Re: [tip:sched/core] sched/idle: Micro-optimize the idle loop

[Peter Zijlstra]

On Thu, Oct 26, 2017 at 02:31:34AM -0700, tip-bot for Cheng Jian wrote:
> After patch (execution in loop):
> 	872:       0f ae e8                lfence

> ARM64:

> After patch (execution in loop):
> 	c84:       d5033d9f        dsb     ld

> @@ -225,7 +226,7 @@ static void do_idle(void)
>  		check_pgt_cache();
>  		rmb();

I never could find a reason for that rmb() to exist, it also lacks a
clarifying comment.

We should perhaps attempt removing that...