* [PATCH] cpu hoptlug: avoid usage of smp_processor_id() in preemptible code
@ 2005-11-01 14:54 Heiko Carstens
2005-11-02 6:48 ` Ingo Molnar
0 siblings, 1 reply; 3+ messages in thread
From: Heiko Carstens @ 2005-11-01 14:54 UTC (permalink / raw)
To: Andrew Morton, linux-kernel
From: Heiko Carstens <heiko.carstens@de.ibm.com>
Replace smp_processor_id() with any_online_cpu(cpu_online_map) in order
to avoid lots of
"BUG: using smp_processor_id() in preemptible [00000001] code:..."
messages in case taking a cpu online fails.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
---
diffstat:
kernel/sched.c | 3 ++-
kernel/softirq.c | 3 ++-
kernel/softlockup.c | 3 ++-
kernel/workqueue.c | 2 +-
4 files changed, 7 insertions(+), 4 deletions(-)
diff --git a/kernel/sched.c b/kernel/sched.c
index 340dd23..d94ceef 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -4680,7 +4680,8 @@ static int migration_call(struct notifie
#ifdef CONFIG_HOTPLUG_CPU
case CPU_UP_CANCELED:
/* Unbind it from offline cpu so it can run. Fall thru. */
- kthread_bind(cpu_rq(cpu)->migration_thread,smp_processor_id());
+ kthread_bind(cpu_rq(cpu)->migration_thread,
+ any_online_cpu(cpu_online_map));
kthread_stop(cpu_rq(cpu)->migration_thread);
cpu_rq(cpu)->migration_thread = NULL;
break;
diff --git a/kernel/softirq.c b/kernel/softirq.c
index f766b2f..ad3295c 100644
--- a/kernel/softirq.c
+++ b/kernel/softirq.c
@@ -470,7 +470,8 @@ static int __devinit cpu_callback(struct
#ifdef CONFIG_HOTPLUG_CPU
case CPU_UP_CANCELED:
/* Unbind so it can run. Fall thru. */
- kthread_bind(per_cpu(ksoftirqd, hotcpu), smp_processor_id());
+ kthread_bind(per_cpu(ksoftirqd, hotcpu),
+ any_online_cpu(cpu_online_map));
case CPU_DEAD:
p = per_cpu(ksoftirqd, hotcpu);
per_cpu(ksoftirqd, hotcpu) = NULL;
diff --git a/kernel/softlockup.c b/kernel/softlockup.c
index 7597620..a2dcceb 100644
--- a/kernel/softlockup.c
+++ b/kernel/softlockup.c
@@ -123,7 +123,8 @@ cpu_callback(struct notifier_block *nfb,
#ifdef CONFIG_HOTPLUG_CPU
case CPU_UP_CANCELED:
/* Unbind so it can run. Fall thru. */
- kthread_bind(per_cpu(watchdog_task, hotcpu), smp_processor_id());
+ kthread_bind(per_cpu(watchdog_task, hotcpu),
+ any_online_cpu(cpu_online_map));
case CPU_DEAD:
p = per_cpu(watchdog_task, hotcpu);
per_cpu(watchdog_task, hotcpu) = NULL;
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 7cee222..42df83d 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -524,7 +524,7 @@ static int __devinit workqueue_cpu_callb
list_for_each_entry(wq, &workqueues, list) {
/* Unbind so it can run. */
kthread_bind(per_cpu_ptr(wq->cpu_wq, hotcpu)->thread,
- smp_processor_id());
+ any_online_cpu(cpu_online_map));
cleanup_workqueue_thread(wq, hotcpu);
}
break;
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] cpu hoptlug: avoid usage of smp_processor_id() in preemptible code
2005-11-01 14:54 [PATCH] cpu hoptlug: avoid usage of smp_processor_id() in preemptible code Heiko Carstens
@ 2005-11-02 6:48 ` Ingo Molnar
2005-11-02 7:07 ` Heiko Carstens
0 siblings, 1 reply; 3+ messages in thread
From: Ingo Molnar @ 2005-11-02 6:48 UTC (permalink / raw)
To: Heiko Carstens; +Cc: Andrew Morton, linux-kernel
* Heiko Carstens <heiko.carstens@de.ibm.com> wrote:
> From: Heiko Carstens <heiko.carstens@de.ibm.com>
>
> Replace smp_processor_id() with any_online_cpu(cpu_online_map) in
> order to avoid lots of "BUG: using smp_processor_id() in preemptible
> [00000001] code:..." messages in case taking a cpu online fails.
could you post the full message, including the stacktrace? I think this
patch just works around the debugging message, and there might be some
real bug to fix.
