Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757457AbZLONrj (ORCPT ); Tue, 15 Dec 2009 08:47:39 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755932AbZLONrh (ORCPT ); Tue, 15 Dec 2009 08:47:37 -0500 Received: from e23smtp03.au.ibm.com ([202.81.31.145]:49708 "EHLO e23smtp03.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755344AbZLONrg (ORCPT ); Tue, 15 Dec 2009 08:47:36 -0500 Message-ID: <4B279370.5050800@in.ibm.com> Date: Tue, 15 Dec 2009 19:17:28 +0530 From: Sachin Sant User-Agent: Thunderbird 2.0.0.22 (X11/20090609) MIME-Version: 1.0 To: Peter Zijlstra CC: Benjamin Herrenschmidt , Linux/PPC Development , linux-kernel , Ingo Molnar , linux-next@vger.kernel.org Subject: Re: [Next] CPU Hotplug test failures on powerpc References: <4B2224C7.1020908@in.ibm.com> <1260786122.4165.142.camel@twins> <4B261D7A.9040802@in.ibm.com> <1260793182.4165.223.camel@twins> <1260825420.2217.40.camel@pasglop> <4B275A6B.9030200@in.ibm.com> <1260873827.4165.362.camel@twins> In-Reply-To: <1260873827.4165.362.camel@twins> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3300 Lines: 91 Peter Zijlstra wrote: >> I added some debug statements within the above code. >> This is a 2 cpu machine. >> >> XMON dest_cpu = 1024 . dead_cpu = 1 . nr_cpu_ids = 2 >> XMON dest_cpu = 1024 >> XMON dest_cpu = 1024 . dead_cpu = 1 >> XMON dest_cpu = 1024 . dead_cpu = 1 . nr_cpu_ids = 2 >> XMON dest_cpu = 1024 >> XMON dest_cpu = 1024 . dead_cpu = 1 >> XMON dest_cpu = 1024 . dead_cpu = 1 . nr_cpu_ids = 2 >> XMON dest_cpu = 1024 >> XMON dest_cpu = 1024 . dead_cpu = 1 >> >> Seems to me that the control is stuck in an infinite loop and hence the >> machine appears to be in hung state. The dest_cpu value is always 1024 >> and never changes, which result in an infinite loop. >> >> In working scenario the o/p is something on the following lines >> >> XMON dest_cpu = 1024 . dead_cpu = 1 . nr_cpu_ids = 2 >> XMON dest_cpu = 0 >> XMON dest_cpu = 1024 . dead_cpu = 1 . nr_cpu_ids = 2 >> XMON dest_cpu = 0 >> XMON dest_cpu = 1024 . dead_cpu = 1 . nr_cpu_ids = 2 >> XMON dest_cpu = 0 >> >> Let me know if i should try to record any specific value ? >> > > Could you possibly print the two masks themselves? cpumask_scnprintf() > and friend come in handy for this. > > The dest_cpu=1024 thing seem to suggest the intersection between > p->cpus_allowed and cpu_active_mask is empty for some reason, even > though we forcefully reset p->cpus_allowed to the full set using > cpuset_cpus_allowed_locked(). > So here is the data related to the two masks. cpu_active_mask = 00000000,00000000,00000000,00000000,00000000,00000000, 00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000, 00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000, 00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000, 00000000,00000000 XMON dest_cpu = 1024 while p->cpus_allowed = 00000000,00000000,00000000,00000000,00000000, 00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000, 00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000, 00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000, 00000000,00000000,00000001 XMON dest_cpu = 1024 In working scenario the above data looks like cpu_active_mask = 00000000,00000000,00000000,00000000,00000000,00000000, 00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000, 00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000, 00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000, 00000000,00000002 XMON dest_cpu = 1 while p->cpus_allowed = 00000000,00000000,00000000,00000000,00000000, 00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000, 00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000, 00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000, 00000000,00000000,00000002 XMON dest_cpu = 1 hope i got the data correct. Thanks -Sachin -- --------------------------------- Sachin Sant IBM Linux Technology Center India Systems and Technology Labs Bangalore, India --------------------------------- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/