* [patch] KVM, hotplug: export register_cpu_notifier
@ 2007-02-07 8:16 Ingo Molnar
2007-02-07 9:12 ` Avi Kivity
0 siblings, 1 reply; 4+ messages in thread
From: Ingo Molnar @ 2007-02-07 8:16 UTC (permalink / raw)
To: Andrew Morton; +Cc: Avi Kivity, linux-kernel
Subject: [patch] KVM, hotplug: export register_cpu_notifier
From: Ingo Molnar <mingo@elte.hu>
KVM-trunk uses register_cpu_notifier() but it's a module and we only
export this if CONFIG_HOTPLUG_CPU. Export it otherwise too.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
kernel/cpu.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
Index: linux/kernel/cpu.c
===================================================================
--- linux.orig/kernel/cpu.c
+++ linux/kernel/cpu.c
@@ -75,10 +75,10 @@ int __cpuinit register_cpu_notifier(stru
return ret;
}
-#ifdef CONFIG_HOTPLUG_CPU
-
EXPORT_SYMBOL(register_cpu_notifier);
+#ifdef CONFIG_HOTPLUG_CPU
+
void unregister_cpu_notifier(struct notifier_block *nb)
{
mutex_lock(&cpu_add_remove_lock);
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [patch] KVM, hotplug: export register_cpu_notifier
2007-02-07 8:16 [patch] KVM, hotplug: export register_cpu_notifier Ingo Molnar
@ 2007-02-07 9:12 ` Avi Kivity
2007-02-07 9:19 ` Ingo Molnar
0 siblings, 1 reply; 4+ messages in thread
From: Avi Kivity @ 2007-02-07 9:12 UTC (permalink / raw)
To: Ingo Molnar; +Cc: Andrew Morton, linux-kernel
Ingo Molnar wrote:
> Subject: [patch] KVM, hotplug: export register_cpu_notifier
> From: Ingo Molnar <mingo@elte.hu>
>
> KVM-trunk uses register_cpu_notifier() but it's a module and we only
> export this if CONFIG_HOTPLUG_CPU. Export it otherwise too.
>
> Signed-off-by: Ingo Molnar <mingo@elte.hu>
> ---
> kernel/cpu.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> Index: linux/kernel/cpu.c
> ===================================================================
> --- linux.orig/kernel/cpu.c
> +++ linux/kernel/cpu.c
> @@ -75,10 +75,10 @@ int __cpuinit register_cpu_notifier(stru
> return ret;
> }
>
> -#ifdef CONFIG_HOTPLUG_CPU
> -
> EXPORT_SYMBOL(register_cpu_notifier);
>
> +#ifdef CONFIG_HOTPLUG_CPU
> +
> void unregister_cpu_notifier(struct notifier_block *nb)
> {
> mutex_lock(&cpu_add_remove_lock);
>
This is broken: register_cpu_notifier() is __cpuinit, which means it
disappears at module time if !CONFIG_CPU_HOTPLUG.
I submitted a hackaround to Andrew some time ago with the suspend patchset.
--
Do not meddle in the internals of kernels, for they are subtle and quick to panic.
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [patch] KVM, hotplug: export register_cpu_notifier
2007-02-07 9:12 ` Avi Kivity
@ 2007-02-07 9:19 ` Ingo Molnar
2007-02-07 9:34 ` Avi Kivity
0 siblings, 1 reply; 4+ messages in thread
From: Ingo Molnar @ 2007-02-07 9:19 UTC (permalink / raw)
To: Avi Kivity; +Cc: Andrew Morton, linux-kernel
* Avi Kivity <avi@qumranet.com> wrote:
> >-#ifdef CONFIG_HOTPLUG_CPU
> >-
> > EXPORT_SYMBOL(register_cpu_notifier);
> >
> >+#ifdef CONFIG_HOTPLUG_CPU
> >+
> > void unregister_cpu_notifier(struct notifier_block *nb)
> > {
> > mutex_lock(&cpu_add_remove_lock);
> >
>
> This is broken: register_cpu_notifier() is __cpuinit, which means it
> disappears at module time if !CONFIG_CPU_HOTPLUG.
>
> I submitted a hackaround to Andrew some time ago with the suspend
> patchset.
ok. What does your patch do - turns it into an inline? I fixed it up in
-rt via the patch below.
