Re: [patch V6 12/37] x86/entry: Provide idtentry_entry/exit_cond_rcu()

[Thomas Gleixner]

"Paul E. McKenney" <paul...@kernel.org> writes:
> On Wed, May 20, 2020 at 03:15:31PM -0700, Paul E. McKenney wrote:
> Same patch, but with updated commit log based on IRC discussion
> with Andy.

Fun. I came up with the same thing before going to bed. Just that I
named the function differently: rcu_irq_enter_check_tick()

>  #if defined(CONFIG_TINY_RCU)
>  
> +static inline void tickle_nohz_for_rcu(void)
> +{
> +}
> +
>  static inline void rcu_nmi_enter(void)
>  {
>  }
> @@ -23,6 +27,7 @@ static inline void rcu_nmi_exit(void)
>  }
>  
>  #else
> +extern void tickle_nohz_for_rcu(void);

And I made this a NOP for for !NOHZ_FULL systems and avoided the call if
context tracking is not enabled at boot.

void __rcu_irq_enter_check_tick(void);

static inline void rcu_irq_enter_check_tick(void)
{
        if (context_tracking_enabled())
                __rcu_irq_enter_check_tick();
}

Thanks,

        tglx