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Date: Thu, 5 Oct 2017 17:27:30 +0200 (CEST)
From: Thomas Gleixner <tglx@linutronix.de>
To: Julia Cartwright <julia@ni.com>
cc: Arnaldo Carvalho de Melo <acme@kernel.org>, bigeasy@linutronix.de,
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        Arnaldo Carvalho de Melo <acme@redhat.com>,
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        Sebastian Sanchez <sebastian.sanchez@intel.com>,
        Steven Rostedt <rostedt@goodmis.org>
Subject: Re: [PATCH 1/2] IB/hfi1: Use preempt_{dis,en}able_nort()
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References: <20171003154920.31566-1-acme@kernel.org> <20171003154920.31566-2-acme@kernel.org> <20171005141744.GC21185@jcartwri.amer.corp.natinst.com>
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On Thu, 5 Oct 2017, Julia Cartwright wrote:
> On Tue, Oct 03, 2017 at 12:49:19PM -0300, Arnaldo Carvalho de Melo wrote:
> > -	preempt_disable();
> > +	preempt_disable_nort();
> >  	this_cpu_inc(*sc->buffers_allocated);
> 
> Have you tried this on RT w/ CONFIG_DEBUG_PREEMPT?  I believe that the
> this_cpu_* operations perform a preemption check, which we'd trip.

Good point. Changing this to migrate_disable() would do the trick.

Thanks,

	tglx