Attachment 1482499 Details for Bug 1627950 – WARNING fragement with dependency chain from journal

WARNING fragement with dependency chain from journal

circular.txt (text/plain), 5.86 KB, created by Michal Jaegermann on 2018-09-12 00:02:04 UTC

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Creator: Michal Jaegermann

Created: 2018-09-12 00:02:04 UTC

Size: 5.86 KB

patch

obsolete

> ======================================================
> WARNING: possible circular locking dependency detected
> 4.19.0-0.rc2.git3.1.fc30.x86_64 #1 Not tainted
> ------------------------------------------------------
> kworker/0:3/101 is trying to acquire lock:
> 000000003b2babfd ((work_completion)(&wfc.work)){+.+.}, at: __flush_work+0x28c/0x320
> 
> but task is already holding lock:
> 0000000084d461de (&policy_dbs->update_mutex){+.+.}, at: dbs_work_handler+0x2b/0x70
> 
> which lock already depends on the new lock.
> 
> the existing dependency chain (in reverse order) is:
> 
> -> #5 (&policy_dbs->update_mutex){+.+.}:
>        cpufreq_dbs_governor_limits+0x31/0x80
>        cpufreq_start_governor+0x65/0xa0
>        cpufreq_set_policy+0x2b7/0x330
>        cpufreq_init_policy+0x76/0xe0
>        cpufreq_online+0x535/0x6b0
>        cpufreq_add_dev+0x6b/0x80
>        subsys_interface_register+0xf3/0x150
>        cpufreq_register_driver+0x11e/0x230
>        powernowk8_init+0x134/0x18f [powernow_k8]
>        do_one_initcall+0x5d/0x2be
>        do_init_module+0x5a/0x210
>        load_module+0x2134/0x2400
>        __do_sys_init_module+0x150/0x1a0
>        do_syscall_64+0x60/0x1f0
>        entry_SYSCALL_64_after_hwframe+0x49/0xbe
> 
> -> #4 (gov_dbs_data_mutex){+.+.}:
>        cpufreq_dbs_governor_init+0x117/0x240
>        cpufreq_init_governor+0x62/0xe0
>        cpufreq_set_policy+0x1ca/0x330
>        cpufreq_init_policy+0x76/0xe0
>        cpufreq_online+0x535/0x6b0
>        cpufreq_add_dev+0x6b/0x80
>        subsys_interface_register+0xf3/0x150
>        cpufreq_register_driver+0x11e/0x230
>        powernowk8_init+0x134/0x18f [powernow_k8]
>        do_one_initcall+0x5d/0x2be
>        do_init_module+0x5a/0x210
>        load_module+0x2134/0x2400
>        __do_sys_init_module+0x150/0x1a0
>        do_syscall_64+0x60/0x1f0
>        entry_SYSCALL_64_after_hwframe+0x49/0xbe
> 
> -> #3 (&policy->rwsem){+.+.}:
>        cpufreq_policy_free+0xba/0x140
>        cpufreq_online+0xec/0x6b0
>        cpufreq_add_dev+0x6b/0x80
>        subsys_interface_register+0xf3/0x150
>        cpufreq_register_driver+0x11e/0x230
>        0xffffffffc05fc25a
>        do_one_initcall+0x5d/0x2be
>        do_init_module+0x5a/0x210
>        load_module+0x2134/0x2400
>        __do_sys_init_module+0x150/0x1a0
>        do_syscall_64+0x60/0x1f0
>        entry_SYSCALL_64_after_hwframe+0x49/0xbe
> 
> -> #2 (subsys mutex#7){+.+.}:
>        subsys_interface_register+0x73/0x150
>        cpufreq_register_driver+0x11e/0x230
>        0xffffffffc05fc25a
>        do_one_initcall+0x5d/0x2be
>        do_init_module+0x5a/0x210
>        load_module+0x2134/0x2400
>        __do_sys_init_module+0x150/0x1a0
>        do_syscall_64+0x60/0x1f0
>        entry_SYSCALL_64_after_hwframe+0x49/0xbe
> 
> -> #1 (cpu_hotplug_lock.rw_sem){.+.+}:
>        apply_workqueue_attrs+0x12/0x50
>        __alloc_workqueue_key+0x303/0x480
>        scsi_host_alloc+0x3be/0x450
