* [PATCH v3] Do not change worker's running cpu in cmci_rediscover().
@ 2012-10-29 3:01 Tang Chen
2012-11-06 11:17 ` Tang Chen
0 siblings, 1 reply; 4+ messages in thread
From: Tang Chen @ 2012-10-29 3:01 UTC (permalink / raw)
To: tony.luck, bp, tglx, mingo, hpa, miaox, laijs, wency, x86,
linux-edac, linux-kernel, bp
cmci_rediscover() used set_cpus_allowed_ptr() to change the current process's
running cpu, and migrate itself to the dest cpu. But worker processes are not
allowed to be migrated. If current is a worker, the worker will be migrated to
another cpu, but the corresponding worker_pool is still on the original cpu.
In this case, the following BUG_ON in try_to_wake_up_local() will be triggered:
BUG_ON(rq != this_rq());
This will cause the kernel panic. The call trace is like the following:
[ 6155.451107] ------------[ cut here ]------------
[ 6155.452019] kernel BUG at kernel/sched/core.c:1654!
......
[ 6155.452019] RIP: 0010:[<ffffffff810add15>] [<ffffffff810add15>] try_to_wake_up_local+0x115/0x130
......
[ 6155.452019] Call Trace:
[ 6155.452019] [<ffffffff8166fc14>] __schedule+0x764/0x880
[ 6155.452019] [<ffffffff81670059>] schedule+0x29/0x70
[ 6155.452019] [<ffffffff8166de65>] schedule_timeout+0x235/0x2d0
[ 6155.452019] [<ffffffff810db57d>] ? mark_held_locks+0x8d/0x140
[ 6155.452019] [<ffffffff810dd463>] ? __lock_release+0x133/0x1a0
[ 6155.452019] [<ffffffff81671c50>] ? _raw_spin_unlock_irq+0x30/0x50
[ 6155.452019] [<ffffffff810db8f5>] ? trace_hardirqs_on_caller+0x105/0x190
[ 6155.452019] [<ffffffff8166fefb>] wait_for_common+0x12b/0x180
[ 6155.452019] [<ffffffff810b0b30>] ? try_to_wake_up+0x2f0/0x2f0
[ 6155.452019] [<ffffffff8167002d>] wait_for_completion+0x1d/0x20
[ 6155.452019] [<ffffffff8110008a>] stop_one_cpu+0x8a/0xc0
[ 6155.452019] [<ffffffff810abd40>] ? __migrate_task+0x1a0/0x1a0
[ 6155.452019] [<ffffffff810a6ab8>] ? complete+0x28/0x60
[ 6155.452019] [<ffffffff810b0fd8>] set_cpus_allowed_ptr+0x128/0x130
[ 6155.452019] [<ffffffff81036785>] cmci_rediscover+0xf5/0x140
[ 6155.452019] [<ffffffff816643c0>] mce_cpu_callback+0x18d/0x19d
[ 6155.452019] [<ffffffff81676187>] notifier_call_chain+0x67/0x150
[ 6155.452019] [<ffffffff810a03de>] __raw_notifier_call_chain+0xe/0x10
[ 6155.452019] [<ffffffff81070470>] __cpu_notify+0x20/0x40
[ 6155.452019] [<ffffffff810704a5>] cpu_notify_nofail+0x15/0x30
[ 6155.452019] [<ffffffff81655182>] _cpu_down+0x262/0x2e0
[ 6155.452019] [<ffffffff81655236>] cpu_down+0x36/0x50
[ 6155.452019] [<ffffffff813d3eaa>] acpi_processor_remove+0x50/0x11e
[ 6155.452019] [<ffffffff813a6978>] acpi_device_remove+0x90/0xb2
[ 6155.452019] [<ffffffff8143cbec>] __device_release_driver+0x7c/0xf0
[ 6155.452019] [<ffffffff8143cd6f>] device_release_driver+0x2f/0x50
[ 6155.452019] [<ffffffff813a7870>] acpi_bus_remove+0x32/0x6d
[ 6155.452019] [<ffffffff813a7932>] acpi_bus_trim+0x87/0xee
[ 6155.452019] [<ffffffff813a7a21>] acpi_bus_hot_remove_device+0x88/0x16b
[ 6155.452019] [<ffffffff813a33ee>] acpi_os_execute_deferred+0x27/0x34
[ 6155.452019] [<ffffffff81090589>] process_one_work+0x219/0x680
[ 6155.452019] [<ffffffff81090528>] ? process_one_work+0x1b8/0x680
[ 6155.452019] [<ffffffff813a33c7>] ? acpi_os_wait_events_complete+0x23/0x23
[ 6155.452019] [<ffffffff810923be>] worker_thread+0x12e/0x320
[ 6155.452019] [<ffffffff81092290>] ? manage_workers+0x110/0x110
[ 6155.452019] [<ffffffff81098396>] kthread+0xc6/0xd0
[ 6155.452019] [<ffffffff8167c4c4>] kernel_thread_helper+0x4/0x10
[ 6155.452019] [<ffffffff81671f30>] ? retint_restore_args+0x13/0x13
[ 6155.452019] [<ffffffff810982d0>] ? __init_kthread_worker+0x70/0x70
[ 6155.452019] [<ffffffff8167c4c0>] ? gs_change+0x13/0x13
This patch removes the set_cpus_allowed_ptr() call, and put the cmci rediscover
jobs onto all the other cpus using system_wq. This could bring some delay for
the jobs.
