On 08/07/2012 11:21 PM, Kumar Gala wrote:
>
> On Aug 7, 2012, at 3:43 AM, Zhao Chenhui wrote:
>
>> The cpufreq driver of mpc85xx will disable/enable cpu hotplug temporarily.
>> Therefore, the related functions should be exported.
>>
>> Signed-off-by: Zhao Chenhui <chenhui.z...@freescale.com>
>> ---
>> include/linux/cpu.h | 4 ++++
>> 1 files changed, 4 insertions(+), 0 deletions(-)
>
> Rafael, Srivatsa,
>
> Wanted to get your ack on export these functions for direct calling by arch
> code.
>
Why not just use get_online_cpus()/put_online_cpus()?
In the case of suspend/resume/hibernation, we had introduced these CPU hotplug
disable
functions because we would end up doing CPU hotplug ourselves, further down the
path.
So if we did a get_online_cpus(), we would end up deadlocking ourselves.
Whereas, the
patch 4/4 looks like a straightforward case of wanting to simply disable CPU
hotplug..
I don't see where you are doing CPU hotplug yourself in the path. So IMO, just
get/put_online_cpus() should do.
Regards,
Srivatsa S. Bhat
>
>>
>> diff --git a/include/linux/cpu.h b/include/linux/cpu.h
>> index ce7a074..df8f73d 100644
>> --- a/include/linux/cpu.h
>> +++ b/include/linux/cpu.h
>> @@ -146,6 +146,8 @@ void notify_cpu_starting(unsigned int cpu);
>> extern void cpu_maps_update_begin(void);
>> extern void cpu_maps_update_done(void);
>>
>> +extern void cpu_hotplug_disable_before_freeze(void);
>> +extern void cpu_hotplug_enable_after_thaw(void);
>> #else /* CONFIG_SMP */
>>
>> #define cpu_notifier(fn, pri) do { (void)(fn); } while (0)
>> @@ -167,6 +169,8 @@ static inline void cpu_maps_update_done(void)
>> {
>> }
>>
>> +static inline void cpu_hotplug_disable_before_freeze(void) {}
>> +static inline void cpu_hotplug_enable_after_thaw(void) {}
>> #endif /* CONFIG_SMP */
>> extern struct bus_type cpu_subsys;
>>
>> --
>> 1.6.4.1
>>
>
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