Re: [PATCH 2/3] cpumask: Introduce DYING mask

[Qais Yousef]

On 03/10/21 15:53, Peter Zijlstra wrote:
> --- a/kernel/cpu.c
> +++ b/kernel/cpu.c
> @@ -160,6 +160,9 @@ static int cpuhp_invoke_callback(unsigne
>       int (*cb)(unsigned int cpu);
>       int ret, cnt;
>  
> +     if (bringup != !cpu_dying(cpu))

nit: this condition is hard to read

> +             set_cpu_dying(cpu, !bringup);

since cpu_dying() will do cpumask_test_cpu(), are we saving  much if we
unconditionally call set_cpu_dying(cpu, !bringup) which performs
cpumask_{set, clear}_cpu()?

> +
>       if (st->fail == state) {
>               st->fail = CPUHP_INVALID;
>               return -EAGAIN;

Thanks

--
Qais yousef