2009/9/10 Daniel J Blueman <daniel.blueman@xxxxxxxxx>: > When hot-plugging my SATA DVD drive into my laptop, I see a lockdep > warning [1]. On closer inspection, both flush_workqueue() and > worker_thread() do tricks with lockdep maps. False positive? > Call Trace: > [<ffffffff8108c8a7>] print_circular_bug_tail+0xa7/0x100 > [<ffffffff8108ebe1>] __lock_acquire+0xef1/0x1240 > [<ffffffff8108a808>] ? add_lock_to_list+0x58/0xf0 > [<ffffffff8108f04e>] lock_acquire+0x11e/0x170 > [<ffffffff81073a70>] ? flush_workqueue+0x0/0xf0 (workqueue.c:397) > [<ffffffff812f6ebd>] ? acpi_os_execute_hp_deferred+0x0/0x3e > [<ffffffff81073acc>] flush_workqueue+0x5c/0xf0 (workqueue.c:403) The lockdep warning is caused by calling flush_workqueue() from the work function of acpi_os_execute_hp_deferred. I don't know if it is safe to do that. > [<ffffffff81073a70>] ? flush_workqueue+0x0/0xf0 (workqueue.c:397) > [<ffffffff812f6eaf>] acpi_os_wait_events_complete+0x10/0x1e drivers/acpi/osl.c > [<ffffffff812f6ee7>] acpi_os_execute_hp_deferred+0x2a/0x3e > [<ffffffff81072a98>] worker_thread+0x248/0x3c0 (workqueue.c:292) > [<ffffffff81072a42>] ? worker_thread+0x1f2/0x3c0 > [<ffffffff81077900>] ? autoremove_wake_function+0x0/0x40 > [<ffffffff81072850>] ? worker_thread+0x0/0x3c0 > [<ffffffff81077456>] kthread+0xa6/0xc0 > [<ffffffff8100d29a>] child_rip+0xa/0x20 > [<ffffffff8100cbd4>] ? restore_args+0x0/0x30 > [<ffffffff810773b0>] ? kthread+0x0/0xc0 > [<ffffffff8100d290>] ? child_rip+0x0/0x20 > -- Lei Ming -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