Ingo
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] cpu hoptlug: avoid usage of smp_processor_id() in preemptible code
2005-11-02 6:48 ` Ingo Molnar
@ 2005-11-02 7:07 ` Heiko Carstens
0 siblings, 0 replies; 3+ messages in thread
From: Heiko Carstens @ 2005-11-02 7:07 UTC (permalink / raw)
To: Ingo Molnar; +Cc: Andrew Morton, linux-kernel
> > From: Heiko Carstens <heiko.carstens@de.ibm.com>
> >
> > Replace smp_processor_id() with any_online_cpu(cpu_online_map) in
> > order to avoid lots of "BUG: using smp_processor_id() in preemptible
> > [00000001] code:..." messages in case taking a cpu online fails.
>
> could you post the full message, including the stacktrace? I think this
> patch just works around the debugging message, and there might be some
> real bug to fix.
>
> Ingo
Sure, all traces start actually at the last notifier_call_chain(...) in
kernel/cpu.c. Since we hold the cpu_control semaphore it shouldn't be
any problem to access cpu_online_map.
The reason why cpu_up failed is simply that the cpu that was supposed to be
taken online wasn't even there. That is because on s390 we never know when
a new cpu comes and therefore cpu_possible_map consists of only ones and
doesn't reflect reality.
Heiko
BUG: using smp_processor_id() in preemptible [00000001] code: bash/1398
caller is migration_call+0x1c8/0x920
000000000d377928 07d9fe4c616704cc 0000000000357d22 0000000000357d22
0000000000015dc8 00000000004e3838 000000000dc6a500 000000000d9c5180
00000000004072e0 0000000000000000 000000000d377888 000000000d3778d8
000000000000000c 000000000032e040 0000000000015dc8 000000000d377888
0000000000000004 0000000000000000 000000000d3779c8 000000000d377928
Call Trace:
([<0000000000015d5c>] show_trace+0xbc/0xd0)
[<0000000000149fb6>] debug_smp_processor_id+0xee/0xf4
[<000000000002ac48>] migration_call+0x1c8/0x920
[<0000000000043292>] notifier_call_chain+0x46/0x84
[<0000000000052c06>] cpu_up+0x16a/0x1c0
[<000000000015bc92>] store_online+0xae/0xe0
[<00000000000d3af0>] sysfs_write_file+0x150/0x1c4
[<000000000008963a>] vfs_write+0xae/0x184
[<000000000008a186>] sys_write+0x52/0x84
[<00000000000211e6>] sysc_do_restart+0x16/0x1c
[<0000020000107e24>] 0x20000107e24
BUG: using smp_processor_id() in preemptible [00000001] code: bash/1398
caller is cpu_callback+0x156/0x360
000000000d377980 000000000d377870 0000000000357d22 0000000000357d22
0000000000015dc8 000000000d374000 000000000dc6a500 0000020000020000
00000000004072e0 0000000000000000 000000000d3778e0 000000000d377930
000000000000000c 000000000032e040 0000000000015dc8 000000000d3778e0
0000000000000004 0000000000000000 000000000d377a20 000000000d377980
Call Trace:
([<0000000000015d5c>] show_trace+0xbc/0xd0)
[<0000000000149fb6>] debug_smp_processor_id+0xee/0xf4
[<0000000000038a4a>] cpu_callback+0x156/0x360
[<0000000000043292>] notifier_call_chain+0x46/0x84
[<0000000000052c06>] cpu_up+0x16a/0x1c0
[<000000000015bc92>] store_online+0xae/0xe0
[<00000000000d3af0>] sysfs_write_file+0x150/0x1c4
[<000000000008963a>] vfs_write+0xae/0x184
[<000000000008a186>] sys_write+0x52/0x84
[<00000000000211e6>] sysc_do_restart+0x16/0x1c
