Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935315AbdCWPnO (ORCPT ); Thu, 23 Mar 2017 11:43:14 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:34208 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753202AbdCWPnN (ORCPT ); Thu, 23 Mar 2017 11:43:13 -0400 Date: Thu, 23 Mar 2017 21:12:29 +0530 From: Vaidyanathan Srinivasan To: "Rafael J. Wysocki" Cc: Michael Neuling , Michael Ellerman , "Rafael J . Wysocki" , Daniel Lezcano , linuxppc-dev , Linux Kernel Mailing List , Linux PM Subject: Re: [PATCH v2 1/2] powerpc/powernv/cpuidle: Pass correct drv->cpumask for registration Reply-To: svaidy@linux.vnet.ibm.com References: <20170323152247.14733-1-svaidy@linux.vnet.ibm.com> <20170323152247.14733-2-svaidy@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.8.0 (2017-02-23) X-TM-AS-MML: disable x-cbid: 17032315-0032-0000-0000-000002015AFB X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17032315-0033-0000-0000-0000123576F0 Message-Id: <20170323154229.GB9058@drishya.in.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2017-03-23_13:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=0 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1702020001 definitions=main-1703230139 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2944 Lines: 63 * Rafael J. Wysocki [2017-03-23 16:28:31]: > On Thu, Mar 23, 2017 at 4:22 PM, Vaidyanathan Srinivasan > wrote: > > drv->cpumask defaults to cpu_possible_mask in __cpuidle_driver_init(). > > On PowerNV platform cpu_present could be less than cpu_possible in cases > > where firmware detects the cpu, but it is not available to the OS. When > > CONFIG_HOTPLUG_CPU=n, such cpus are not hotplugable at runtime and hence > > we skip creating cpu_device. > > > > This breaks cpuidle on powernv where register_cpu() is not called for > > cpus in cpu_possible_mask that cannot be hot-added at runtime. > > > > Trying cpuidle_register_device() on cpu without cpu_device will cause > > crash like this: > > > > cpu 0xf: Vector: 380 (Data SLB Access) at [c000000ff1503490] > > pc: c00000000022c8bc: string+0x34/0x60 > > lr: c00000000022ed78: vsnprintf+0x284/0x42c > > sp: c000000ff1503710 > > msr: 9000000000009033 > > dar: 6000000060000000 > > current = 0xc000000ff1480000 > > paca = 0xc00000000fe82d00 softe: 0 irq_happened: 0x01 > > pid = 1, comm = swapper/8 > > Linux version 4.11.0-rc2 (sv@sagarika) (gcc version 4.9.4 > > (Buildroot 2017.02-00004-gc28573e) ) #15 SMP Fri Mar 17 19:32:02 IST 2017 > > enter ? for help > > [link register ] c00000000022ed78 vsnprintf+0x284/0x42c > > [c000000ff1503710] c00000000022ebb8 vsnprintf+0xc4/0x42c (unreliable) > > [c000000ff1503800] c00000000022ef40 vscnprintf+0x20/0x44 > > [c000000ff1503830] c0000000000ab61c vprintk_emit+0x94/0x2cc > > [c000000ff15038a0] c0000000000acc9c vprintk_func+0x60/0x74 > > [c000000ff15038c0] c000000000619694 printk+0x38/0x4c > > [c000000ff15038e0] c000000000224950 kobject_get+0x40/0x60 > > [c000000ff1503950] c00000000022507c kobject_add_internal+0x60/0x2c4 > > [c000000ff15039e0] c000000000225350 kobject_init_and_add+0x70/0x78 > > [c000000ff1503a60] c00000000053c288 cpuidle_add_sysfs+0x9c/0xe0 > > [c000000ff1503ae0] c00000000053aeac cpuidle_register_device+0xd4/0x12c > > [c000000ff1503b30] c00000000053b108 cpuidle_register+0x98/0xcc > > [c000000ff1503bc0] c00000000085eaf0 powernv_processor_idle_init+0x140/0x1e0 > > [c000000ff1503c60] c00000000000cd60 do_one_initcall+0xc0/0x15c > > [c000000ff1503d20] c000000000833e84 kernel_init_freeable+0x1a0/0x25c > > [c000000ff1503dc0] c00000000000d478 kernel_init+0x24/0x12c > > [c000000ff1503e30] c00000000000b564 ret_from_kernel_thread+0x5c/0x78 > > > > This patch fixes the bug by passing correct cpumask from > > powernv-cpuidle driver. > > > > Signed-off-by: Vaidyanathan Srinivasan > > That needs to be ACKed by someone familiar with powernv. Previous version at https://lists.ozlabs.org/pipermail/linuxppc-dev/2017-March/155587.html I had not CCed linux-pm in the first post. Michael and Mikey have reviewed the previous version. Let me get an ack for you to proceed with the merge. Thanks, Vaidy