Change log v1 -> v2:
1) removed patch1, when an online cpu == dying, just continue;
2) rebased on the lastest kernel.
Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
---
arch/x86/kernel/cpu/mcheck/mce_intel.c | 31 ++++++++++++++++++-------------
1 file changed, 18 insertions(+), 13 deletions(-)
diff --git a/arch/x86/kernel/cpu/mcheck/mce_intel.c b/arch/x86/kernel/cpu/mcheck/mce_intel.c
index 5f88abf..4f9a3cb 100644
--- a/arch/x86/kernel/cpu/mcheck/mce_intel.c
+++ b/arch/x86/kernel/cpu/mcheck/mce_intel.c
@@ -285,34 +285,39 @@ void cmci_clear(void)
raw_spin_unlock_irqrestore(&cmci_discover_lock, flags);
}
+static long cmci_rediscover_work_func(void *arg)
+{
+ int banks;
+
+ /* Recheck banks in case CPUs don't all have the same */
+ if (cmci_supported(&banks))
+ cmci_discover(banks);
+
+ return 0;
+}
+
/*
* After a CPU went down cycle through all the others and rediscover
* Must run in process context.
*/
void cmci_rediscover(int dying)
{
- int banks;
- int cpu;
- cpumask_var_t old;
+ int cpu, banks;
if (!cmci_supported(&banks))
return;
- if (!alloc_cpumask_var(&old, GFP_KERNEL))
- return;
- cpumask_copy(old, ¤t->cpus_allowed);
for_each_online_cpu(cpu) {
if (cpu == dying)
continue;
- if (set_cpus_allowed_ptr(current, cpumask_of(cpu)))
+
+ if (cpu == smp_processor_id()) {
+ cmci_rediscover_work_func(NULL);
continue;
- /* Recheck banks in case CPUs don't all have the same */
- if (cmci_supported(&banks))
- cmci_discover(banks);
- }
+ }
- set_cpus_allowed_ptr(current, old);
- free_cpumask_var(old);
+ work_on_cpu(cpu, cmci_rediscover_work_func, NULL);
+ }
}
/*
--
1.7.10.1
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH v3] Do not change worker's running cpu in cmci_rediscover().
2012-10-29 3:01 [PATCH v3] Do not change worker's running cpu in cmci_rediscover() Tang Chen
@ 2012-11-06 11:17 ` Tang Chen
2012-11-06 14:44 ` Borislav Petkov
0 siblings, 1 reply; 4+ messages in thread
From: Tang Chen @ 2012-11-06 11:17 UTC (permalink / raw)
To: tony.luck, bp, tglx, mingo, hpa, miaox, laijs, wency, x86,
linux-edac, linux-kernel, bp
Hi Tony, Borislav,
Would you please help to review this patch ?
Thanks. ;)
On 10/29/2012 11:01 AM, Tang Chen wrote:
> cmci_rediscover() used set_cpus_allowed_ptr() to change the current process's
> running cpu, and migrate itself to the dest cpu. But worker processes are not
> allowed to be migrated. If current is a worker, the worker will be migrated to
> another cpu, but the corresponding worker_pool is still on the original cpu.
>
> In this case, the following BUG_ON in try_to_wake_up_local() will be triggered:
> BUG_ON(rq != this_rq());
>
> This will cause the kernel panic. The call trace is like the following:
>
> [ 6155.451107] ------------[ cut here ]------------
> [ 6155.452019] kernel BUG at kernel/sched/core.c:1654!
> ......
