Dear Paul and others,

On vanilla kernel 3.1.3, I got the following during boot.

BUG: scheduling while atomic: swapper/0/0x10000002
no locks held by swapper/0.
Modules linked in:
Pid: 0, comm: swapper Not tainted 3.1.3.debug+ #32
Call Trace:
[<ffffffff814058de>] __schedule_bug+0x60/0x65
[<ffffffff8189b85a>] ? pidmap_init+0x84/0xc4
[<ffffffff8140a3d9>] __schedule+0x759/0x920
[<ffffffff8189b85a>] ? pidmap_init+0x84/0xc4
[<ffffffff8103d855>] __cond_resched+0x25/0x40
[<ffffffff8140a61d>] _cond_resched+0x2d/0x40
[<ffffffff811107df>] kmem_cache_alloc_trace+0x4f/0x1d0
[<ffffffff8189b85a>] pidmap_init+0x84/0xc4
[<ffffffff8188ab47>] start_kernel+0x339/0x3bc
[<ffffffff8188a322>] x86_64_start_reservations+0x132/0x136
[<ffffffff8188a416>] x86_64_start_kernel+0xf0/0xf7

A little googling revealed that patch [2] "rcu: Avoid having 
just-onlined CPU resched itself when RCU is idle"
is supposed to address this issue. However, booting 3.1.3 with patch [2] 
leads to three new "BUG: scheduling while atomic: swapper/0/0x10000002" 
reports every boot.

The exact blurb varies a little bit, but all backtraces seem ACPI 
related. I include three examples below. Some old [4] and new [1,3] 
similar threads exist, but without resolution as far as I can tell.

The machine, a 2008 macbook 4.1, seems to be fine.

Is this just noise (produced by overzealous debugging checks) that I 
should safely ignore? If not, please let me know what I can do to help 
track this down.

With kind regards,

Wouter Koolen




[1] http://www.spinics.net/lists/kernel/msg1245138.html
[2] https://lkml.org/lkml/2011/8/19/355
[3] https://lkml.org/lkml/2011/9/12/215
[4] https://lkml.org/lkml/2009/9/21/36





BUG: scheduling while atomic: swapper/0/0x10000002
no locks held by swapper/0.
Modules linked in:
Pid: 0, comm: swapper Not tainted 3.1.3.debug+ #36
Call Trace:
  [<ffffffff8140d69e>] __schedule_bug+0x60/0x65
  [<ffffffff8122ba71>] ? acpi_ns_create_node+0x31/0x41
  [<ffffffff81412199>] __schedule+0x759/0x920
  [<ffffffff81086e20>] ? __module_address+0xa0/0xa0
  [<ffffffff8122ba71>] ? acpi_ns_create_node+0x31/0x41
  [<ffffffff8103d855>] __cond_resched+0x25/0x40
  [<ffffffff814123dd>] _cond_resched+0x2d/0x40
  [<ffffffff811103ab>] kmem_cache_alloc+0x4b/0x1f0
  [<ffffffff8122ba71>] acpi_ns_create_node+0x31/0x41
  [<ffffffff8122b267>] acpi_ns_search_and_enter+0x264/0x2a1
  [<ffffffff81118ec2>] ? create_object+0x1f2/0x2d0
  [<ffffffff811cd3cb>] ? prio_tree_insert+0x12b/0x2a0
  [<ffffffff8122a913>] acpi_ns_lookup+0x42b/0x5ad
  [<ffffffff81118ec2>] ? create_object+0x1f2/0x2d0
  [<ffffffff8121b87c>] acpi_ds_load1_begin_op+0x2b7/0x370
  [<ffffffff81230fc2>] acpi_ps_parse_loop+0x321/0xa4f
  [<ffffffff81238118>] ? acpi_ut_create_generic_state+0x2d/0x4a
  [<ffffffff8123075a>] acpi_ps_parse_aml+0x107/0x37d
  [<ffffffff8122e7b9>] acpi_ns_one_complete_parse+0x125/0x142
  [<ffffffff8120ed80>] ? acpi_os_signal_semaphore+0x5f/0x6f
  [<ffffffff8122e81f>] acpi_ns_parse_table+0x49/0x8e
  [<ffffffff8122addd>] acpi_ns_load_table+0x75/0x110
  [<ffffffff81233788>] acpi_load_tables+0xa1/0x18e
  [<ffffffff818a9959>] acpi_early_init+0x6c/0xf7
  [<ffffffff8188abb8>] start_kernel+0x3aa/0x3bc
  [<ffffffff8188a322>] x86_64_start_reservations+0x132/0x136
  [<ffffffff8188a416>] x86_64_start_kernel+0xf0/0xf7



