Re: [PATCH v2 3/3] RISC-V: Support cpu hotplug.

[Atish Patra]

On 8/30/18 11:19 PM, Christoph Hellwig wrote:
> > +#else
> > +static inline bool can_hotplug_cpu(void) { return 0; }
> > +static inline void arch_send_call_wakeup_ipi(int cpu) { }
>
> Please use normal coding style for these stubs.

Done.
> >   #define INTERRUPT_CAUSE_FLAG	(1UL << (__riscv_xlen - 1))
> > +#define get_scause(cause)	(cause & ~INTERRUPT_CAUSE_FLAG)
>
> I think this helper is misleading - the cause includes the interrupt
> flag.  I'd rather open code this in the other place as well.

ok. Done.

> > diff --git a/arch/riscv/kernel/process.c b/arch/riscv/kernel/process.c
> > index d7c6ca7c..cb209139 100644
> > --- a/arch/riscv/kernel/process.c
> > +++ b/arch/riscv/kernel/process.c
> > @@ -42,6 +42,13 @@ void arch_cpu_idle(void)
> >   	local_irq_enable();
> >   }
> >   
> > +#ifdef CONFIG_HOTPLUG_CPU
> > +void arch_cpu_idle_dead(void)
> > +{
> > +	cpu_play_dead();
> > +}
> > +#endif
>
> I wonder if it might be worth to introduce a small
> arch/riscv/kernel/cpu-hotplug.c file for the various CONFIG_HOTPLUG_CPU
> only functions.

I have kept it here to match all other arch. Same goes for all hotplug 
functions in smpboot.c

I can move them to a separate file if you think that provides better 
code readability and structure.


Regards,
Atish