Re: 2.6.26.4 hard-unsafe lock order detected (drm-related?)

From: Peter Zijlstra
Date: Wed Sep 10 2008 - 14:15:27 EST


On Wed, 2008-09-10 at 17:48 +0100, Marcus Furlong wrote:
> Hi,
>
> Just found this in dmesg, if any more info is needed let me know.

Dave, have you ever seen this one before?

Marcus, can you reproduce? - if so, could you try .27-rc6 to see if it
is still valid?

> [18255.940781] ======================================================
> [18255.940789] [ INFO: hard-safe -> hard-unsafe lock order detected ]
> [18255.940792] 2.6.26.4 #1
> [18255.940794] ------------------------------------------------------
> [18255.940797] swapper/0 [HC0[0]:SC1[2]:HE0:SE0] is trying to acquire:
> [18255.940800] (&dev->lock.spinlock){-+..}, at: [<f9072ecc>]
> drm_lock_take+0x1c/0xc0 [drm]
> [18255.940815]
> [18255.940816] and this task is already holding:
> [18255.940818] (&dev->tasklet_lock){++..}, at: [<f907254e>]
> drm_locked_tasklet_func+0x1e/0x90 [drm]
> [18255.940831] which would create a new lock dependency:
> [18255.940833] (&dev->tasklet_lock){++..} -> (&dev->lock.spinlock){-+..}
> [18255.940840]
> [18255.940841] but this new dependency connects a hard-irq-safe lock:
> [18255.940843] (&dev->tasklet_lock){++..}
> [18255.940846] ... which became hard-irq-safe at:
> [18255.940848] [<c016495d>] __lock_acquire+0x82d/0xfb0
> [18255.940856] [<c0165141>] lock_acquire+0x61/0x80
> [18255.940862] [<c0496de3>] _spin_lock_irqsave+0x43/0x60
> [18255.940869] [<f907260d>] drm_locked_tasklet+0x4d/0xa0 [drm]
> [18255.940880] [<f9048bf3>] i915_driver_irq_handler+0x1c3/0x1f0 [i915]
> [18255.940888] [<c016f048>] handle_IRQ_event+0x28/0x60
> [18255.940892] [<c01704f8>] handle_fasteoi_irq+0x78/0xf0
> [18255.940892] [<c011d719>] do_IRQ+0x79/0xc0
> [18255.940892] [<ffffffff>] 0xffffffff
> [18255.940892]
> [18255.940892] to a hard-irq-unsafe lock:
> [18255.940892] (&dev->lock.spinlock){-+..}
> [18255.940892] ... which became hard-irq-unsafe at:
> [18255.940892] ... [<c0164736>] __lock_acquire+0x606/0xfb0
> [18255.940892] [<c0165141>] lock_acquire+0x61/0x80
> [18255.940892] [<c0496e8b>] _spin_lock_bh+0x3b/0x50
> [18255.940892] [<f907319e>] drm_lock+0x8e/0x310 [drm]
> [18255.940892] [<f90713e9>] drm_ioctl+0x1b9/0x2f0 [drm]
> [18255.940892] [<c01a30eb>] vfs_ioctl+0x6b/0x80
> [18255.940892] [<c01a3157>] do_vfs_ioctl+0x57/0x2b0
> [18255.940892] [<c01a33e9>] sys_ioctl+0x39/0x60
> [18255.940892] [<c011a505>] sysenter_past_esp+0x6a/0xb1
> [18255.940892] [<ffffffff>] 0xffffffff
> [18255.940892]
> [18255.940892] other info that might help us debug this:
> [18255.940892]
> [18255.940892] 1 lock held by swapper/0:
