > If i back out this patch, i am able to offline/online cpu's > > without any issue. > I can recreate this problem with 2.6.30-rc2-git1 as well. Same BUG_ON while > running cpu hotplug tests. > > Let me know if there is any thing i can help to find a fix for this. Hi Sachin, Does this patch, on top of Ben's patch, fix it? cheers diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c index db556d2..1ade7eb 100644 --- a/arch/powerpc/mm/hash_utils_64.c +++ b/arch/powerpc/mm/hash_utils_64.c @@ -753,7 +753,7 @@ void __init early_init_mmu(void) } #ifdef CONFIG_SMP -void __init early_init_mmu_secondary(void) +void __cpuinit early_init_mmu_secondary(void) { /* Initialize hash table for that CPU */ if (!firmware_has_feature(FW_FEATURE_LPAR))