Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752478AbbBYEfQ (ORCPT ); Tue, 24 Feb 2015 23:35:16 -0500 Received: from mail-pa0-f44.google.com ([209.85.220.44]:35738 "EHLO mail-pa0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751959AbbBYEfO (ORCPT ); Tue, 24 Feb 2015 23:35:14 -0500 Message-ID: <54ED50F5.5080603@linaro.org> Date: Wed, 25 Feb 2015 10:05:01 +0530 From: viresh kumar User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.4.0 MIME-Version: 1.0 To: Ethan Zhao , ethan zhao CC: Rafael Wysocki , santosh shilimkar , Linaro Kernel Mailman List , "linux-pm@vger.kernel.org" , linux-kernel , guangyu.sun@oracle.com, "sriharsha.devdas@oracle.com" Subject: Re: [PATCH Resend] cpufreq: Set cpufreq_cpu_data to NULL before putting kobject References: <54CEECF7.7020504@oracle.com> <54CEF123.5050106@oracle.com> <54CEF574.6040404@oracle.com> <54CEF7AA.80401@oracle.com> <54CEFA23.7040705@oracle.com> <54CF0106.5050601@oracle.com> <54CF9209.1050403@oracle.com> In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4371 Lines: 91 On Wednesday 25 February 2015 08:54 AM, Ethan Zhao wrote: > Viresh, > With this patch applied, still got the following warning and panic, > seems it needs more care. > > 54.474618] ------------[ cut here ]------------ > [ 54.545816] WARNING: CPU: 0 PID: 213 at include/linux/kref.h:47 > kobject_get+0x41/0x50() > [ 54.642595] Modules linked in: i2c_i801(+) mfd_core shpchp(+) > acpi_cpufreq(+) edac_core ioatdma(+) xfs libcrc32c ast syscopyarea ixgbe > sysfillrect sysimgblt sr_mod sd_mod drm_kms_helper igb mdio cdrom e1000e ahci > dca ttm libahci uas drm i2c_algo_bit ptp megaraid_sas libata usb_storage > i2c_core pps_core dm_mirror dm_region_hash dm_log dm_mod > [ 55.007264] CPU: 0 PID: 213 Comm: kworker/0:2 Not tainted > 3.18.5 > [ 55.099970] Hardware name: Oracle Corporation SUN FIRE X4170 M2 SERVER > /ASSY,MOTHERBOARD,X4170, BIOS 08120104 05/08/2012 > [ 55.239736] Workqueue: kacpi_notify acpi_os_execute_deferred > [ 55.308598] 0000000000000000 00000000bd730b61 ffff88046742baf8 > ffffffff816b7edb > [ 55.398305] 0000000000000000 0000000000000000 ffff88046742bb38 > ffffffff81078ae1 > [ 55.488040] ffff88046742bbd8 ffff8806706b3000 0000000000000292 > 0000000000000000 > [ 55.577776] Call Trace: > [ 55.608228] [] dump_stack+0x46/0x58 > [ 55.670895] [] warn_slowpath_common+0x81/0xa0 > [ 55.743952] [] warn_slowpath_null+0x1a/0x20 > [ 55.814929] [] kobject_get+0x41/0x50 > [ 55.878654] [] cpufreq_cpu_get+0x75/0xc0 > [ 55.946528] [] cpufreq_update_policy+0x2e/0x1f0 > [ 56.021682] [] ? up+0x32/0x50 > [ 56.078126] [] ? acpi_ns_get_node+0xcb/0xf2 > [ 56.148974] [] ? acpi_evaluate_object+0x22c/0x252 > [ 56.226066] [] ? acpi_get_handle+0x95/0xc0 > [ 56.295871] [] ? acpi_has_method+0x25/0x40 > [ 56.365661] [] acpi_processor_ppc_has_changed+0x77/0x82 > [ 56.448956] [] ? move_linked_works+0x66/0x90 > [ 56.520842] [] acpi_processor_notify+0x58/0xe7 > [ 56.594807] [] acpi_ev_notify_dispatch+0x44/0x5c > [ 56.670859] [] acpi_os_execute_deferred+0x15/0x22 > [ 56.747936] [] process_one_work+0x14e/0x3f0 > [ 56.818766] [] worker_thread+0x11b/0x4d0 > [ 56.886486] [] ? rescuer_thread+0x350/0x350 > [ 56.957316] [] kthread+0xe1/0x100 > [ 57.017742] [] ? kthread_create_on_node+0x1b0/0x1b0 > [ 57.096903] [] ret_from_fork+0x7c/0xb0 > [ 57.162534] [] ? kthread_create_on_node+0x1b0/0x1b0 > [ 57.241680] ---[ end trace dce06bb76f547de5 ]--- > > > Any idea ? No. Santosh reported this to me few days back, I asked him to perform some testing but don't know what happened after that.. Can you give me full kernel logs along with the crash after this patch. You will be required to do some testing this time as I don't have any clue about the problem.. diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index b4375021238f..230a59d2e0d7 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -214,8 +214,10 @@ struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu) if (cpufreq_driver) { /* get the CPU */ policy = per_cpu(cpufreq_cpu_data, cpu); - if (policy) + if (policy) { kobject_get(&policy->kobj); + pr_info("%s: %d", __func__, atomic_read(&policy->kobj.kref.refcount)); + } } read_unlock_irqrestore(&cpufreq_driver_lock, flags); @@ -233,6 +235,7 @@ void cpufreq_cpu_put(struct cpufreq_policy *policy) return; kobject_put(&policy->kobj); + pr_info("%s: %d", __func__, atomic_read(&policy->kobj.kref.refcount)); up_read(&cpufreq_rwsem); } EXPORT_SYMBOL_GPL(cpufreq_cpu_put); -- 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/