[External] Re: [PATCH v8 3/3] riscv: store percpu offset into thread_info

[yunhui cui]

Hi Thomas,

On Sat, Jul 4, 2026 at 5:02 AM Thomas Gleixner <tglx at kernel.org> wrote:
>
> On Fri, Jul 03 2026 at 20:28, Yunhui Cui wrote:
> > +
> >  extern struct task_struct *__switch_to(struct task_struct *,
> >                                      struct task_struct *);
> >
> > @@ -122,6 +129,7 @@ do {                                                      \
> >       if (switch_to_should_flush_icache(__next))      \
> >               local_flush_icache_all();               \
> >       __switch_to_envcfg(__next);                     \
> > +     __switch_to_pcpu_offset(__next);                \
>
> Why do you want to go through the indirection of current:
>
> > +static inline void __switch_to_pcpu_offset(struct task_struct *next)
> > +{
> > +#ifdef CONFIG_SMP
> > +     next->thread_info.pcpu_offset = __my_cpu_offset;
> > +#endif
> > +}
>
> instead of using __prev->.....offset, which is right there available?
>

Agreed. current is __prev at this point, and both forms compile to the
same load/store sequence. Passing __prev explicitly is clearer, so I will
copy its pcpu_offset directly to __next.

Thanks,
Yunhui