Re: [RFC][PATCH 01/13] sched/deadline: Impose global limits on sched_attr::sched_period

[Steven Rostedt]

On Mon, 2 Sep 2019 11:16:23 +0200
Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:

> in sched_dl_period_handler(). And do:
> 
> +	preempt_disable();
> 	max = (u64)READ_ONCE(sysctl_sched_dl_period_max) * NSEC_PER_USEC;
> 	min = (u64)READ_ONCE(sysctl_sched_dl_period_min) * NSEC_PER_USEC;
> +	preempt_enable();

Hmm, I'm curious. Doesn't the preempt_disable/enable() also add
compiler barriers which would remove the need for the READ_ONCE()s here?

-- Steve