久々に遭遇。再現できるかと思って試したけど再現しなかったので、ログだけ貼っ付けとく。
Jul 26 22:05:33 localhost kernel: [45852.371020] ============================================= Jul 26 22:05:33 localhost kernel: [45852.371026] [ INFO: possible recursive locking detected ] Jul 26 22:05:33 localhost kernel: [45852.371030] 2.6.31-rc3-x86tip-tip #1 Jul 26 22:05:33 localhost kernel: [45852.371033] --------------------------------------------- Jul 26 22:05:33 localhost kernel: [45852.371036] events/0/9 is trying to acquire lock: Jul 26 22:05:33 localhost kernel: [45852.371040] (&tty->output_lock){+.+...}, at: [<ffffffff812800d0>] process_echoes+0x4a/0x2c0 Jul 26 22:05:33 localhost kernel: [45852.371054] Jul 26 22:05:33 localhost kernel: [45852.371055] but task is already holding lock: Jul 26 22:05:33 localhost kernel: [45852.371058] (&tty->output_lock){+.+...}, at: [<ffffffff812800d0>] process_echoes+0x4a/0x2c0 Jul 26 22:05:33 localhost kernel: [45852.371067] Jul 26 22:05:33 localhost kernel: [45852.371067] other info that might help us debug this: Jul 26 22:05:33 localhost kernel: [45852.371071] 4 locks held by events/0/9: Jul 26 22:05:33 localhost kernel: [45852.371073] #0: (events){+.+.+.}, at: [<ffffffff81079866>] worker_thread+0x209/0x396 Jul 26 22:05:33 localhost kernel: [45852.371085] #1: (&(&tty->buf.work)->work){+.+...}, at: [<ffffffff81079866>] worker_thread+0x209/0x396 Jul 26 22:05:33 localhost kernel: [45852.371095] #2: (&tty->output_lock){+.+...}, at: [<ffffffff812800d0>] process_echoes+0x4a/0x2c0 Jul 26 22:05:33 localhost kernel: [45852.371104] #3: (&tty->echo_lock){+.+...}, at: [<ffffffff812800e5>] process_echoes+0x5f/0x2c0 Jul 26 22:05:33 localhost kernel: [45852.371114] Jul 26 22:05:33 localhost kernel: [45852.371115] stack backtrace: Jul 26 22:05:33 localhost kernel: [45852.371119] Pid: 9, comm: events/0 Not tainted 2.6.31-rc3-x86tip-tip #1 Jul 26 22:05:33 localhost kernel: [45852.371122] Call Trace: Jul 26 22:05:33 localhost kernel: [45852.371129] [<ffffffff81095d89>] __lock_acquire+0xbca/0xc6a Jul 26 22:05:33 localhost kernel: [45852.371135] [<ffffffff812800d0>] ? process_echoes+0x4a/0x2c0 Jul 26 22:05:33 localhost kernel: [45852.371141] [<ffffffff812800d0>] ? process_echoes+0x4a/0x2c0 Jul 26 22:05:33 localhost kernel: [45852.371146] [<ffffffff81095f3c>] lock_acquire+0x113/0x153 Jul 26 22:05:33 localhost kernel: [45852.371151] [<ffffffff812800d0>] ? process_echoes+0x4a/0x2c0 Jul 26 22:05:33 localhost kernel: [45852.371156] [<ffffffff81095d4f>] ? __lock_acquire+0xb90/0xc6a Jul 26 22:05:33 localhost kernel: [45852.371163] [<ffffffff8139b9ad>] __mutex_lock_common+0x6e/0x4c7 Jul 26 22:05:33 localhost kernel: [45852.371168] [<ffffffff812800d0>] ? process_echoes+0x4a/0x2c0 Jul 26 22:05:33 localhost kernel: [45852.371173] [<ffffffff81093fff>] ? mark_lock+0x31/0x24c Jul 26 22:05:33 localhost kernel: [45852.371179] [<ffffffff812800d0>] ? process_echoes+0x4a/0x2c0 Jul 26 22:05:33 localhost kernel: [45852.371184] [<ffffffff8109427a>] ? mark_held_locks+0x60/0x95 Jul 26 22:05:33 localhost kernel: [45852.371189] [<ffffffff8139bf15>] mutex_lock_nested+0x48/0x65 Jul 26 22:05:33 localhost kernel: [45852.371194] [<ffffffff812800d0>] process_echoes+0x4a/0x2c0 Jul 26 22:05:33 localhost kernel: [45852.371200] [<ffffffff8128036b>] n_tty_write_wakeup+0x25/0x72 Jul 26 22:05:33 localhost kernel: [45852.371206] [<ffffffff8107ad89>] ? schedule_delayed_work+0x31/0x47 