On Sun, Nov 20, 2011 at 6:36 PM, Clark Williams
<clark.williams@xxxxxxxxx> wrote:
> Thomas/Peter,
>
> I have the following lockdep splat running 3.2-rc2-rt3+:
>
> [ 8807.696833] BUG: MAX_LOCKDEP_ENTRIES too low!
> [ 8807.696835] turning off the locking correctness validator.
> [ 8807.696839] Pid: 1347, comm: Xorg Tainted: G W 3.2.0-rc2-rt3+ #4
> [ 8807.696841] Call Trace:
> [ 8807.696847] [<ffffffff81086d79>] add_lock_to_list.constprop.21+0x45/0xa7
> [ 8807.696854] [<ffffffff81088844>] check_prev_add+0x187/0x207
> [ 8807.696859] [<ffffffff8101576e>] ? native_sched_clock+0x34/0x36
> [ 8807.696862] [<ffffffff810154f1>] ? __cycles_2_ns+0xe/0x3a
> [ 8807.696865] [<ffffffff8108894f>] check_prevs_add+0x8b/0x104
> [ 8807.696869] [<ffffffff81088d29>] validate_chain+0x361/0x39d
> [ 8807.696872] [<ffffffff81089404>] __lock_acquire+0x37a/0x3f3
> [ 8807.696877] [<ffffffff810b802e>] ? rcu_preempt_note_context_switch+0x16d/0x184
> [ 8807.696883] [<ffffffff814dbdf2>] ? __schedule+0xca/0x505
> [ 8807.696886] [<ffffffff81089960>] lock_acquire+0xc4/0x108
> [ 8807.696889] [<ffffffff814dbdf2>] ? __schedule+0xca/0x505
> [ 8807.696893] [<ffffffff810b802e>] ? rcu_preempt_note_context_switch+0x16d/0x184
> [ 8807.696897] [<ffffffff814de23a>] _raw_spin_lock_irq+0x4a/0x7e
> [ 8807.696900] [<ffffffff814dbdf2>] ? __schedule+0xca/0x505
> [ 8807.696903] [<ffffffff810b8d16>] ? rcu_note_context_switch+0x34/0x39
> [ 8807.696906] [<ffffffff814dbdf2>] __schedule+0xca/0x505
> [ 8807.696909] [<ffffffff814dc285>] ? preempt_schedule_irq+0x36/0x5f
> [ 8807.696912] [<ffffffff81140876>] ? dentry_iput+0x49/0xaf
> [ 8807.696914] [<ffffffff814dc28f>] preempt_schedule_irq+0x40/0x5f
> [ 8807.696916] [<ffffffff814de926>] retint_kernel+0x26/0x30
> [ 8807.696919] [<ffffffff8111ea8e>] ? __local_lock_irq+0x26/0x79
> [ 8807.696921] [<ffffffff8111ea8e>] ? __local_lock_irq+0x26/0x79
> [ 8807.696925] [<ffffffff810857ef>] ? arch_local_irq_restore+0x6/0xd
> [ 8807.696927] [<ffffffff8108987a>] lock_release+0x89/0xab
> [ 8807.696929] [<ffffffff814ddabb>] rt_spin_unlock+0x20/0x2c
> [ 8807.696931] [<ffffffff81140876>] dentry_iput+0x49/0xaf
> [ 8807.696933] [<ffffffff81141392>] dentry_kill+0xcd/0xe4
> [ 8807.696935] [<ffffffff811417b9>] dput+0xf1/0x102
> [ 8807.696938] [<ffffffff81130922>] __fput+0x1a9/0x1c1
> [ 8807.696951] [<ffffffffa002b3da>] ? drm_gem_handle_create+0xe1/0xe1 [drm]
> [ 8807.696953] [<ffffffff81130957>] fput+0x1d/0x1f
> [ 8807.696959] [<ffffffffa002b17e>] drm_gem_object_release+0x17/0x19 [drm]
> [ 8807.696973] [<ffffffffa009a13d>] nouveau_gem_object_del+0x55/0x64 [nouveau]
> [ 8807.696980] [<ffffffffa002b408>] drm_gem_object_free+0x2e/0x30 [drm]
> [ 8807.696983] [<ffffffff8125acd7>] kref_put+0x43/0x4d
> [ 8807.696989] [<ffffffffa002b0d8>] drm_gem_object_unreference_unlocked+0x36/0x43 [drm]
> [ 8807.696996] [<ffffffffa002b1f0>] drm_gem_object_handle_unreference_unlocked.part.0+0x27/0x2c [drm]
> [ 8807.697002] [<ffffffffa002b2e8>] drm_gem_handle_delete+0xac/0xbd [drm]
> [ 8807.697010] [<ffffffffa002b7d9>] drm_gem_close_ioctl+0x28/0x2a [drm]
> [ 8807.697016] [<ffffffffa0029a2c>] drm_ioctl+0x2ce/0x3ae [drm]
> [ 8807.697018] [<ffffffff8112eb28>] ? do_sync_read+0xc2/0x102
> [ 8807.697021] [<ffffffff8104aa12>] ? finish_task_switch+0x3f/0xf8
> [ 8807.697027] [<ffffffffa002b7b1>] ? drm_gem_destroy+0x43/0x43 [drm]
> [ 8807.697031] [<ffffffff8113e165>] do_vfs_ioctl+0x27e/0x296
> [ 8807.697033] [<ffffffff81089dff>] ? trace_hardirqs_on_caller.part.20+0xbd/0xf4
> [ 8807.697035] [<ffffffff811305c7>] ? fget_light+0x3a/0xa4
> [ 8807.697038] [<ffffffff8113e1d3>] sys_ioctl+0x56/0x7b
> [ 8807.697040] [<ffffffff8111ea8e>] ? __local_lock_irq+0x26/0x79
> [ 8807.697043] [<ffffffff814e46c2>] system_call_fastpath+0x16/0x1b
>
>
> $ sudo cat /proc/lockdep_stats
> lock-classes: 1667 [max: 8191]
> direct dependencies: 16384 [max: 16384]
> indirect dependencies: 64565
> all direct dependencies: 76304
> dependency chains: 29400 [max: 32768]
> dependency chain hlocks: 125503 [max: 163840]
> in-hardirq chains: 22
> in-softirq chains: 0
> in-process chains: 29378
> stack-trace entries: 236171 [max: 262144]
> combined max dependencies: 675717
> hardirq-safe locks: 20
> hardirq-unsafe locks: 1498
> softirq-safe locks: 0
> softirq-unsafe locks: 1498
> irq-safe locks: 20
> irq-unsafe locks: 1498
> hardirq-read-safe locks: 0
> hardirq-read-unsafe locks: 217
> softirq-read-safe locks: 0
> softirq-read-unsafe locks: 217
> irq-read-safe locks: 0
> irq-read-unsafe locks: 217
> uncategorized locks: 44
> unused locks: 0
> max locking depth: 18
> max bfs queue depth: 1016
> debug_locks: 0
>
>
> I've saved /proc/{lockdep, lock_stat, lockdep-chains} if you want to
> see them.
>
> System is a Lenovo Thinkpad W510, quadcore i7 (HT enabled), with 4GB of
> RAM.
>
Me too, I've had this problem with quite a few kernels for awhile,
although I probably enable more debug options than Clark does. This is
a real PITA - because I really like lockdep functionality, and don't
feel like I should have to give up other debug functionality to have
it. If there is nothing obviously wrong I think we ought to consider a
patch to raise the MAX_LOCKDEP_ENTRIES, at least optionally at config
time.
John
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