Ingo
---------------------->
Subject: [patch] KVM: export register_cpu_notifier
From: Ingo Molnar <mingo@elte.hu>
KVM-trunk uses register_cpu_notifier() but it's not exported
on CONFIG_HOTPLUG_CPU. Make it a nop inline.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
include/linux/cpu.h | 6 +++++-
kernel/cpu.c | 4 ----
2 files changed, 5 insertions(+), 5 deletions(-)
Index: linux/include/linux/cpu.h
===================================================================
--- linux.orig/include/linux/cpu.h
+++ linux/include/linux/cpu.h
@@ -49,10 +49,14 @@ struct notifier_block;
#ifdef CONFIG_SMP
/* Need to know about CPUs going up/down? */
-extern int register_cpu_notifier(struct notifier_block *nb);
#ifdef CONFIG_HOTPLUG_CPU
+extern int register_cpu_notifier(struct notifier_block *nb);
extern void unregister_cpu_notifier(struct notifier_block *nb);
#else
+static inline int register_cpu_notifier(struct notifier_block *nb)
+{
+ return 0;
+}
static inline void unregister_cpu_notifier(struct notifier_block *nb)
{
}
Index: linux/kernel/cpu.c
===================================================================
--- linux.orig/kernel/cpu.c
+++ linux/kernel/cpu.c
@@ -63,8 +63,6 @@ void unlock_cpu_hotplug(void)
}
EXPORT_SYMBOL_GPL(unlock_cpu_hotplug);
-#endif /* CONFIG_HOTPLUG_CPU */
-
/* Need to know about CPUs going up/down? */
int __cpuinit register_cpu_notifier(struct notifier_block *nb)
{
@@ -75,8 +73,6 @@ int __cpuinit register_cpu_notifier(stru
return ret;
}
-#ifdef CONFIG_HOTPLUG_CPU
-
EXPORT_SYMBOL(register_cpu_notifier);
void unregister_cpu_notifier(struct notifier_block *nb)
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [patch] KVM, hotplug: export register_cpu_notifier
2007-02-07 9:19 ` Ingo Molnar
@ 2007-02-07 9:34 ` Avi Kivity
0 siblings, 0 replies; 4+ messages in thread
From: Avi Kivity @ 2007-02-07 9:34 UTC (permalink / raw)
To: Ingo Molnar; +Cc: Andrew Morton, linux-kernel
Ingo Molnar wrote:
> * Avi Kivity <avi@qumranet.com> wrote:
>
>
>>> -#ifdef CONFIG_HOTPLUG_CPU
>>> -
>>> EXPORT_SYMBOL(register_cpu_notifier);
>>>
>>> +#ifdef CONFIG_HOTPLUG_CPU
>>> +
>>> void unregister_cpu_notifier(struct notifier_block *nb)
>>> {
>>> mutex_lock(&cpu_add_remove_lock);
>>>
>>>
>> This is broken: register_cpu_notifier() is __cpuinit, which means it
>> disappears at module time if !CONFIG_CPU_HOTPLUG.
>>
>> I submitted a hackaround to Andrew some time ago with the suspend
>> patchset.
>>
>
> ok. What does your patch do - turns it into an inline? I fixed it up in
> -rt via the patch below.
>
>
yes, but only if MODULE.
> Ingo
>
> ---------------------->
> Subject: [patch] KVM: export register_cpu_notifier
> From: Ingo Molnar <mingo@elte.hu>
>
> KVM-trunk uses register_cpu_notifier() but it's not exported
> on CONFIG_HOTPLUG_CPU. Make it a nop inline.
>
> Signed-off-by: Ingo Molnar <mingo@elte.hu>
> ---
> include/linux/cpu.h | 6 +++++-
> kernel/cpu.c | 4 ----
> 2 files changed, 5 insertions(+), 5 deletions(-)
>
> Index: linux/include/linux/cpu.h
> ===================================================================
> --- linux.orig/include/linux/cpu.h
> +++ linux/include/linux/cpu.h
> @@ -49,10 +49,14 @@ struct notifier_block;
>
> #ifdef CONFIG_SMP
> /* Need to know about CPUs going up/down? */
> -extern int register_cpu_notifier(struct notifier_block *nb);
> #ifdef CONFIG_HOTPLUG_CPU
> +extern int register_cpu_notifier(struct notifier_block *nb);
> extern void unregister_cpu_notifier(struct notifier_block *nb);
> #else
> +static inline int register_cpu_notifier(struct notifier_block *nb)
> +{
> + return 0;
> +}
> static inline void unregister_cpu_notifier(struct notifier_block *nb)
> {
> }
> Index: linux/kernel/cpu.c
> ===================================================================
> --- linux.orig/kernel/cpu.c
> +++ linux/kernel/cpu.c
> @@ -63,8 +63,6 @@ void unlock_cpu_hotplug(void)
> }
> EXPORT_SYMBOL_GPL(unlock_cpu_hotplug);
>
> -#endif /* CONFIG_HOTPLUG_CPU */
> -
> /* Need to know about CPUs going up/down? */
> int __cpuinit register_cpu_notifier(struct notifier_block *nb)
> {
> @@ -75,8 +73,6 @@ int __cpuinit register_cpu_notifier(stru
> return ret;
> }
>
> -#ifdef CONFIG_HOTPLUG_CPU
> -
> EXPORT_SYMBOL(register_cpu_notifier);
>
> void unregister_cpu_notifier(struct notifier_block *nb)
>
--
Do not meddle in the internals of kernels, for they are subtle and quick to panic.
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2007-02-07 9:35 UTC | newest]
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2007-02-07 8:16 [patch] KVM, hotplug: export register_cpu_notifier Ingo Molnar
2007-02-07 9:12 ` Avi Kivity
2007-02-07 9:19 ` Ingo Molnar
2007-02-07 9:34 ` Avi Kivity
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