Reply-To: xlpang@redhat.com
Subject: Re: [PATCH] sched/deadline: No need to check NULL later_mask
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To: Peter Zijlstra <peterz@infradead.org>
Cc: linux-kernel@vger.kernel.org, Juri Lelli <juri.lelli@arm.com>,
        Ingo Molnar <mingo@redhat.com>, Steven Rostedt <rostedt@goodmis.org>
From: Xunlei Pang <xpang@redhat.com>
Message-ID: <57050A32.9000009@redhat.com>
Date: Wed, 6 Apr 2016 21:08:02 +0800
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On 2016/04/06 at 17:30, Peter Zijlstra wrote:
> 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.

Will do, thanks!

Regards,
Xunlei

>
> Thanks!