Re: [PATCH 1/3] powerpc: copy preempt.h into arch/include/asm

[Christophe Leroy]

Le 02/12/2024 à 15:05, Shrikanth Hegde a écrit :
> On 11/27/24 12:07, Christophe Leroy wrote:
> > Le 25/11/2024 à 05:22, Shrikanth Hegde a écrit :
> > > PowerPC uses asm-generic preempt definitions as of now.
> > > Copy that into arch/asm so that arch specific changes can be done.
> > > This would help the next patch for enabling dynamic preemption.
>
> The reason I want the content instead was to allow future patches where 
> I thought of making preempt count per paca for ppc64 atleast. generic 
> code assumes it is per thread. If this change is to be done at that 
> point, that is fair too. I am okay with it.

I think it is better to keep series minimal and consistent. If you have 
a futur plan, no problem, keep it future and do everything at once 
unless it is heavy and better done in two steps.

As we say in French, a lot of water will have flowed under the bridge by 
then.

I'm sure there will be a lot of discussion when you do that and maybe at 
the end you will end up with something completely different than what 
you have in mind at the moment.

> > Instead of copying all the content of asm-generic version, can you 
> > just create a receptacle for your new macros, that will include asm- 
> > generic/ preempt.h ?
> >
> > Look at arch/powerpc/include/asm/percpu.h for exemple.
>
> You mean something like below right?
>
>
> #ifndef __ASM_POWERPC_PREEMPT_H
> #define __ASM_POWERPC_PREEMPT_H
>
> #include <asm-generic/preempt.h>
>
> #if defined(CONFIG_PREEMPT_DYNAMIC) && 
> defined(CONFIG_HAVE_PREEMPT_DYNAMIC_KEY)
> DECLARE_STATIC_KEY_TRUE(sk_dynamic_irqentry_exit_cond_resched);
> #endif
>
> #endif /* __ASM_POWERPC_PREEMPT_H */

Yes exactly.