Messages in this thread Patch in this message | | | Date | Sat, 26 Apr 2008 11:29:07 -0700 | From | Andrew Morton <> | Subject | Re: spinlock lockup on CPU#0 |
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On Thu, 24 Apr 2008 01:41:32 +0000 "Justin Mattock" <justinmattock@gmail.com> wrote:
> Hello, I recorded a .mov of a spinlock, but cant seem to send it out, > so I have to manually write it down: > > BUG: spinlock lockup on CPU#0, swapper/0, c17fa6c0 > Pid: 0. swapper Not tainted 2.6.25-03562-g3dc5063 #1 > [<c0219fbb>] _raw_spin_lock+0xd5/0xf9 > [<c0377c6b>] _spin_lock+0x8/0xa > [<c011cdce>] task_rq_lock+0x44/0x6b > [<c011cfb4>] try_to_wake+0x2a/0x1c4 > [<co11d159>] default_wake_function+0xb/0xd > [<co118847>] __wake_up_common+0x2f/0x5a > [<c011bc11>] complete+0x2b/0x3e > [<c02ad79a>] usb_api_blocking_completion+0x13/0x15 > [<c02abadc>] usb_hcd_giveback_urb+0x52/0x82 > [<f88686c7>] ehci_urb_done+0x6f/0x7c [ehci_hcd] > [<f8869614>] qh_completions+0x2d7/0x348 [ehci_hcd] > [<f8869721>] ehci_work+0x9c [ehci_hcd] > [<c0107c35>] ? sched_clock+0xb/0x1c > [<c0119bec>] ? __update_rq_clock+0x94/0x15a > [<f886c827>] ehci_irq+0x138/0x15f [ehci_hcd] > [<c02abd9> ] usb_hcd_irq+0x23/0x51 > [<c0151c43>] handle_IRQ_event+0x2a/0x5a > [<c0152d2c>] handle_fasteoi_irq+0x74/0xb6 > [<c01058c5>] do_IRQ+0x71/0x8c > [<c01042f7>] common_interrupt+0x23/0x28 > [<c011fb07>] ? sched_clock_idle_wakeup_event+0x5b/0x74 > [<c02cc212>] acpi_idle_enter_bm+0x2a4/0x31f [processor] > [<c02cc212>] cpuidle_idle_call+0x5c/0x8c > [<c02cc1b4>] ? cpuidle_idle_call+0x0/0x8c > [<c0102571>] cpu_idle+0xb1/0xd1 > [<c036b371>] reset_init+0x49/0x4b > ===================================================== > > > Hopefully the numbers are right, and hopefully this provides enough > info to help the kernel out
Well that's cute. At a guess I'd say that acpi_processor_idle() managed to call sched_clock_idle_wakeup_event() with local interrupts enabled. We took an interrupt with rq->lock held and things went downhill from there.
Can you add this please, see if it triggers?
--- a/kernel/sched.c~a +++ a/kernel/sched.c @@ -811,6 +811,7 @@ void sched_clock_idle_sleep_event(void) { struct rq *rq = cpu_rq(smp_processor_id()); + WARN_ON(!irqs_disabled()); spin_lock(&rq->lock); __update_rq_clock(rq); spin_unlock(&rq->lock); @@ -826,6 +827,7 @@ void sched_clock_idle_wakeup_event(u64 d struct rq *rq = cpu_rq(smp_processor_id()); u64 now = sched_clock(); + WARN_ON(!irqs_disabled()); rq->idle_clock += delta_ns; /* * Override the previous timestamp and ignore all _
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