> [ 6155.452019] RIP: 0010:[<ffffffff810add15>] [<ffffffff810add15>] try_to_wake_up_local+0x115/0x130
> ......
> [ 6155.452019] Call Trace:
> [ 6155.452019] [<ffffffff8166fc14>] __schedule+0x764/0x880
> [ 6155.452019] [<ffffffff81670059>] schedule+0x29/0x70
> [ 6155.452019] [<ffffffff8166de65>] schedule_timeout+0x235/0x2d0
> [ 6155.452019] [<ffffffff810db57d>] ? mark_held_locks+0x8d/0x140
> [ 6155.452019] [<ffffffff810dd463>] ? __lock_release+0x133/0x1a0
> [ 6155.452019] [<ffffffff81671c50>] ? _raw_spin_unlock_irq+0x30/0x50
> [ 6155.452019] [<ffffffff810db8f5>] ? trace_hardirqs_on_caller+0x105/0x190
> [ 6155.452019] [<ffffffff8166fefb>] wait_for_common+0x12b/0x180
> [ 6155.452019] [<ffffffff810b0b30>] ? try_to_wake_up+0x2f0/0x2f0
> [ 6155.452019] [<ffffffff8167002d>] wait_for_completion+0x1d/0x20
> [ 6155.452019] [<ffffffff8110008a>] stop_one_cpu+0x8a/0xc0
> [ 6155.452019] [<ffffffff810abd40>] ? __migrate_task+0x1a0/0x1a0
> [ 6155.452019] [<ffffffff810a6ab8>] ? complete+0x28/0x60
> [ 6155.452019] [<ffffffff810b0fd8>] set_cpus_allowed_ptr+0x128/0x130
> [ 6155.452019] [<ffffffff81036785>] cmci_rediscover+0xf5/0x140
> [ 6155.452019] [<ffffffff816643c0>] mce_cpu_callback+0x18d/0x19d
> [ 6155.452019] [<ffffffff81676187>] notifier_call_chain+0x67/0x150
> [ 6155.452019] [<ffffffff810a03de>] __raw_notifier_call_chain+0xe/0x10
> [ 6155.452019] [<ffffffff81070470>] __cpu_notify+0x20/0x40
> [ 6155.452019] [<ffffffff810704a5>] cpu_notify_nofail+0x15/0x30
> [ 6155.452019] [<ffffffff81655182>] _cpu_down+0x262/0x2e0
> [ 6155.452019] [<ffffffff81655236>] cpu_down+0x36/0x50
> [ 6155.452019] [<ffffffff813d3eaa>] acpi_processor_remove+0x50/0x11e
> [ 6155.452019] [<ffffffff813a6978>] acpi_device_remove+0x90/0xb2
> [ 6155.452019] [<ffffffff8143cbec>] __device_release_driver+0x7c/0xf0
> [ 6155.452019] [<ffffffff8143cd6f>] device_release_driver+0x2f/0x50
> [ 6155.452019] [<ffffffff813a7870>] acpi_bus_remove+0x32/0x6d
> [ 6155.452019] [<ffffffff813a7932>] acpi_bus_trim+0x87/0xee
> [ 6155.452019] [<ffffffff813a7a21>] acpi_bus_hot_remove_device+0x88/0x16b
> [ 6155.452019] [<ffffffff813a33ee>] acpi_os_execute_deferred+0x27/0x34
> [ 6155.452019] [<ffffffff81090589>] process_one_work+0x219/0x680
> [ 6155.452019] [<ffffffff81090528>] ? process_one_work+0x1b8/0x680
> [ 6155.452019] [<ffffffff813a33c7>] ? acpi_os_wait_events_complete+0x23/0x23
> [ 6155.452019] [<ffffffff810923be>] worker_thread+0x12e/0x320
> [ 6155.452019] [<ffffffff81092290>] ? manage_workers+0x110/0x110
> [ 6155.452019] [<ffffffff81098396>] kthread+0xc6/0xd0
> [ 6155.452019] [<ffffffff8167c4c4>] kernel_thread_helper+0x4/0x10
> [ 6155.452019] [<ffffffff81671f30>] ? retint_restore_args+0x13/0x13
> [ 6155.452019] [<ffffffff810982d0>] ? __init_kthread_worker+0x70/0x70
> [ 6155.452019] [<ffffffff8167c4c0>] ? gs_change+0x13/0x13
>
> This patch removes the set_cpus_allowed_ptr() call, and put the cmci rediscover
> jobs onto all the other cpus using system_wq. This could bring some delay for
> the jobs.
