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Date: Fri, 23 Sep 2016 11:05:24 +0200
From: Peter Zijlstra <peterz@infradead.org>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: Mikulas Patocka <mpatocka@redhat.com>,
        Mike Snitzer <snitzer@redhat.com>, Alasdair Kergon <agk@redhat.com>,
        Ingo Molnar <mingo@kernel.org>, linux-kernel@vger.kernel.org,
        dm-devel@redhat.com, Joe Thornber <ejt@redhat.com>
Subject: Re: [RFC][PATCH] dm: Remove dm_bufio_cond_resched()
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On Fri, Sep 23, 2016 at 10:00:37AM +0200, Thomas Gleixner wrote:
> On Fri, 23 Sep 2016, Peter Zijlstra wrote:
> > It is, might_sleep() implies might_resched(). In fact, that's all what
> > PREEMPT_VOLUNTARY is, make the might_sleep() debug test imply a resched
> > point.
> 
> Grr, how intuitive - NOT!

No, it actually makes sense. Because you 'obviously' only call
might_sleep() in contexts that should be able to sleep (if not, it'll
holler). So they're already placed right for preemption.