> [18255.940892] #0: (&dev->tasklet_lock){++..}, at: [<f907254e>]
> drm_locked_tasklet_func+0x1e/0x90 [drm]
> [18255.940892]
> [18255.940892] the hard-irq-safe lock's dependencies:
> [18255.940892] -> (&dev->tasklet_lock){++..} ops: 0 {
> [18255.940892] initial-use at:
> [18255.940892] [<c016424d>]
> __lock_acquire+0x11d/0xfb0
> [18255.940892] [<c0165141>]
> lock_acquire+0x61/0x80
> [18255.940892] [<c0496de3>]
> _spin_lock_irqsave+0x43/0x60
> [18255.940892] [<f907260d>]
> drm_locked_tasklet+0x4d/0xa0 [drm]
> [18255.940892] [<f9048bf3>]
> i915_driver_irq_handler+0x1c3/0x1f0 [i915]
> [18255.940892] [<c016f048>]
> handle_IRQ_event+0x28/0x60
> [18255.940892] [<c01704f8>]
> handle_fasteoi_irq+0x78/0xf0
> [18255.940892] [<c011d719>]
> do_IRQ+0x79/0xc0
> [18255.940892] [<ffffffff>] 0xffffffff
> [18255.940892] in-hardirq-W at:
> [18255.940892] [<c016495d>]
> __lock_acquire+0x82d/0xfb0
> [18255.940892] [<c0165141>]
> lock_acquire+0x61/0x80
> [18255.940892] [<c0496de3>]
> _spin_lock_irqsave+0x43/0x60
> [18255.940892] [<f907260d>]
> drm_locked_tasklet+0x4d/0xa0 [drm]
> [18255.940892] [<f9048bf3>]
> i915_driver_irq_handler+0x1c3/0x1f0 [i915]
> [18255.940892] [<c016f048>]
> handle_IRQ_event+0x28/0x60
> [18255.940892] [<c01704f8>]
> handle_fasteoi_irq+0x78/0xf0
> [18255.940892] [<c011d719>]
> do_IRQ+0x79/0xc0
> [18255.940892] [<ffffffff>] 0xffffffff
> [18255.940892] in-softirq-W at:
> [18255.940892] [<c01645ef>]
> __lock_acquire+0x4bf/0xfb0
> [18255.940892] [<c0165141>]
> lock_acquire+0x61/0x80
> [18255.940892] [<c0496de3>]
> _spin_lock_irqsave+0x43/0x60
> [18255.940892] [<f907254e>]
> drm_locked_tasklet_func+0x1e/0x90 [drm]
> [18255.940892] [<c01476eb>]
> tasklet_hi_action+0x5b/0xd0
> [18255.940892] [<c01474e4>]
> __do_softirq+0x74/0xe0
> [18255.940892] [<c011d665>]
> do_softirq+0x95/0xd0
> [18255.940892] [<ffffffff>] 0xffffffff
> [18255.940892] }
> [18255.940892] ... key at: [<f907e444>] __key.23164+0x0/0xffff90cb [drm]
> [18255.940892]
> [18255.940892] the hard-irq-unsafe lock's dependencies:
> [18255.940892] -> (&dev->lock.spinlock){-+..} ops: 0 {
> [18255.940892] initial-use at:
> [18255.940892] [<c016424d>]
> __lock_acquire+0x11d/0xfb0
> [18255.940892] [<c0165141>]
> lock_acquire+0x61/0x80
> [18255.940892] [<c0496e8b>]
> _spin_lock_bh+0x3b/0x50
> [18255.940892] [<f907319e>]
> drm_lock+0x8e/0x310 [drm]
> [18255.940892] [<f90713e9>]
> drm_ioctl+0x1b9/0x2f0 [drm]
> [18255.940892] [<c01a30eb>]
> vfs_ioctl+0x6b/0x80
> [18255.940892] [<c01a3157>]
> do_vfs_ioctl+0x57/0x2b0
> [18255.940892] [<c01a33e9>]
> sys_ioctl+0x39/0x60
> [18255.940892] [<c011a505>]
> sysenter_past_esp+0x6a/0xb1
> [18255.940892] [<ffffffff>] 0xffffffff
