Date: Wed, 6 Apr 2016 11:30:36 +0200
From: Peter Zijlstra <peterz@infradead.org>
To: xlpang@redhat.com
Cc: linux-kernel@vger.kernel.org, Juri Lelli <juri.lelli@arm.com>,
        Ingo Molnar <mingo@redhat.com>, Steven Rostedt <rostedt@goodmis.org>
Subject: Re: [PATCH] sched/deadline: No need to check NULL later_mask
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On Sat, Apr 02, 2016 at 06:14:28PM +0800, Xunlei Pang wrote:
> Your proposal is very nice!
> 
> At the sched_init() stage we only have one (to be "idle") task and with irq disabled,
> no scheduling will happen, and the cpu_possible_mask was already initiated, so it's
> safe to simply move them there.
> 
> Also, how about rt&deadline sharing a percpu mask? Because only one of them can
> use the mask at a moment, operations are always under some spin_lock_irqsave().
> 
> I made a new patch below, slightly tested by running tens of rt&dl tasks for a while,
> are you fine with it?

Yep, looks fine. Please submit as a proper patch.

Thanks!