[<0000020000107e24>] 0x20000107e24
BUG: using smp_processor_id() in preemptible [00000001] code: bash/1398
caller is cpu_callback+0x138/0x1c0
000000000d377988 0000000000a2f1b0 0000000000357d22 0000000000357d22
0000000000015dc8 000000000d374000 000000000dc6a500 0000020000020000
00000000004072e0 0000000000000000 000000000d3778e8 000000000d377938
000000000000000c 000000000032e040 0000000000015dc8 000000000d3778e8
0000000000000004 0000000000000000 000000000d377a28 000000000d377988
Call Trace:
([<0000000000015d5c>] show_trace+0xbc/0xd0)
[<0000000000149fb6>] debug_smp_processor_id+0xee/0xf4
[<000000000005c00c>] cpu_callback+0x138/0x1c0
[<0000000000043292>] notifier_call_chain+0x46/0x84
[<0000000000052c06>] cpu_up+0x16a/0x1c0
[<000000000015bc92>] store_online+0xae/0xe0
[<00000000000d3af0>] sysfs_write_file+0x150/0x1c4
[<000000000008963a>] vfs_write+0xae/0x184
[<000000000008a186>] sys_write+0x52/0x84
[<00000000000211e6>] sysc_do_restart+0x16/0x1c
[<0000020000107e24>] 0x20000107e24
BUG: using smp_processor_id() in preemptible [00000001] code: bash/1398
caller is workqueue_cpu_callback+0x17c/0x358
000000000d377978 000000000ebb1280 0000000000357d22 0000000000357d22
0000000000015dc8 000000000d374000 000000000dc6a500 0000000000000009
00000000004072e0 0000000000000000 000000000d3778d8 000000000d377928
000000000000000c 000000000032e040 0000000000015dc8 000000000d3778d8
0000000000000004 0000000000000000 000000000d377a18 000000000d377978
Call Trace:
([<0000000000015d5c>] show_trace+0xbc/0xd0)
[<0000000000149fb6>] debug_smp_processor_id+0xee/0xf4
[<00000000000472ac>] workqueue_cpu_callback+0x17c/0x358
[<0000000000043292>] notifier_call_chain+0x46/0x84
[<0000000000052c06>] cpu_up+0x16a/0x1c0
[<000000000015bc92>] store_online+0xae/0xe0
[<00000000000d3af0>] sysfs_write_file+0x150/0x1c4
[<000000000008963a>] vfs_write+0xae/0x184
[<000000000008a186>] sys_write+0x52/0x84
[<00000000000211e6>] sysc_do_restart+0x16/0x1c
[<0000020000107e24>] 0x20000107e24
BUG: using smp_processor_id() in preemptible [00000001] code: bash/1398
caller is workqueue_cpu_callback+0x17c/0x358
000000000d377978 000000000d377888 0000000000357d22 0000000000357d22
0000000000015dc8 000000000d374000 000000000dc6a500 0000000000000009
00000000004072e0 0000000000000000 000000000d3778d8 000000000d377928
000000000000000c 000000000032e040 0000000000015dc8 000000000d3778d8
0000000000000004 0000000000000000 000000000d377a18 000000000d377978
Call Trace:
([<0000000000015d5c>] show_trace+0xbc/0xd0)
[<0000000000149fb6>] debug_smp_processor_id+0xee/0xf4
[<00000000000472ac>] workqueue_cpu_callback+0x17c/0x358
[<0000000000043292>] notifier_call_chain+0x46/0x84
[<0000000000052c06>] cpu_up+0x16a/0x1c0
[<000000000015bc92>] store_online+0xae/0xe0
[<00000000000d3af0>] sysfs_write_file+0x150/0x1c4
[<000000000008963a>] vfs_write+0xae/0x184
[<000000000008a186>] sys_write+0x52/0x84
[<00000000000211e6>] sysc_do_restart+0x16/0x1c
[<0000020000107e24>] 0x20000107e24
BUG: using smp_processor_id() in preemptible [00000001] code: bash/1398
caller is workqueue_cpu_callback+0x17c/0x358
000000000d377978 000000000d377888 0000000000357d22 0000000000357d22
