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Date: Sat, 3 Sep 2016 00:16:58 +0200
From: Peter Zijlstra <peterz@infradead.org>
To: Alan Stern <stern@rowland.harvard.edu>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
        Ingo Molnar <mingo@redhat.com>,
        Felipe Balbi <felipe.balbi@linux.intel.com>,
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Subject: Re: Memory barrier needed with wake_up_process()?
Message-ID: <20160902221658.GO10153@twins.programming.kicks-ass.net>
References: <20160902191857.GL10153@twins.programming.kicks-ass.net>
 <Pine.LNX.4.44L0.1609021526420.2027-100000@iolanthe.rowland.org>
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On Fri, Sep 02, 2016 at 04:16:54PM -0400, Alan Stern wrote:
> Felipe, your tests will show whether my guess was totally off-base.  
> For the new people, Felipe is tracking down a problem that involves
> exactly the code sequence listed at the top of the email, where we know
> that the wakeup routine runs but nevertheless the task sleeps.  At
> least, that's what it looks like at the moment.

What arch are you seeing this on?