From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gregoire Gentil Subject: Re: cpufreq + PREEMPT_RT_FULL give bad context sleeping BUG Date: Wed, 27 Mar 2013 08:23:16 -0700 Message-ID: <51530EE4.1040600@gentil.com> References: <20130323013003.GU11538@uudg.org> <514DE3BF.5010800@gentil.com> <20130326205107.GB14220@linutronix.de> <20130326213356.GC14220@linutronix.de> Reply-To: gregoire@gentil.com Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: Sebastian Andrzej Siewior , Linus Walleij , Santosh Shilimkar , Rob Herring , linux-rt-users To: Thomas Gleixner Return-path: Received: from mx1.polytechnique.org ([129.104.30.34]:51215 "EHLO mx1.polytechnique.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751288Ab3C0P3z (ORCPT ); Wed, 27 Mar 2013 11:29:55 -0400 In-Reply-To: Sender: linux-rt-users-owner@vger.kernel.org List-ID: On 03/26/2013 02:44 PM, Thomas Gleixner wrote: > On Tue, 26 Mar 2013, Thomas Gleixner wrote: > >> On Tue, 26 Mar 2013, Sebastian Andrzej Siewior wrote: >> >>> * Thomas Gleixner | 2013-03-26 22:07:45 [+0100]: >>> >>>>> that means it should trigger on mainline as well. >>>> >>>> No. It won't. Mainline uses a spinlock which gets converted to a >>>> sleeping spinlock on rt. >>>> >>>> (rt_spin_lock+0x30/0x64) from (clk_get_rate+0x30/0x54) >>> >>> This is true but this spinlock in only available in the OOT code >>> Gregoire Gentil pointed out ([0]). In mainline we have a mutex in >>> drivers/clk/clk.c and this is what my omap4 blaze is using. >>> >>> [0] http://dev.omapzoom.org/?p=3Dintegration/kernel-ubuntu.git;a=3D= blob;f=3Darch/arm/plat-omap/clock.c;h=3D8c0e8fe2c5c51673e41e4304194d922= dbfaedf38;hb=3D3e1c9f139425663ceee48f92e8d3f23158580334 >> >> Yeah, it's that way in mainline as well. > > I meant, that the mutex is taken. So yes, this will cause a warning i= n > !RT too. Hello, So what could be a tentative solution? Could you advise what I could tr= y? Many thanks in advance, Gr=E9goire -- To unsubscribe from this list: send the line "unsubscribe linux-rt-user= s" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html