0000000000015dc8 000000000d374000 000000000dc6a500 0000000000000009
00000000004072e0 0000000000000000 000000000d3778d8 000000000d377928
000000000000000c 000000000032e040 0000000000015dc8 000000000d3778d8
0000000000000004 0000000000000000 000000000d377a18 000000000d377978
Call Trace:
([<0000000000015d5c>] show_trace+0xbc/0xd0)
[<0000000000149fb6>] debug_smp_processor_id+0xee/0xf4
[<00000000000472ac>] workqueue_cpu_callback+0x17c/0x358
[<0000000000043292>] notifier_call_chain+0x46/0x84
[<0000000000052c06>] cpu_up+0x16a/0x1c0
[<000000000015bc92>] store_online+0xae/0xe0
[<00000000000d3af0>] sysfs_write_file+0x150/0x1c4
[<000000000008963a>] vfs_write+0xae/0x184
[<000000000008a186>] sys_write+0x52/0x84
[<00000000000211e6>] sysc_do_restart+0x16/0x1c
[<0000020000107e24>] 0x20000107e24
BUG: using smp_processor_id() in preemptible [00000001] code: bash/1398
caller is workqueue_cpu_callback+0x17c/0x358
000000000d377978 000000000d377888 0000000000357d22 0000000000357d22
0000000000015dc8 000000000d374000 000000000dc6a500 0000000000000009
00000000004072e0 0000000000000000 000000000d3778d8 000000000d377928
000000000000000c 000000000032e040 0000000000015dc8 000000000d3778d8
0000000000000004 0000000000000000 000000000d377a18 000000000d377978
Call Trace:
([<0000000000015d5c>] show_trace+0xbc/0xd0)
[<0000000000149fb6>] debug_smp_processor_id+0xee/0xf4
[<00000000000472ac>] workqueue_cpu_callback+0x17c/0x358
[<0000000000043292>] notifier_call_chain+0x46/0x84
[<0000000000052c06>] cpu_up+0x16a/0x1c0
[<000000000015bc92>] store_online+0xae/0xe0
[<00000000000d3af0>] sysfs_write_file+0x150/0x1c4
[<000000000008963a>] vfs_write+0xae/0x184
[<000000000008a186>] sys_write+0x52/0x84
[<00000000000211e6>] sysc_do_restart+0x16/0x1c
[<0000020000107e24>] 0x20000107e24
BUG: using smp_processor_id() in preemptible [00000001] code: bash/1398
caller is workqueue_cpu_callback+0x17c/0x358
000000000d377978 000000000d377888 0000000000357d22 0000000000357d22
0000000000015dc8 000000000d374000 000000000dc6a500 0000000000000009
00000000004072e0 0000000000000000 000000000d3778d8 000000000d377928
000000000000000c 000000000032e040 0000000000015dc8 000000000d3778d8
0000000000000004 0000000000000000 000000000d377a18 000000000d377978
Call Trace:
([<0000000000015d5c>] show_trace+0xbc/0xd0)
[<0000000000149fb6>] debug_smp_processor_id+0xee/0xf4
[<00000000000472ac>] workqueue_cpu_callback+0x17c/0x358
[<0000000000043292>] notifier_call_chain+0x46/0x84
[<0000000000052c06>] cpu_up+0x16a/0x1c0
[<000000000015bc92>] store_online+0xae/0xe0
[<00000000000d3af0>] sysfs_write_file+0x150/0x1c4
[<000000000008963a>] vfs_write+0xae/0x184
[<000000000008a186>] sys_write+0x52/0x84
[<00000000000211e6>] sysc_do_restart+0x16/0x1c
[<0000020000107e24>] 0x20000107e24
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2005-11-02 7:08 UTC | newest]
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2005-11-01 14:54 [PATCH] cpu hoptlug: avoid usage of smp_processor_id() in preemptible code Heiko Carstens
2005-11-02 6:48 ` Ingo Molnar
2005-11-02 7:07 ` Heiko Carstens
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