> [18255.940892] in-softirq-W at:
> [18255.940892] [<c01645ef>]
> __lock_acquire+0x4bf/0xfb0
> [18255.940892] [<c0165141>]
> lock_acquire+0x61/0x80
> [18255.940892] [<c0496e8b>]
> _spin_lock_bh+0x3b/0x50
> [18255.940892] [<f9072ecc>]
> drm_lock_take+0x1c/0xc0 [drm]
> [18255.940892] [<f907256a>]
> drm_locked_tasklet_func+0x3a/0x90 [drm]
> [18255.940892] [<c01476eb>]
> tasklet_hi_action+0x5b/0xd0
> [18255.940892] [<c01474e4>]
> __do_softirq+0x74/0xe0
> [18255.940892] [<c011d665>]
> do_softirq+0x95/0xd0
> [18255.940892] [<ffffffff>] 0xffffffff
> [18255.940892] hardirq-on-W at:
> [18255.940892] [<c0164736>]
> __lock_acquire+0x606/0xfb0
> [18255.940892] [<c0165141>]
> lock_acquire+0x61/0x80
> [18255.940892] [<c0496e8b>]
> _spin_lock_bh+0x3b/0x50
> [18255.940892] [<f907319e>]
> drm_lock+0x8e/0x310 [drm]
> [18255.940892] [<f90713e9>]
> drm_ioctl+0x1b9/0x2f0 [drm]
> [18255.940892] [<c01a30eb>]
> vfs_ioctl+0x6b/0x80
> [18255.940892] [<c01a3157>]
> do_vfs_ioctl+0x57/0x2b0
> [18255.940892] [<c01a33e9>]
> sys_ioctl+0x39/0x60
> [18255.940892] [<c011a505>]
> sysenter_past_esp+0x6a/0xb1
> [18255.940892] [<ffffffff>] 0xffffffff
> [18255.940892] }
> [18255.940892] ... key at: [<f907e43c>] __key.23165+0x0/0xffff90d3 [drm]
> [18255.940892]
> [18255.940892] stack backtrace:
> [18255.940892] Pid: 0, comm: swapper Not tainted 2.6.26.4 #1
> [18255.940892] [<c0164072>] check_usage+0x252/0x260
> [18255.940892] [<c0164c18>] __lock_acquire+0xae8/0xfb0
> [18255.940892] [<c0165141>] lock_acquire+0x61/0x80
> [18255.940892] [<f9072ecc>] ? drm_lock_take+0x1c/0xc0 [drm]
> [18255.940892] [<c0496e8b>] _spin_lock_bh+0x3b/0x50
> [18255.940892] [<f9072ecc>] ? drm_lock_take+0x1c/0xc0 [drm]
> [18255.940892] [<f9072ecc>] drm_lock_take+0x1c/0xc0 [drm]
> [18255.940892] [<f907256a>] drm_locked_tasklet_func+0x3a/0x90 [drm]
> [18255.940892] [<c01476eb>] tasklet_hi_action+0x5b/0xd0
> [18255.940892] [<c01474e4>] __do_softirq+0x74/0xe0
> [18255.940892] [<c011d665>] do_softirq+0x95/0xd0
> [18255.940892] [<c0170480>] ? handle_fasteoi_irq+0x0/0xf0
> [18255.940892] [<c0147386>] irq_exit+0x86/0xa0
> [18255.940892] [<c011d720>] do_IRQ+0x80/0xc0
> [18255.940892] [<c011af82>] common_interrupt+0x2e/0x34
> [18255.940892] [<c01600d8>] ? tick_setup_oneshot+0x28/0x40
> [18255.940892] [<c030fa9f>] ? acpi_idle_enter_bm+0x297/0x306
> [18255.940892] [<c03cfd0b>] cpuidle_idle_call+0x6b/0xc0
> [18255.940892] [<c03cfca0>] ? cpuidle_idle_call+0x0/0xc0
> [18255.940892] [<c0118f70>] cpu_idle+0x60/0xf0
> [18255.940892] [<c04806f2>] rest_init+0x62/0x70
> [18255.940892] =======================
>
>
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