Re: [PATCH v8 2/6] powerpc: pSeries/Kconfig: Add qspinlock build config

[Pan Xinhui]

å 2016/12/6 08:58, Boqun Feng åé:
> 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@xxxxxxxxxxxxxxxxxx>
> > ---
> >  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