From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e28smtp03.in.ibm.com (e28smtp03.in.ibm.com [59.145.155.3]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "e28smtp03.in.ibm.com", Issuer "Equifax" (verified OK)) by ozlabs.org (Postfix) with ESMTPS id D9E56DDDA5 for ; Wed, 1 Apr 2009 17:40:16 +1100 (EST) Received: from d28relay04.in.ibm.com (d28relay04.in.ibm.com [9.184.220.61]) by e28smtp03.in.ibm.com (8.13.1/8.13.1) with ESMTP id n316eAqY013506 for ; Wed, 1 Apr 2009 12:10:10 +0530 Received: from d28av01.in.ibm.com (d28av01.in.ibm.com [9.184.220.63]) by d28relay04.in.ibm.com (8.13.8/8.13.8/NCO v9.2) with ESMTP id n316eJNJ3690718 for ; Wed, 1 Apr 2009 12:10:19 +0530 Received: from d28av01.in.ibm.com (loopback [127.0.0.1]) by d28av01.in.ibm.com (8.13.1/8.13.3) with ESMTP id n316e9mP009329 for ; Wed, 1 Apr 2009 12:10:10 +0530 Message-ID: <49D30C48.4090902@in.ibm.com> Date: Wed, 01 Apr 2009 12:10:08 +0530 From: Sachin Sant MIME-Version: 1.0 To: Benjamin Herrenschmidt Subject: Re: [ppc64] 2.6.29-git7 : offlining a cpu causes an exception References: <49D1E21E.3090505@in.ibm.com> <1238539469.17330.70.camel@pasglop> In-Reply-To: <1238539469.17330.70.camel@pasglop> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Cc: linuxppc-dev@ozlabs.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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 ? > I don't get any other messages when the problem occurs. Infact if i don't have xmon enabled the machine just hangs without any messages on the console. I extracted the dmesg log (attached in my previous mail) through xmon. Here are last few related messages from 2.6.29-git8 kernel during problem recreation. <4>IRQ 18 affinity broken off cpu 2 <4>cpu 2 (hwid 2) Ready to die.... <7>CPU0 attaching NULL sched-domain.. <7>CPU1 attaching NULL sched-domain.. <7>CPU2 attaching NULL sched-domain.. <7>CPU3 attaching NULL sched-domain.. <7>CPU0 attaching sched-domain:. <7> domain 0: span 0-1 level SIBLING. <7> groups: 0 1. <7> domain 1: span 0-1,3 level CPU. <7> groups: 0-1 3. <7> domain 2: span 0-1,3 level NODE <7> groups: 0-1,3. <7>CPU1 attaching sched-domain:. <7> domain 0: span 0-1 level SIBLING. <7> groups: 1 0. <7> domain 1: span 0-1,3 level CPU. <7> groups: 0-1 3. <7> domain 2: span 0-1,3 level NODE. <7> groups: 0-1,3. <7>CPU3 attaching sched-domain:. <7> domain 0: span 0-1,3 level CPU. <7> groups: 3 0-1. <7> domain 1: span 0-1,3 level NODE. <7> groups: 0-1,3... > That or lookup where the PC and LR values are in System.map > and maybe get us a backtrace from xmon ? > > (You seem to have no symbols, have you built with kallsyms ?) I have kallsyms and debug info options enabled. CONFIG_KALLSYMS=y CONFIG_KALLSYMS_ALL=y # CONFIG_KALLSYMS_EXTRA_PASS is not set CONFIG_DEBUG_INFO=y Here is the related information from 2.6.29-git8 kernel. llm62 login: cpu 0x2: Vector: 700 (Program Check) at [c0000000074c7ca0] pc: 00000000007b6640 lr: 000000000079ddc0 sp: c0000000074c7f20 msr: 8000000000081002 current = 0xc0000000fe1c8580 paca = 0xc000000000ab2800 pid = 0, comm = swapper enter ? for help [c0000000074c7f20] 0000000000018694 (unreliable) [c0000000074c7f90] 0000000000008278 SP (4f00000003) is in userspace 2:mon> la %pc 00000000007b6640 2:mon> la c0000000007b6640 c0000000007b6640: .kmem_cache_init+0x2d8/0x528 2:mon> la %lr 000000000079ddc0 2:mon> la c00000000079ddc0 c00000000079ddc0: .mem_init+0x150/0x22c 2:mon> Regards -Sachin -- --------------------------------- Sachin Sant IBM Linux Technology Center India Systems and Technology Labs Bangalore, India ---------------------------------