Re: [PATCH 1/2] IB/hfi1: Use preempt_{dis,en}able_nort()

From: Thomas Gleixner
Date: Thu Oct 05 2017 - 11:27:45 EST


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