From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: 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 9F5DAB7112 for ; Tue, 23 Jun 2009 08:04:01 +1000 (EST) Received: from bedivere.hansenpartnership.com (bedivere.hansenpartnership.com [66.63.167.143]) by ozlabs.org (Postfix) with ESMTP id 5DFF7DDD0C for ; Tue, 23 Jun 2009 08:04:01 +1000 (EST) Subject: Re: Boot failure on the powerstation with 2.6.30 latest From: James Bottomley To: Brian King In-Reply-To: <4A3FAD31.2060703@linux.vnet.ibm.com> References: <1245683801.6901.8.camel@mulgrave.site> <4A3FAD31.2060703@linux.vnet.ibm.com> Content-Type: text/plain Date: Mon, 22 Jun 2009 17:03:56 -0500 Message-Id: <1245708236.17035.2.camel@mulgrave.site> Mime-Version: 1.0 Cc: linuxppc-dev@ozlabs.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Mon, 2009-06-22 at 11:11 -0500, Brian King wrote: > James, > > I was running into a similar hang on one of my Power boxes as well. > Reverting c868d550115b9ccc0027c67265b9520790f05601 allowed by system > to boot. It looks like that patch injected a bug where we can end up > waiting on an uninitialized mutex: > > [c0000000009f3c30] c00000000052c7dc .mutex_lock+0x34/0x50 > [c0000000009f3cb0] c00000000008b190 .get_online_cpus+0x3c/0x74 > [c0000000009f3d40] c000000000146cd0 .kmem_cache_create+0xcc/0x548 > [c0000000009f3e50] c000000000032ae0 .pgtable_cache_init+0x28/0x6c > [c0000000009f3ee0] c000000000780960 .start_kernel+0x1ec/0x520 > [c0000000009f3f90] c0000000000083d8 .start_here_common+0x1c/0x44 > > The mutex gets initialized in cpu_hotplug_init, which doesn't get called until > after pgtable_cache_init. Actually, no, reverting that one doesn't fix it. A full run of git bisect turns up this commit as the culprit; I'll make a fuss on lkml: 83b519e8b9572c319c8e0c615ee5dd7272856090 is first bad commit commit 83b519e8b9572c319c8e0c615ee5dd7272856090 Author: Pekka Enberg Date: Wed Jun 10 19:40:04 2009 +0300 slab: setup allocators earlier in the boot sequence James