On Tuesday, 5 June 2007 22:19, Pavel Machek wrote: > Hi! > > > > > [ 116.733327] PM: suspend-to-disk mode set to 'shutdown' [ > > > > 116.738849] swsusp: Basic memory bitmaps created [ 116.745353] > > > > Stopping tasks ... WARNING: at > > > > /home/devel/linux-git/kernel/lockdep.c:2414 check_flags() > > > > > > [ 116.755052] irq event stamp: 69 > > > > [ 116.755060] hardirqs last enabled at (69): [<c04040f9>] syscall_exit_work+0x11/0x26 > > > > [ 116.755084] hardirqs last disabled at (68): [<c0403fdd>] syscall_exit+0x9/0x1a > > > > [ 116.755109] softirqs last enabled at (0): [<c042150c>] copy_process+0x4dd/0x1286 > > > > [ 116.755139] softirqs last disabled at (0): [<00000000>] 0x0 > > > > [ 116.945776] done. > > > > > Well, it's harmless in the sense that "yeah, the system still works", > > > but it does seem to be a real bug. We have hardware interrupts > > > disabled when we _think_ we should have them on, so our irq tracking > > > is off. > > > > > > Ingo, do you see what's up? It looks like we got a signal to a process > > > that just got created, is the setup stuff for "tsk->hardirqs_enabled" > > > perhaps off a bit? > > > > hm. I cannot see the source of the bug at the moment, but here's my > > analysis so far: > > > > the last event that irqtrace got was #69, and that was a 'hardirqs on' > > in syscall_exit_work. After that we did a 'hardirqs off' without > > properly tracking that via irqtrace. Next time we got an irqtrace event > > (event 70) the assert caught up with us and turned off lockdep and > > backed out of that function. This was in: > > > > > [ 116.754957] [<c043c3e5>] check_flags+0x95/0x143 > > > [ 116.754967] [<c043f158>] lock_acquire+0x29/0x82 > > > [ 116.754977] [<c06313a7>] _spin_lock+0x35/0x42 > > > [ 116.754990] [<c044894a>] refrigerator+0x14/0xc6 > > > [ 116.755002] [<c042d4b3>] get_signal_to_deliver+0x33/0x397 > > > [ 116.755016] [<c0403597>] do_notify_resume+0x94/0x6ed > > > [ 116.755029] [<c0404099>] work_notifysig+0x13/0x1a > > > > isnt the refrigerator() suspend related? Perhaps suspend disables irqs > > somewhere that we forgot to track? > > refrigerator is suspend related, but I do not think it does any > interrupt magic. We do magic later in hibernation process. > > This is in kernel/power/process.c, we have spinlock_irqsave there, but > that's pretty much it AFAICT. That's correct. We don't manipulate IRQs directly in the freezer. Greetings, Rafael -- "Premature optimization is the root of all evil." - Donald Knuth _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
