> On 11/10, Ingo Molnar wrote: > > > > * Rafael J. Wysocki <rjw@xxxxxxx> wrote: > > > > > This message has been generated automatically as a part of a report > > > of regressions introduced between 2.6.26 and 2.6.27. > > > > > > The following bug entry is on the current list of known regressions > > > introduced between 2.6.26 and 2.6.27. Please verify if it still should > > > be listed and let me know (either way). > > > > > > Bug-Entry : http://bugzilla.kernel.org/show_bug.cgi?id=11380 > > > Subject : lockdep warning: cpu_add_remove_lock at:cpu_maps_update_begin+0x14/0x16 > > > Submitter : Ingo Molnar <mingo@xxxxxxx> > > > Date : 2008-08-20 6:44 (82 days old) > > > References : http://marc.info/?l=linux-kernel&m=121921480931970&w=4 > > > > had a quick look again: i believe this one still triggers, and it's > > caused by some interaction between input code and workqueue code. I > > think it started triggering when Oleg's workqueue annotation patches > > went upstream: > > > > 6af8bf3: workqueues: add comments to __create_workqueue_key() > > 8448502: workqueues: do CPU_UP_CANCELED if CPU_UP_PREPARE fails > > 8de6d30: workqueues: schedule_on_each_cpu() can use schedule_work_on() > > ef1ca23: workqueues: queue_work() can use queue_work_on() > > a67da70: workqueues: lockdep annotations for flush_work() > > 3da1c84: workqueues: make get_online_cpus() useable for work->func() > > 8616a89: workqueues: schedule_on_each_cpu: use flush_work() > > db70089: workqueues: implement flush_work() > > 1a4d9b0: workqueues: insert_work: use "list_head *" instead of "int tail" > > "make get_online_cpus() useable for work->func()" changed the locking. > destroy_workqueue() was changed to take cpu_maps_update_begin() instead > of get_online_cpus(). Other patches can't make any difference afaics. > > Currently I don't understand why lockdep complains, will try to do > more grepping later. I check original report. Is this really cpu hotplug related warnings? it seem simple ABBA lock, right? -> #4 (&dev->mutex){--..}: [<c0160f87>] validate_chain+0x831/0xaa2 [<c0161872>] __lock_acquire+0x67a/0x6e0 [<c0161933>] lock_acquire+0x5b/0x81 [<c0a660e4>] mutex_lock_interruptible_nested+0xde/0x2f8 [<c0782d02>] input_register_handle+0x26/0x7a dev->mutex [<c04a62c9>] kbd_connect+0x64/0x8d [<c0782842>] input_attach_handler+0x38/0x6b [<c0784216>] input_register_handler+0x74/0xc3 input_mutex [<c0f54e4b>] kbd_init+0x66/0x91 [<c0f54f7b>] vty_init+0xce/0xd7 [<c0f54952>] tty_init+0x193/0x197 [<c010112a>] do_one_initcall+0x42/0x133 [<c0f2d5cb>] kernel_init+0x16e/0x1d5 [<c0117c03>] kernel_thread_helper+0x7/0x10 [<ffffffff>] 0xffffffff -> #3 (input_mutex){--..}: [<c0160f87>] validate_chain+0x831/0xaa2 [<c0161872>] __lock_acquire+0x67a/0x6e0 [<c0161933>] lock_acquire+0x5b/0x81 [<c0a660e4>] mutex_lock_interruptible_nested+0xde/0x2f8 [<c0783fbe>] input_register_device+0xff/0x17f input_mutex [<c048a889>] acpi_button_add+0x31e/0x429 [<c04889f4>] acpi_device_probe+0x43/0xde [<c052c67f>] driver_probe_device+0xa5/0x120 [<c052c73c>] __driver_attach+0x42/0x64 dev->sem [<c052be91>] bus_for_each_dev+0x43/0x65 [<c052c507>] driver_attach+0x19/0x1b [<c052c251>] bus_add_driver+0x9e/0x1a1 [<c052c8de>] driver_register+0x76/0xd2 [<c0488dc3>] acpi_bus_register_driver+0x3f/0x41 [<c0f51bf2>] acpi_button_init+0x32/0x51 [<c010112a>] do_one_initcall+0x42/0x133 [<c0f2d201>] do_async_initcalls+0x1a/0x2a [<c0150eec>] run_workqueue+0xc3/0x193 [<c015195d>] worker_thread+0xbb/0xc7 [<c0153e2a>] kthread+0x40/0x66 [<c0117c03>] kernel_thread_helper+0x7/0x10 [<ffffffff>] 0xffffffff -- To unsubscribe from this list: send the line "unsubscribe kernel-testers" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
