On Thu, Oct 10, 2013 at 05:12:19PM +0200, Ingo Molnar wrote:
>
> * Jakub Jelinek <ja...@redhat.com> wrote:
>
> > On Thu, Oct 10, 2013 at 07:04:18AM -0700, Richard Henderson wrote:
> > > On 10/10/2013 01:31 AM, Jakub Jelinek wrote:
> > > > Also, for the bitops patch, you probably want an asm_volatile_goto
> > > > variant.
> > >
> > > Why? Asm without output (which asm goto must be) are automatically
> > > volatile.
> >
> > You're right.
>
> Indeed. Something like the updated version below?
>
> [ I kept the asm_volatile_goto() naming to make sure the implicit volatile
> is visible. ]
Ingo, I applied this patch (as commit c015a7f0b746) on top of
tip/sched/core
3354781a2184 "sched/numa: Reflow task_numa_group() to avoid a compiler
warning"
The below results show that it does fixed the many oops:
/kernel/i386-randconfig-i005-1008/c015a7f0b746d0a7e18b82876bd2b693722479d2
+--------------------------------------------------------------+--------------+--------------+
| | 3354781a2184 |
c015a7f0b746 |
+--------------------------------------------------------------+--------------+--------------+
| WARNING:CPU:PID:at_fs/sysfs/dir.c:sysfs_add_one() | 9 |
|
| WARNING:CPU:PID:at_lib/kobject.c:kobject_add_internal() | 9 |
|
| WARNING:CPU:PID:at_drivers/base/driver.c:driver_unregister() | 9 |
|
| WARNING:CPU:PID:at_lib/list_debug.c:__list_add() | 9 |
|
| kernel_BUG_at_kernel/timer.c | 9 |
|
| invalid_opcode:PREEMPT_SMP | 9 |
|
| Kernel_panic-not_syncing:Fatal_exception_in_interrupt | 9 |
|
| good_boots | 0 |
9 |
+--------------------------------------------------------------+--------------+--------------+
/kernel/i386-randconfig-r4-1009/c015a7f0b746d0a7e18b82876bd2b693722479d2
+--------------------------------------------------------------+--------------+--------------+
| | 3354781a2184 |
c015a7f0b746 |
+--------------------------------------------------------------+--------------+--------------+
| BUG:kernel_early_hang_without_any_printk_output | 2 |
3 |
| WARNING:CPU:PID:at_fs/sysfs/dir.c:sysfs_add_one() | 7 |
|
| WARNING:CPU:PID:at_lib/kobject.c:kobject_add_internal() | 7 |
|
| WARNING:CPU:PID:at_drivers/base/driver.c:driver_unregister() | 7 |
|
| WARNING:CPU:PID:at_lib/debugobjects.c:debug_print_object() | 7 |
|
| INFO:trying_to_register_non-static_key | 7 |
|
| kernel_BUG_at_kernel/timer.c | 7 |
|
| invalid_opcode:SMP | 7 |
|
| Kernel_panic-not_syncing:Fatal_exception_in_interrupt | 7 |
|
| good_boots | 0 |
6 |
+--------------------------------------------------------------+--------------+--------------+
/kernel/i386-randconfig-r8-1005/c015a7f0b746d0a7e18b82876bd2b693722479d2
+---------------------------------------------------------------+--------------+--------------+
| | 3354781a2184
| c015a7f0b746 |
+---------------------------------------------------------------+--------------+--------------+
| BUG:unable_to_handle_kernel_NULL_pointer_dereference_at | 1
| |
| Oops:DEBUG_PAGEALLOC | 9
| |
| kernel_BUG_at_kernel/cred.c | 1
| |
| invalid_opcode:DEBUG_PAGEALLOC | 1
| |
| Kernel_panic-not_syncing:CRED:put_cred_rcu()sees_with_usage | 4
| |
| BUG:unable_to_handle_kernel_paging_request_at | 3
| |
| BUG:unable_to_handle_kernel_NULL_pointer_dereference_at(null) | 5
| |
| good_boots | 0
| 9 |
+---------------------------------------------------------------+--------------+--------------+
However it seems that it leads to or increases the chances of early
boot hang:
/kernel/x86_64-randconfig-a1-1009/c015a7f0b746d0a7e18b82876bd2b693722479d2
+-------------------------------------------------+--------------+--------------+
| | 3354781a2184 | c015a7f0b746
|
+-------------------------------------------------+--------------+--------------+
| good_boots | 9 | 8
|
| BUG:kernel_early_hang_without_any_printk_output | 0 | 1
|
+-------------------------------------------------+--------------+--------------+
/kernel/x86_64-randconfig-a5-1009/c015a7f0b746d0a7e18b82876bd2b693722479d2
+-------------------------------------------------+--------------+--------------+
| | 3354781a2184 | c015a7f0b746
|
+-------------------------------------------------+--------------+--------------+
| good_boots | 9 | 8
|
| BUG:kernel_early_hang_without_any_printk_output | 0 | 1
|
+-------------------------------------------------+--------------+--------------+
/kernel/i386-randconfig-r1-1009/c015a7f0b746d0a7e18b82876bd2b693722479d2
+-------------------------------------------------+--------------+--------------+
| | 3354781a2184 | c015a7f0b746
|
+-------------------------------------------------+--------------+--------------+
| BUG:kernel_early_hang_without_any_printk_output | 9 | 9
|
+-------------------------------------------------+--------------+--------------+
/kernel/i386-randconfig-r7-1009/c015a7f0b746d0a7e18b82876bd2b693722479d2
+--------------------------------------------------+--------------+--------------+
| | 3354781a2184 |
c015a7f0b746 |
+--------------------------------------------------+--------------+--------------+
| BUG:soft_lockup-CPU_stuck_for_s | 1 |
|
| INFO:task_blocked_for_more_than_seconds | 8 | 8
|
| Kernel_panic-not_syncing:hung_task:blocked_tasks | 8 | 8
|
| BUG:kernel_early_hang_without_any_printk_output | 0 | 1
|
+--------------------------------------------------+--------------+--------------+
/kernel/i386-randconfig-r5-1009/c015a7f0b746d0a7e18b82876bd2b693722479d2
+-------------------------------------------------+--------------+--------------+
| | 3354781a2184 | c015a7f0b746
|
+-------------------------------------------------+--------------+--------------+
| BUG:kernel_early_hang_without_any_printk_output | 9 | 9
|
+-------------------------------------------------+--------------+--------------+
/kernel/i386-randconfig-i008-1008/c015a7f0b746d0a7e18b82876bd2b693722479d2
+-------------------------------------------------+--------------+--------------+
| | 3354781a2184 | c015a7f0b746
|
+-------------------------------------------------+--------------+--------------+
| BUG:kernel_early_hang_without_any_printk_output | 9 | 9
|
+-------------------------------------------------+--------------+--------------+
/kernel/i386-randconfig-i006-1008/c015a7f0b746d0a7e18b82876bd2b693722479d2
+-------------------------------------------------+--------------+--------------+
| | 3354781a2184 | c015a7f0b746
|
+-------------------------------------------------+--------------+--------------+
| good_boots | 9 | 7
|
| BUG:kernel_early_hang_without_any_printk_output | 0 | 2
|
+-------------------------------------------------+--------------+--------------+
Thanks,
Fengguang
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