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| author | Ingo Molnar <mingo@elte.hu> | 2009-11-26 08:29:10 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-11-26 08:29:10 +0100 |
| commit | 67f2de0bf9141dd9fe9189d0caaa28d7ad21a523 (patch) | |
| tree | 6e1693295e6a38efa0a269429d74418f16a76027 /Documentation/ioctl | |
| parent | b803090615ccec669681ff85ce28671e7bfefa3d (diff) | |
x86: dumpstack, 64-bit: Disable preemption when walking the IRQ/exception stacks
This warning:
[ 847.140022] rb_producer D 0000000000000000 5928 519 2 0x00000000
[ 847.203627] BUG: using smp_processor_id() in preemptible [00000000] code: khungtaskd/517
[ 847.207360] caller is show_stack_log_lvl+0x2e/0x241
[ 847.210364] Pid: 517, comm: khungtaskd Not tainted 2.6.32-rc8-tip+ #13761
[ 847.213395] Call Trace:
[ 847.215847] [<ffffffff81413bde>] debug_smp_processor_id+0x1f0/0x20a
[ 847.216809] [<ffffffff81015eae>] show_stack_log_lvl+0x2e/0x241
[ 847.220027] [<ffffffff81018512>] show_stack+0x1c/0x1e
[ 847.223365] [<ffffffff8107b7db>] sched_show_task+0xe4/0xe9
[ 847.226694] [<ffffffff8112f21f>] check_hung_task+0x140/0x199
[ 847.230261] [<ffffffff8112f4a8>] check_hung_uninterruptible_tasks+0x1b7/0x20f
[ 847.233371] [<ffffffff8112f500>] ? watchdog+0x0/0x50
[ 847.236683] [<ffffffff8112f54e>] watchdog+0x4e/0x50
[ 847.240034] [<ffffffff810cee56>] kthread+0x97/0x9f
[ 847.243372] [<ffffffff81012aea>] child_rip+0xa/0x20
[ 847.246690] [<ffffffff81e43494>] ? restore_args+0x0/0x30
[ 847.250019] [<ffffffff81e43083>] ? _spin_lock+0xe/0x10
[ 847.253351] [<ffffffff810cedbf>] ? kthread+0x0/0x9f
[ 847.256833] [<ffffffff81012ae0>] ? child_rip+0x0/0x20
Happens because on preempt-RCU, khungd calls show_stack() with
preemption enabled.
Make sure we are not preemptible while walking the IRQ and exception
stacks on 64-bit. (32-bit stack dumping is preemption safe.)
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'Documentation/ioctl')
0 files changed, 0 insertions, 0 deletions