Re: [RFC PATCH v2 3/7] sched/idle: Add poll before enter real idle path

Peter Zijlstra
2017-08-29T12:46:08Z

On Tue, Aug 29, 2017 at 11:46:37AM +0000, Yang Zhang wrote:
> Add poll in do_idle. For UP VM, if there are running task, it will not
> goes into idle path, so we only enable poll in SMP VM.
>
> Signed-off-by: Yang Zhang <yang.zhang.wz@gmail.com>
> Signed-off-by: Quan Xu <quan.xu0@gmail.com>

Broken SoB chain.

> diff --git a/kernel/sched/idle.c b/kernel/sched/idle.c
> index 6c23e30..b374744 100644
> --- a/kernel/sched/idle.c
> +++ b/kernel/sched/idle.c
> @@ -74,6 +74,7 @@ static noinline int __cpuidle cpu_idle_poll(void)
> }
>
> /* Weak implementations for optional arch specific functions */
> +void __weak arch_cpu_idle_poll(void) { }
> void __weak arch_cpu_idle_prepare(void) { }
> void __weak arch_cpu_idle_enter(void) { }

And not a word on why we need a new arch hook. What's wrong with
arch_cpu_idle_enter() for instance?