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Subject: Re: [RFC][PATCH 11/18] sched: Add p->pi_lock to task_rq_lock()
From: Peter Zijlstra <a.p.zijlstra@chello.nl>
To: Oleg Nesterov <oleg@redhat.com>
Cc: Chris Mason <chris.mason@oracle.com>,
        Frank Rowand <frank.rowand@am.sony.com>, Ingo Molnar <mingo@elte.hu>,
        Thomas Gleixner <tglx@linutronix.de>, Mike Galbraith <efault@gmx.de>,
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        Yong Zhang <yong.zhang0@gmail.com>, linux-kernel@vger.kernel.org
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Date: Wed, 05 Jan 2011 20:33:34 +0100
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On Wed, 2011-01-05 at 19:46 +0100, Oleg Nesterov wrote:

> One purely cosmetic nit,

Fixed those, thanks!

> Hmm, and normalize_rt_tasks(), it could just do task_rq_lock/task_rq_unlock.
> And why it does read_lock_irqsave(tasklist), btw? _irqsave looks unneeded. 

I'm not quite sure, I think we can make that an RCU iteration of the
taskset as well, no need to even hold the task-lock, it would render the
sysrq button useless in the face of a RT fork bomb, but I'm not sure we
really care about that at all.

Ingo, Thomas?