From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <51619016.1090001@xenomai.org> Date: Sun, 07 Apr 2013 17:26:14 +0200 From: Gilles Chanteperdrix MIME-Version: 1.0 References: <515DE96F.7080508@xenomai.org> <515FEF85.5010801@web.de> <51606911.7050205@xenomai.org> <51606A47.8000606@web.de> <51618C48.7040505@xenomai.org> <51618D60.80204@web.de> In-Reply-To: <51618D60.80204@web.de> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Subject: Re: [Xenomai] I-pipe on ARM platform. List-Id: Discussions about the Xenomai project List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Jan Kiszka Cc: Xenomai On 04/07/2013 05:14 PM, Jan Kiszka wrote: > On 2013-04-07 17:10, Gilles Chanteperdrix wrote: >> On 04/06/2013 08:32 PM, Jan Kiszka wrote: >> >>> On 2013-04-06 20:27, Gilles Chanteperdrix wrote: >>>>> And it has to map directly to might_fault >>>>> in case CONFIG_IPIPE_DEBUG_CONTEXT is disabled (thus zero overhead). >>>> >>>> That would defeat the purpose of the patch. might_fault can not be >>>> called over non root domains. >>> >>> True. But we should avoid leaving the costly irq-disable/enable and >>> domain checks in production code behind when might_fault actually >>> resolves to a nop. That should be the case for >>> !CONFIG_DEBUG_ATOMIC_SLEEP && !CONFIG_PROVE_LOCKING. >> >> >> I am almost sure I did not have either of these two options enabled when >> I observed the bug. > > Hmm. And CONFIG_PREEMPT_VOLUNTARY? In that case, might_sleep seems to > serve as a voluntary preemption point. >>From what I see, ipipe_root_only is called systematically, even when CONFIG_PREEMPT_VOLUNTARY is disabled. -- Gilles.