From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e23smtp06.au.ibm.com (e23smtp06.au.ibm.com [202.81.31.148]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "e23smtp06.au.ibm.com", Issuer "Equifax" (verified OK)) by ozlabs.org (Postfix) with ESMTPS id 8BE22B6F1A for ; Wed, 16 Dec 2009 00:47:35 +1100 (EST) Received: from d23relay03.au.ibm.com (d23relay03.au.ibm.com [202.81.31.245]) by e23smtp06.au.ibm.com (8.14.3/8.13.1) with ESMTP id nBFDlNvT018595 for ; Wed, 16 Dec 2009 00:47:23 +1100 Received: from d23av02.au.ibm.com (d23av02.au.ibm.com [9.190.235.138]) by d23relay03.au.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id nBFDlWqo1732616 for ; Wed, 16 Dec 2009 00:47:32 +1100 Received: from d23av02.au.ibm.com (loopback [127.0.0.1]) by d23av02.au.ibm.com (8.14.3/8.13.1/NCO v10.0 AVout) with ESMTP id nBFDlVsk018282 for ; Wed, 16 Dec 2009 00:47:32 +1100 Message-ID: <4B279370.5050800@in.ibm.com> Date: Tue, 15 Dec 2009 19:17:28 +0530 From: Sachin Sant MIME-Version: 1.0 To: Peter Zijlstra 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 Cc: Ingo Molnar , linux-next@vger.kernel.org, linux-kernel , Linux/PPC Development List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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 ---------------------------------