[PATCH] kernel/cpu.c: Add right qualifiers for intel_thermal_interrupt() and cpu_hotplug_pm_sync_init()

[PATCH] kernel/cpu.c: Add right qualifiers for intel_thermal_interrupt() and cpu_hotplug_pm_sync_init()

[Fenghua Yu]

From: Fenghua Yu <fenghua.yu@intel.com>

Add __init for functions alloc_frozen_cpus() and cpu_hotplug_pm_sync_init()
because they are only called during boot time.

Add static for function cpu_hotplug_pm_sync_init() because its scope is limited
in this file only.

Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
---
 kernel/cpu.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/cpu.c b/kernel/cpu.c
index 563f136..cf915b8 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -470,7 +470,7 @@ out:
 	cpu_maps_update_done();
 }
 
-static int alloc_frozen_cpus(void)
+static int __init alloc_frozen_cpus(void)
 {
 	if (!alloc_cpumask_var(&frozen_cpus, GFP_KERNEL|__GFP_ZERO))
 		return -ENOMEM;
@@ -543,7 +543,7 @@ cpu_hotplug_pm_callback(struct notifier_block *nb,
 }
 
 
-int cpu_hotplug_pm_sync_init(void)
+static int __init cpu_hotplug_pm_sync_init(void)
 {
 	pm_notifier(cpu_hotplug_pm_callback, 0);
 	return 0;
-- 
1.6.0.3

Re: [PATCH] kernel/cpu.c: Add right qualifiers for intel_thermal_interrupt() and cpu_hotplug_pm_sync_init()

[Srivatsa S. Bhat]

On 11/11/2011 01:52 AM, Fenghua Yu wrote:
> From: Fenghua Yu <fenghua.yu@intel.com>
> 
> Add __init for functions alloc_frozen_cpus() and cpu_hotplug_pm_sync_init()
> because they are only called during boot time.
> 
> Add static for function cpu_hotplug_pm_sync_init() because its scope is limited
> in this file only.
> 
> Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
> ---
>  kernel/cpu.c |    4 ++--
>  1 files changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/kernel/cpu.c b/kernel/cpu.c
> index 563f136..cf915b8 100644
> --- a/kernel/cpu.c
> +++ b/kernel/cpu.c
> @@ -470,7 +470,7 @@ out:
>  	cpu_maps_update_done();
>  }
> 
> -static int alloc_frozen_cpus(void)
> +static int __init alloc_frozen_cpus(void)
>  {
>  	if (!alloc_cpumask_var(&frozen_cpus, GFP_KERNEL|__GFP_ZERO))
>  		return -ENOMEM;
> @@ -543,7 +543,7 @@ cpu_hotplug_pm_callback(struct notifier_block *nb,
>  }
> 
> 
> -int cpu_hotplug_pm_sync_init(void)
> +static int __init cpu_hotplug_pm_sync_init(void)
>  {
>  	pm_notifier(cpu_hotplug_pm_callback, 0);

pm_notifier() macro will declare a static variable. I agree this won't
be any problem functionality-wise. But it doesn't seem elegant to say
"throw away the function but keep the static variable".
So, if you want to add __init qualifier to this function, I suggest that
you declare the static variable outside the function, and call
register_pm_notifier() in the function, just to ensure it doesn't obscure
things.

And please change the title, it talks about intel_thermal_interrupt()!

Thanks,
Srivatsa S. Bhat

>  	return 0;

RE: [PATCH] kernel/cpu.c: Add right qualifiers for intel_thermal_interrupt() and cpu_hotplug_pm_sync_init()

[Yu, Fenghua]

> > -int cpu_hotplug_pm_sync_init(void)
> > +static int __init cpu_hotplug_pm_sync_init(void)
> >  {
> >  	pm_notifier(cpu_hotplug_pm_callback, 0);
> 
> pm_notifier() macro will declare a static variable. I agree this won't
> be any problem functionality-wise. But it doesn't seem elegant to say
> "throw away the function but keep the static variable".
> So, if you want to add __init qualifier to this function, I suggest
> that
> you declare the static variable outside the function, and call
> register_pm_notifier() in the function, just to ensure it doesn't
> obscure
> things.
> 
Rmoving __init cpu_hotplug_pm_sync_init() function after boot time and keep the static data defined in pm_notifier() is a normal behavior and normal usage in kernel. Same notifier registration usage function examples are ia64_mca_init() and msic_init() in mrst.c. There are quite a few other similar static data in __init functions usage examples in kernel source code.

So I would keep the same code in the patch.

I'll send an updated patch just to change the title typo.

Thanks.

-Fenghua

Re: [PATCH] kernel/cpu.c: Add right qualifiers for intel_thermal_interrupt() and cpu_hotplug_pm_sync_init()

[Srivatsa S. Bhat]

On 11/15/2011 05:32 AM, Yu, Fenghua wrote:
>>> -int cpu_hotplug_pm_sync_init(void)
>>> +static int __init cpu_hotplug_pm_sync_init(void)
>>>  {
>>>  	pm_notifier(cpu_hotplug_pm_callback, 0);
>>
>> pm_notifier() macro will declare a static variable. I agree this won't
>> be any problem functionality-wise. But it doesn't seem elegant to say
>> "throw away the function but keep the static variable".
>> So, if you want to add __init qualifier to this function, I suggest
>> that
>> you declare the static variable outside the function, and call
>> register_pm_notifier() in the function, just to ensure it doesn't
>> obscure
>> things.
>>
> Rmoving __init cpu_hotplug_pm_sync_init() function after boot time and keep the static data defined in pm_notifier() is a normal behavior and normal usage in kernel. Same notifier registration usage function examples are ia64_mca_init() and msic_init() in mrst.c. There are quite a few other similar static data in __init functions usage examples in kernel source code.
> 
> So I would keep the same code in the patch.
>

If that's a well-known practice and is not going to obscure anything,
then I am fine with your patch.

Thanks,
Srivatsa S. Bhat
 
> I'll send an updated patch just to change the title typo.
> 
> Thanks.
> 
> -Fenghua
> 

[PATCH] kernel/cpu.c: Add right qualifiers for intel_thermal_interrupt() and cpu_hotplug_pm_sync_init()

[Fenghua Yu]

From: Fenghua Yu <fenghua.yu@intel.com>

Add __init for functions alloc_frozen_cpus() and cpu_hotplug_pm_sync_init()
because they are only called during boot time.

Add static for function cpu_hotplug_pm_sync_init() because its scope is limited
in this file only.

Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
---
 kernel/cpu.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/cpu.c b/kernel/cpu.c
index 563f136..cf915b8 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -470,7 +470,7 @@ out:
 	cpu_maps_update_done();
 }
 
-static int alloc_frozen_cpus(void)
+static int __init alloc_frozen_cpus(void)
 {
 	if (!alloc_cpumask_var(&frozen_cpus, GFP_KERNEL|__GFP_ZERO))
 		return -ENOMEM;
@@ -543,7 +543,7 @@ cpu_hotplug_pm_callback(struct notifier_block *nb,
 }
 
 
-int cpu_hotplug_pm_sync_init(void)
+static int __init cpu_hotplug_pm_sync_init(void)
 {
 	pm_notifier(cpu_hotplug_pm_callback, 0);
 	return 0;
-- 
1.6.0.3