Re: i915 X lockup

[Peter Zijlstra <peterz@infradead.org>]

On Fri, 2009-02-27 at 10:28 +0100, Jiri Slaby wrote:

> SysRq : Show Locks Held
> 
> Showing all locks held in the system:
> 3 locks held by events/0/10:
>   #0:  (events){+.+.+.}, at: [<ffffffff8025223d>] worker_thread+0x19d/0x340
>   #1:  (&(&dev_priv->mm.retire_work)->work){+.+...}, at: [<ffffffff8025223d>] worker_thread+0x19d/0x340
>   #2:  (&dev->struct_mutex){+.+.+.}, at: [<ffffffff804057ba>] i915_gem_retire_work_handler+0x3a/0x90

> 1 lock held by X/4007:
>   #0:  (&dev->struct_mutex){+.+.+.}, at: [<ffffffff8040563c>] i915_gem_throttle_ioctl+0x2c/0x60

> =============================================
> 
> INFO: task events/0:10 blocked for more than 120 seconds.
> "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
> events/0      D 0000000000000000     0    10      2
>   ffff8801cb22fd60 0000000000000046 ffff8801cb22fcc0 ffffffff809d5cb0
>   0000000000010400 ffffffff804057ba ffff8801cb20a6d0 ffff8801cb20a080
>   ffff8801cb20a328 00000000802690a3 00000000ffff0ea1 0000000000000002
> Call Trace:
>   [<ffffffff804057ba>] ? i915_gem_retire_work_handler+0x3a/0x90
>   [<ffffffff8026804d>] ? mark_held_locks+0x6d/0x90
>   [<ffffffff80612fb5>] ? mutex_lock_nested+0x185/0x310
>   [<ffffffff80612f46>] mutex_lock_nested+0x116/0x310
>   [<ffffffff804057ba>] ? i915_gem_retire_work_handler+0x3a/0x90
>   [<ffffffff802690a3>] ? __lock_acquire+0xab3/0x12c0
>   [<ffffffff80405780>] ? i915_gem_retire_work_handler+0x0/0x90
>   [<ffffffff804057ba>] i915_gem_retire_work_handler+0x3a/0x90
>   [<ffffffff80252290>] worker_thread+0x1f0/0x340
>   [<ffffffff8025223d>] ? worker_thread+0x19d/0x340
>   [<ffffffff80614aff>] ? _spin_unlock_irqrestore+0x3f/0x60
>   [<ffffffff80256de0>] ? autoremove_wake_function+0x0/0x40
>   [<ffffffff8026838d>] ? trace_hardirqs_on+0xd/0x10
>   [<ffffffff802520a0>] ? worker_thread+0x0/0x340
>   [<ffffffff80256a2e>] kthread+0x9e/0xb0
>   [<ffffffff8020d51a>] child_rip+0xa/0x20
>   [<ffffffff8020cf3c>] ? restore_args+0x0/0x30
>   [<ffffffff80256990>] ? kthread+0x0/0xb0
>   [<ffffffff8020d510>] ? child_rip+0x0/0x20
> 3 locks held by events/0/10:
>   #0:  (events){+.+.+.}, at: [<ffffffff8025223d>] worker_thread+0x19d/0x340
>   #1:  (&(&dev_priv->mm.retire_work)->work){+.+...}, at: [<ffffffff8025223d>] worker_thread+0x19d/0x340
>   #2:  (&dev->struct_mutex){+.+.+.}, at: [<ffffffff804057ba>] i915_gem_retire_work_handler+0x3a/0x90


Looks like eventd blocking on X, would be good to have sysrq-w output
too, to see what X is up to (assuming it is blocked, and not spinning
like mad with a lock held).