Linux Virtualization - Dec 2016 - [PATCH v8 2/6] powerpc: pSeries/Kconfig: Add qspinlock build config

On Mon, Dec 05, 2016 at 10:19:22AM -0500, Pan Xinhui
wrote:
> pSeries/powerNV will use qspinlock from now on.
> 
> Signed-off-by: Pan Xinhui <xinhui.pan at linux.vnet.ibm.com>
> ---
>  arch/powerpc/platforms/pseries/Kconfig | 8 ++++++++
>  1 file changed, 8 insertions(+)
> 
> diff --git a/arch/powerpc/platforms/pseries/Kconfig
b/arch/powerpc/platforms/pseries/Kconfig
> index bec90fb..8a87d06 100644
> --- a/arch/powerpc/platforms/pseries/Kconfig
> +++ b/arch/powerpc/platforms/pseries/Kconfig
Why here? Not arch/powerpc/platforms/Kconfig?
> @@ -23,6 +23,14 @@ config PPC_PSERIES
>  	select PPC_DOORBELL
>  	default y
>  
> +config ARCH_USE_QUEUED_SPINLOCKS
> +	default y
> +	bool "Enable qspinlock"
I think you just enable qspinlock by default for all PPC platforms. I
guess you need to put

	depends on PPC_PSERIES || PPC_POWERNV

here to achieve what you mean in you commit message.

Regards,
Boqun
> +	help
> +	  Enabling this option will let kernel use qspinlock which is a kind of
> +	  fairlock.  It has shown a good performance improvement on x86 and also
ppc
> +	  especially in high contention cases.
> +
>  config PPC_SPLPAR
>  	depends on PPC_PSERIES
>  	bool "Support for shared-processor logical partitions"
> -- 
> 2.4.11
> 
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? 2016/12/6 08:58, Boqun Feng ??:
> On Mon, Dec 05, 2016 at 10:19:22AM -0500, Pan Xinhui wrote:
>> pSeries/powerNV will use qspinlock from now on.
>>
>> Signed-off-by: Pan Xinhui <xinhui.pan at linux.vnet.ibm.com>
>> ---
>>  arch/powerpc/platforms/pseries/Kconfig | 8 ++++++++
>>  1 file changed, 8 insertions(+)
>>
>> diff --git a/arch/powerpc/platforms/pseries/Kconfig
b/arch/powerpc/platforms/pseries/Kconfig
>> index bec90fb..8a87d06 100644
>> --- a/arch/powerpc/platforms/pseries/Kconfig
>> +++ b/arch/powerpc/platforms/pseries/Kconfig
>
> Why here? Not arch/powerpc/platforms/Kconfig?
>
>> @@ -23,6 +23,14 @@ config PPC_PSERIES
>>  	select PPC_DOORBELL
>>  	default y
>>
>> +config ARCH_USE_QUEUED_SPINLOCKS
>> +	default y
>> +	bool "Enable qspinlock"
>
> I think you just enable qspinlock by default for all PPC platforms. I
> guess you need to put
>
> 	depends on PPC_PSERIES || PPC_POWERNV
>
> here to achieve what you mean in you commit message.
>
yes, another good way.
I prefer to put it in pseries/Kconfig as same as pv-qspinlocks config.
when we build nv, it still include pSeries's config anyway.

thanks
xinhui
> Regards,
> Boqun
>
>> +	help
>> +	  Enabling this option will let kernel use qspinlock which is a kind
of
>> +	  fairlock.  It has shown a good performance improvement on x86 and
also ppc
>> +	  especially in high contention cases.
>> +
>>  config PPC_SPLPAR
>>  	depends on PPC_PSERIES
>>  	bool "Support for shared-processor logical partitions"
>> --
>> 2.4.11
>>

? 2016/12/6 09:24, Pan Xinhui ??:
>
>
> ? 2016/12/6 08:58, Boqun Feng ??:
>> On Mon, Dec 05, 2016 at 10:19:22AM -0500, Pan Xinhui wrote:
>>> pSeries/powerNV will use qspinlock from now on.
>>>
>>> Signed-off-by: Pan Xinhui <xinhui.pan at linux.vnet.ibm.com>
>>> ---
>>>  arch/powerpc/platforms/pseries/Kconfig | 8 ++++++++
>>>  1 file changed, 8 insertions(+)
>>>
>>> diff --git a/arch/powerpc/platforms/pseries/Kconfig
b/arch/powerpc/platforms/pseries/Kconfig
>>> index bec90fb..8a87d06 100644
>>> --- a/arch/powerpc/platforms/pseries/Kconfig
>>> +++ b/arch/powerpc/platforms/pseries/Kconfig
>>
>> Why here? Not arch/powerpc/platforms/Kconfig?
>>
>>> @@ -23,6 +23,14 @@ config PPC_PSERIES
>>>      select PPC_DOORBELL
>>>      default y
>>>
>>> +config ARCH_USE_QUEUED_SPINLOCKS
>>> +    default y
>>> +    bool "Enable qspinlock"
>>
>> I think you just enable qspinlock by default for all PPC platforms. I
>> guess you need to put
>>
>>     depends on PPC_PSERIES || PPC_POWERNV
>>
>> here to achieve what you mean in you commit message.
>>
oh, yes, need depends on PPC_PSERIES || PPC_POWERNV.
> yes, another good way.
> I prefer to put it in pseries/Kconfig as same as pv-qspinlocks config.
> when we build nv, it still include pSeries's config anyway.
>
> thanks
> xinhui
>
>> Regards,
>> Boqun
>>
>>> +    help
>>> +      Enabling this option will let kernel use qspinlock which is
a kind of
>>> +      fairlock.  It has shown a good performance improvement on
x86 and also ppc
>>> +      especially in high contention cases.
>>> +
>>>  config PPC_SPLPAR
>>>      depends on PPC_PSERIES
>>>      bool "Support for shared-processor logical
partitions"
>>> --
>>> 2.4.11
>>>