Re: [PATCH v2] membarrier: Document scheduler barrier requirements

From	"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Newsgroups	linux.kernel
Subject	Re: [PATCH v2] membarrier: Document scheduler barrier requirements
Date	2017-08-22 08:30 +0200
Message-ID	<uhaRk-6SH-17@gated-at.bofh.it> (permalink)
References	<ug3Ie-54O-1@gated-at.bofh.it> <ugQzg-20E-21@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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On Mon, Aug 21, 2017 at 10:42:36AM +0200, Peter Zijlstra wrote:
> On Fri, Aug 18, 2017 at 09:39:16PM -0700, Mathieu Desnoyers wrote:
> > @@ -3295,6 +3301,9 @@ static void __sched notrace __schedule(bool preempt)
> >  	 * Make sure that signal_pending_state()->signal_pending() below
> >  	 * can't be reordered with __set_current_state(TASK_INTERRUPTIBLE)
> >  	 * done by the caller to avoid the race with signal_wake_up().
> > +	 *
> > +	 * The membarrier system call requires a full memory barrier
> > +	 * after coming from user-space, before storing to rq->curr.
> >  	 */
> >  	smp_mb__before_spinlock();
> >  	rq_lock(rq, &rf);
> 
> Merge conflict here, current tip is over to smp_mb__after_spinlock().

Would some tree other than -rcu be better for that commit?

							Thanx, Paul

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[PATCH v2] membarrier: Document scheduler barrier requirements Mathieu Desnoyers <mathieu.desnoyers@efficios.com> - 2017-08-19 06:40 +0200
  Re: [PATCH v2] membarrier: Document scheduler barrier requirements "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-08-20 07:10 +0200
  Re: [PATCH v2] membarrier: Document scheduler barrier requirements Peter Zijlstra <peterz@infradead.org> - 2017-08-21 10:50 +0200
    Re: [PATCH v2] membarrier: Document scheduler barrier requirements "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-08-22 08:30 +0200

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