Jul 26 22:05:33 localhost kernel: [45852.371211] [<ffffffff8127e51f>] tty_wakeup+0x49/0x88 Jul 26 22:05:33 localhost kernel: [45852.371217] [<ffffffff81286c63>] pty_write+0x72/0x93 Jul 26 22:05:33 localhost kernel: [45852.371223] [<ffffffff8127bf55>] tty_put_char+0x41/0x57 Jul 26 22:05:33 localhost kernel: [45852.371228] [<ffffffff81280058>] do_output_char+0x20d/0x23b Jul 26 22:05:33 localhost kernel: [45852.371233] [<ffffffff81280291>] process_echoes+0x20b/0x2c0 Jul 26 22:05:33 localhost kernel: [45852.371239] [<ffffffff8128060f>] ? echo_char+0x8b/0xac Jul 26 22:05:33 localhost kernel: [45852.371245] [<ffffffff81281f5d>] n_tty_receive_buf+0x342/0xe67 Jul 26 22:05:33 localhost kernel: [45852.371251] [<ffffffff812856cf>] ? flush_to_ldisc+0x5f/0x1fb Jul 26 22:05:33 localhost kernel: [45852.371256] [<ffffffff8109427a>] ? mark_held_locks+0x60/0x95 Jul 26 22:05:33 localhost kernel: [45852.371262] [<ffffffff8139d4f7>] ? _spin_unlock_irqrestore+0x5e/0xb1 Jul 26 22:05:33 localhost kernel: [45852.371267] [<ffffffff81094584>] ? trace_hardirqs_on_caller+0x123/0x15d Jul 26 22:05:33 localhost kernel: [45852.371272] [<ffffffff810945de>] ? trace_hardirqs_on+0x20/0x36 Jul 26 22:05:33 localhost kernel: [45852.371278] [<ffffffff812857af>] flush_to_ldisc+0x13f/0x1fb Jul 26 22:05:33 localhost kernel: [45852.371284] [<ffffffff810798c0>] worker_thread+0x263/0x396 Jul 26 22:05:33 localhost kernel: [45852.371289] [<ffffffff81079866>] ? worker_thread+0x209/0x396 Jul 26 22:05:33 localhost kernel: [45852.371294] [<ffffffff8107965d>] ? worker_thread+0x0/0x396 Jul 26 22:05:33 localhost kernel: [45852.371299] [<ffffffff81285670>] ? flush_to_ldisc+0x0/0x1fb Jul 26 22:05:33 localhost kernel: [45852.371305] [<ffffffff8139d525>] ? _spin_unlock_irqrestore+0x8c/0xb1 Jul 26 22:05:33 localhost kernel: [45852.371311] [<ffffffff8107fd58>] ? autoremove_wake_function+0x0/0x63 Jul 26 22:05:33 localhost kernel: [45852.371317] [<ffffffff8107965d>] ? worker_thread+0x0/0x396 Jul 26 22:05:33 localhost kernel: [45852.371322] [<ffffffff8107f869>] kthread+0xa8/0xb0 Jul 26 22:05:33 localhost kernel: [45852.371329] [<ffffffff810143da>] child_rip+0xa/0x20 Jul 26 22:05:33 localhost kernel: [45852.371336] [<ffffffff81013d14>] ? restore_args+0x0/0x30 Jul 26 22:05:33 localhost kernel: [45852.371341] [<ffffffff8107f7a0>] ? kthreadd+0x11b/0x13c Jul 26 22:05:33 localhost kernel: [45852.371346] [<ffffffff8107f7c1>] ? kthread+0x0/0xb0 Jul 26 22:05:33 localhost kernel: [45852.371351] [<ffffffff810143d0>] ? child_rip+0x0/0x20 Jul 26 22:08:26 localhost kernel: [46025.306416] mtrr: no MTRR for d0000000,8000000 found Jul 26 22:08:29 localhost kernel: [46028.381110] device eth0 left promiscuous mode Jul 26 22:09:27 localhost kernel: [46086.124033] INFO: task events/0:9 blocked for more than 120 seconds. Jul 26 22:09:27 localhost kernel: [46086.124091] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. Jul 26 22:09:27 localhost kernel: [46086.124145] events/0 D ffff8800b38738c8 0 9 2 0x00000000 Jul 26 22:09:27 localhost kernel: [46086.124238] ffff8800b6fbb920 0000000000000082 0000000000000004 ffffffff81a117b0 Jul 26 22:09:27 localhost kernel: [46086.124386] ffff8800b6fbb890 ffff8800b6fb43c0 00000000001d8580 0000000000010ac0 Jul 26 22:09:27 localhost kernel: [46086.124534] ffff8800b6fb3c60 ffff88009cc9e4a0 ffff8800b6fb3f58 00000000411238be