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| author | Heiko Carstens <heiko.carstens@de.ibm.com> | 2005-11-07 00:58:38 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2005-11-07 07:53:29 -0800 |
| commit | a4c4af7c8dc1eccdfb8c57e1684f08179b4407e6 (patch) | |
| tree | 210773f292da3ba85818402f1945ee7b14ba8c71 /kernel | |
| parent | cc658cfe3c66a6124b5a8db90cdcdd440201b1dc (diff) | |
| download | lwn-a4c4af7c8dc1eccdfb8c57e1684f08179b4407e6.tar.gz lwn-a4c4af7c8dc1eccdfb8c57e1684f08179b4407e6.zip | |
[PATCH] cpu hoptlug: avoid usage of smp_processor_id() in preemptible code
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.
All the traces start 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.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/sched.c | 3 | ||||
| -rw-r--r-- | kernel/softirq.c | 3 | ||||
| -rw-r--r-- | kernel/softlockup.c | 3 | ||||
| -rw-r--r-- | kernel/workqueue.c | 2 |
4 files changed, 7 insertions, 4 deletions
diff --git a/kernel/sched.c b/kernel/sched.c index b4f4eb613537..013f1448006b 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -4680,7 +4680,8 @@ static int migration_call(struct notifier_block *nfb, unsigned long action, #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 f766b2fc48be..ad3295cdded5 100644 --- a/kernel/softirq.c +++ b/kernel/softirq.c @@ -470,7 +470,8 @@ static int __devinit 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(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 75976209cea7..a2dcceb9437d 100644 --- a/kernel/softlockup.c +++ b/kernel/softlockup.c @@ -123,7 +123,8 @@ cpu_callback(struct notifier_block *nfb, unsigned long action, void *hcpu) #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 7cee222231bc..42df83d7fad2 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -524,7 +524,7 @@ static int __devinit workqueue_cpu_callback(struct notifier_block *nfb, 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; |