>        ata_scsi_add_hosts+0xc9/0x150
>        ata_host_register+0x120/0x1d0
>        ata_host_activate+0xc1/0x140
>        svia_init_one+0x6c7/0x7f6 [sata_via]
>        local_pci_probe+0x41/0x90
>        work_for_cpu_fn+0x16/0x20
>        process_one_work+0x27d/0x5c0
>        worker_thread+0x3c/0x390
>        kthread+0x120/0x140
>        ret_from_fork+0x3a/0x50
> 
> -> #0 ((work_completion)(&wfc.work)){+.+.}:
>        __flush_work+0x2ac/0x320
>        work_on_cpu+0x9b/0xd0
>        powernowk8_target+0x33/0x50 [powernow_k8]
>        __cpufreq_driver_target+0x2d2/0x580
>        od_dbs_update+0xbb/0x190
>        dbs_work_handler+0x3a/0x70
>        process_one_work+0x27d/0x5c0
>        worker_thread+0x3c/0x390
>        kthread+0x120/0x140
>        ret_from_fork+0x3a/0x50
> 
> other info that might help us debug this:
> Chain exists of:
>   (work_completion)(&wfc.work) --> gov_dbs_data_mutex --> &policy_dbs->update_mutex
>  Possible unsafe locking scenario:
>        CPU0                    CPU1
>        ----                    ----
>   lock(&policy_dbs->update_mutex);
>                                lock(gov_dbs_data_mutex);
>                                lock(&policy_dbs->update_mutex);
>   lock((work_completion)(&wfc.work));
> 
>  *** DEADLOCK ***
> 3 locks held by kworker/0:3/101:
>  #0: 000000009eaebf60 ((wq_completion)"events"){+.+.}, at: process_one_work+0x1f3/0x5c0
>  #1: 00000000ac2fb241 ((work_completion)(&policy_dbs->work)){+.+.}, at: process_one_work+0x1f3/0x5c0
>  #2: 0000000084d461de (&policy_dbs->update_mutex){+.+.}, at: dbs_work_handler+0x2b/0x70
> 
> stack backtrace:
> CPU: 0 PID: 101 Comm: kworker/0:3 Not tainted 4.19.0-0.rc2.git3.1.fc30.x86_64 #1
> Hardware name: Acer Aspire T135/K8VM800MAE, BIOS R01-A3 06/27/2005
> Workqueue: events dbs_work_handler
> Call Trace:
>  dump_stack+0x85/0xc0
>  print_circular_bug.isra.36.cold.55+0x15c/0x195
>  __lock_acquire+0x139a/0x16c0
>  ? __lock_acquire+0x112b/0x16c0
>  lock_acquire+0x9e/0x180
>  ? __flush_work+0x28c/0x320
>  __flush_work+0x2ac/0x320
>  ? __flush_work+0x28c/0x320
>  ? native_sched_clock+0x3e/0xa0
>  ? mark_held_locks+0x57/0x80
>  ? queue_work_on+0x5d/0x90
>  ? lockdep_hardirqs_on+0xed/0x180
>  work_on_cpu+0x9b/0xd0
>  ? work_is_static_object+0x10/0x10
>  ? write_new_fid+0xe0/0xe0 [powernow_k8]
>  powernowk8_target+0x33/0x50 [powernow_k8]
>  __cpufreq_driver_target+0x2d2/0x580
>  od_dbs_update+0xbb/0x190
>  dbs_work_handler+0x3a/0x70
>  process_one_work+0x27d/0x5c0
>  worker_thread+0x3c/0x390
>  ? process_one_work+0x5c0/0x5c0
>  kthread+0x120/0x140
>  ? kthread_create_worker_on_cpu+0x70/0x70
>  ret_from_fork+0x3a/0x50
> clocksource: timekeeping watchdog on CPU0: Marking clocksource 'tsc' as unstable because the skew is too large:
> clocksource:                       'acpi_pm' wd_now: 61cb7c wd_last: 5e7744 mask: ffffff
> clocksource:                       'tsc' cs_now: 2b9d83ad41 cs_last: 299dc3ef91 mask: ffffffffffffffff
> tsc: Marking TSC unstable due to clocksource watchdog
> TSC found unstable after boot, most likely due to broken BIOS. Use 'tsc=unstable'.
> sched_clock: Marking unstable (55064379271, 12383389)<-(55179340298, -102501740)
> clocksource: Switched to clocksource acpi_pm

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Attachments on bug 1627950: 1482499 | 1515181 | 1526319 | 1646227