BUG: scheduling while atomic: swapper/0/0x10000002
no locks held by swapper/0.
Modules linked in:
Pid: 0, comm: swapper Not tainted 3.1.3.debug+ #36
Call Trace:
  [<ffffffff8140d69e>] __schedule_bug+0x60/0x65
  [<ffffffff81231ab6>] ? acpi_os_acquire_object+0x26/0x28
  [<ffffffff81412199>] __schedule+0x759/0x920
  [<ffffffff81238118>] ? acpi_ut_create_generic_state+0x2d/0x4a
  [<ffffffff81239435>] ? acpi_ut_get_node_name+0x42/0x49
  [<ffffffff81231ab6>] ? acpi_os_acquire_object+0x26/0x28
  [<ffffffff8103d855>] __cond_resched+0x25/0x40
  [<ffffffff814123dd>] _cond_resched+0x2d/0x40
  [<ffffffff811103ab>] kmem_cache_alloc+0x4b/0x1f0
  [<ffffffff81118ec2>] ? create_object+0x1f2/0x2d0
  [<ffffffff81231ab6>] acpi_os_acquire_object+0x26/0x28
  [<ffffffff81231afd>] acpi_ps_alloc_op+0x37/0x5d
  [<ffffffff8121b8ea>] acpi_ds_load1_begin_op+0x325/0x370
  [<ffffffff81230161>] ? acpi_ps_get_next_arg+0x67/0x2b6
  [<ffffffff81230fc2>] acpi_ps_parse_loop+0x321/0xa4f
  [<ffffffff81238118>] ? acpi_ut_create_generic_state+0x2d/0x4a
  [<ffffffff8123075a>] acpi_ps_parse_aml+0x107/0x37d
  [<ffffffff8122e7b9>] acpi_ns_one_complete_parse+0x125/0x142
  [<ffffffff8120ed80>] ? acpi_os_signal_semaphore+0x5f/0x6f
  [<ffffffff8122e81f>] acpi_ns_parse_table+0x49/0x8e
  [<ffffffff8122addd>] acpi_ns_load_table+0x75/0x110
  [<ffffffff81233788>] acpi_load_tables+0xa1/0x18e
  [<ffffffff818a9959>] acpi_early_init+0x6c/0xf7
  [<ffffffff8188abb8>] start_kernel+0x3aa/0x3bc
  [<ffffffff8188a322>] x86_64_start_reservations+0x132/0x136
  [<ffffffff8188a416>] x86_64_start_kernel+0xf0/0xf7

BUG: scheduling while atomic: swapper/0/0x10000002
no locks held by swapper/0.
Modules linked in:
Pid: 0, comm: swapper Not tainted 3.1.3.debug+ #36
Call Trace:
  [<ffffffff8140d69e>] __schedule_bug+0x60/0x65
  [<ffffffff81412199>] __schedule+0x759/0x920
  [<ffffffff8103d855>] __cond_resched+0x25/0x40
  [<ffffffff814123dd>] _cond_resched+0x2d/0x40
  [<ffffffff81230c8c>] acpi_ps_complete_op+0x2bc/0x2d1
  [<ffffffff8120ee16>] ? acpi_os_release_object+0x9/0xd
  [<ffffffff81231559>] acpi_ps_parse_loop+0x8b8/0xa4f
  [<ffffffff81238118>] ? acpi_ut_create_generic_state+0x2d/0x4a
  [<ffffffff8123075a>] acpi_ps_parse_aml+0x107/0x37d
  [<ffffffff8122e7b9>] acpi_ns_one_complete_parse+0x125/0x142
  [<ffffffff8120ed80>] ? acpi_os_signal_semaphore+0x5f/0x6f
  [<ffffffff8122e85d>] acpi_ns_parse_table+0x87/0x8e
  [<ffffffff8122addd>] acpi_ns_load_table+0x75/0x110
  [<ffffffff81233788>] acpi_load_tables+0xa1/0x18e
  [<ffffffff818a9959>] acpi_early_init+0x6c/0xf7
  [<ffffffff8188abb8>] start_kernel+0x3aa/0x3bc
  [<ffffffff8188a322>] x86_64_start_reservations+0x132/0x136
  [<ffffffff8188a416>] x86_64_start_kernel+0xf0/0xf7