On Mon, 3 Dec 2007 15:19:25 +0100 Ingo Molnar <[EMAIL PROTECTED]> wrote:
> this patch extends the soft-lockup detector to automatically > detect hung TASK_UNINTERRUPTIBLE tasks. Such hung tasks are > printed the following way: > > ------------------> > INFO: task prctl:3042 blocked for more than 120 seconds. > "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message > prctl D fd5e3793 0 3042 2997 > f6050f38 00000046 00000001 fd5e3793 00000009 c06d8264 c06dae80 > 00000286 > f6050f40 f6050f00 f7d34d90 f7d34fc8 c1e1be80 00000001 f6050000 > 00000000 > f7e92d00 00000286 f6050f18 c0489d1a f6050f40 00006605 00000000 > c0133a5b > Call Trace: > [<c04883a5>] schedule_timeout+0x6d/0x8b > [<c04883d8>] schedule_timeout_uninterruptible+0x15/0x17 > [<c0133a76>] msleep+0x10/0x16 > [<c0138974>] sys_prctl+0x30/0x1e2 > [<c0104c52>] sysenter_past_esp+0x5f/0xa5 > ======================= > 2 locks held by prctl/3042: > #0: (&sb->s_type->i_mutex_key#5){--..}, at: [<c0197d11>] do_fsync+0x38/0x7a > #1: (jbd_handle){--..}, at: [<c01ca3d2>] journal_start+0xc7/0xe9 > <------------------ > > the current default timeout is 120 seconds. Such messages are printed > up to 10 times per bootup. If the system has crashed already then the > messages are not printed. > > if lockdep is enabled then all held locks are printed as well. > > this feature is a natural extension to the softlockup-detector (kernel > locked up without scheduling) and to the NMI watchdog (kernel locked up > with IRQs disabled). This feature will save one full reporter-developer round-trip during investigation of a significant number of bug reports. It might be more practical if it were to dump the traces for _all_ D-state processes when it fires - basically an auto-triggered sysrq-W. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/