>
> Change log v1 -> v2:
> 1) removed patch1, when an online cpu == dying, just continue;
> 2) rebased on the lastest kernel.
>
> Signed-off-by: Tang Chen<tangchen@cn.fujitsu.com>
> Signed-off-by: Miao Xie<miaox@cn.fujitsu.com>
> ---
> arch/x86/kernel/cpu/mcheck/mce_intel.c | 31 ++++++++++++++++++-------------
> 1 file changed, 18 insertions(+), 13 deletions(-)
>
> diff --git a/arch/x86/kernel/cpu/mcheck/mce_intel.c b/arch/x86/kernel/cpu/mcheck/mce_intel.c
> index 5f88abf..4f9a3cb 100644
> --- a/arch/x86/kernel/cpu/mcheck/mce_intel.c
> +++ b/arch/x86/kernel/cpu/mcheck/mce_intel.c
> @@ -285,34 +285,39 @@ void cmci_clear(void)
> raw_spin_unlock_irqrestore(&cmci_discover_lock, flags);
> }
>
> +static long cmci_rediscover_work_func(void *arg)
> +{
> + int banks;
> +
> + /* Recheck banks in case CPUs don't all have the same */
> + if (cmci_supported(&banks))
> + cmci_discover(banks);
> +
> + return 0;
> +}
> +
> /*
> * After a CPU went down cycle through all the others and rediscover
> * Must run in process context.
> */
> void cmci_rediscover(int dying)
> {
> - int banks;
> - int cpu;
> - cpumask_var_t old;
> + int cpu, banks;
>
> if (!cmci_supported(&banks))
> return;
> - if (!alloc_cpumask_var(&old, GFP_KERNEL))
> - return;
> - cpumask_copy(old,¤t->cpus_allowed);
>
> for_each_online_cpu(cpu) {
> if (cpu == dying)
> continue;
> - if (set_cpus_allowed_ptr(current, cpumask_of(cpu)))
> +
> + if (cpu == smp_processor_id()) {
> + cmci_rediscover_work_func(NULL);
> continue;
> - /* Recheck banks in case CPUs don't all have the same */
> - if (cmci_supported(&banks))
> - cmci_discover(banks);
> - }
> + }
>
> - set_cpus_allowed_ptr(current, old);
> - free_cpumask_var(old);
> + work_on_cpu(cpu, cmci_rediscover_work_func, NULL);
> + }
> }
>
> /*
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH v3] Do not change worker's running cpu in cmci_rediscover().
2012-11-06 11:17 ` Tang Chen
@ 2012-11-06 14:44 ` Borislav Petkov
2012-11-07 3:46 ` Tang Chen
0 siblings, 1 reply; 4+ messages in thread
From: Borislav Petkov @ 2012-11-06 14:44 UTC (permalink / raw)
To: Tang Chen
Cc: tony.luck, tglx, mingo, hpa, miaox, laijs, wency, x86, linux-edac,
linux-kernel
On Tue, Nov 06, 2012 at 07:17:26PM +0800, Tang Chen wrote:
> Hi Tony, Borislav,
>
> Would you please help to review this patch ?
I'm guessing mingo or hpa haven't pulled yet:
http://marc.info/?l=linux-kernel&m=135163452500984
Thanks.
--
Regards/Gruss,
Boris.
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH v3] Do not change worker's running cpu in cmci_rediscover().
2012-11-06 14:44 ` Borislav Petkov
@ 2012-11-07 3:46 ` Tang Chen
0 siblings, 0 replies; 4+ messages in thread
From: Tang Chen @ 2012-11-07 3:46 UTC (permalink / raw)
To: Borislav Petkov, tony.luck, tglx, mingo, hpa, miaox, laijs, wency,
x86, linux-edac, linux-kernel
On 11/06/2012 10:44 PM, Borislav Petkov wrote:
> On Tue, Nov 06, 2012 at 07:17:26PM +0800, Tang Chen wrote:
>> Hi Tony, Borislav,
>>
>> Would you please help to review this patch ?
>
> I'm guessing mingo or hpa haven't pulled yet:
>
> http://marc.info/?l=linux-kernel&m=135163452500984
Hum, thank you very much for the info. :)
>
> Thanks.
>
^ permalink raw reply [flat|nested] 4+ messages in thread
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2012-10-29 3:01 [PATCH v3] Do not change worker's running cpu in cmci_rediscover() Tang Chen
2012-11-06 11:17 ` Tang Chen
2012-11-06 14:44 ` Borislav Petkov
2012-11-07 3:46 ` Tang Chen
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