From mboxrd@z Thu Jan 1 00:00:00 1970 From: Juergen Beisert Subject: Re: 2.6.26-rt1 Date: Wed, 13 Aug 2008 15:30:32 +0200 Message-ID: <200808131530.33130.jbe@pengutronix.de> References: <200807301101.32417.j.mell@t-online.de> <20080801211117.GD14851@linux.vnet.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: =?iso-8859-1?q?J=FCrgen_Mell?= , Thomas Gleixner , LKML , Steven Rostedt , Ingo Molnar , Clark Williams , Peter Zijlstra , Carsten Emde To: linux-rt-users@vger.kernel.org, paulmck@linux.vnet.ibm.com Return-path: Received: from metis.extern.pengutronix.de ([83.236.181.26]:57564 "EHLO metis.extern.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752512AbYHMNax convert rfc822-to-8bit (ORCPT ); Wed, 13 Aug 2008 09:30:53 -0400 In-Reply-To: <20080801211117.GD14851@linux.vnet.ibm.com> Content-Disposition: inline Sender: linux-rt-users-owner@vger.kernel.org List-ID: On Freitag, 1. August 2008, Paul E. McKenney wrote: > On Wed, Jul 30, 2008 at 11:01:32AM +0200, J=FCrgen Mell wrote: > > On Wednesday, 30. July 2008, Thomas Gleixner wrote: > > > We are pleased to announce the 2.6.26-rt1 tree, which can be > > > downloaded from the location: > > > > I have tried the new kernel and have some good news and some bad ne= ws: > > > > The good news: The machine boots and seems to run without major pro= blems. > > > > The bad news: It produces continuously lots of bug messages in the = error > > logs (cf. attached dmesg.tgz). The error at rtmutex.c:743 was alrea= dy > > present in 2.6.25-rt* when ACPI was enabled. The 'using smp_process= or_id > > () in preemptible code' is new here with 2.6.26. > > > > Machine is an old Athlon XP (single core) on an EPOX mainboard with= VIA > > chipset. > > > > If I can help with testing, please let me know. > > The following patch should clear things up. It is against 2.6.25.8-r= t7, > but should still apply. > > ---------------------------------------------------------------------= --- > > Disable preemption around statistics for RCU boost and unboost calls. > > Signed-off-by: Paul E. McKenney > --- > > rcupreempt-boost.c | 20 ++++++++++++++++---- > 1 file changed, 16 insertions(+), 4 deletions(-) > > diff -urpNa -X dontdiff linux-2.6.25.8-rt7/kernel/rcupreempt-boost.c > linux-2.6.25.8-rt7-preemptfix/kernel/rcupreempt-boost.c --- > linux-2.6.25.8-rt7/kernel/rcupreempt-boost.c 2008-06-24 14:14:52.0000= 00000 > -0700 +++ > linux-2.6.25.8-rt7-preemptfix/kernel/rcupreempt-boost.c 2008-06-24 > 14:38:59.000000000 -0700 @@ -205,11 +205,23 @@ > RCU_BOOST_TRACE_FUNC_DECL(boost_readers) > RCU_BOOST_TRACE_FUNC_DECL(try_unboost_readers) > RCU_BOOST_TRACE_FUNC_DECL(unboost_readers) > RCU_BOOST_TRACE_FUNC_DECL(over_taken) > +static void rcu_trace_boost_boost_called_preempt(void) > +{ > + preempt_disable(); > + rcu_trace_boost_boost_called(RCU_BOOST_ME); > + preempt_enable(); > +} > +static void rcu_trace_boost_unboost_called_preempt(void) > +{ > + preempt_disable(); > + rcu_trace_boost_unboost_called(RCU_BOOST_ME); > + preempt_enable(); > +} > #else /* CONFIG_RCU_TRACE */ > /* These were created by the above macro "RCU_BOOST_TRACE_FUNC_DECL"= */ > -# define rcu_trace_boost_task_boost_called(rbd) do { } while (0) > +# define rcu_trace_boost_task_boost_called_preempt(rbd) do { } while= (0) > # define rcu_trace_boost_task_boosted(rbd) do { } while (0) > -# define rcu_trace_boost_boost_called(rbd) do { } while (0) > +# define rcu_trace_boost_boost_called_preempt(rbd) do { } while (0) > # define rcu_trace_boost_try_boost(rbd) do { } while (0) > # define rcu_trace_boost_boosted(rbd) do { } while (0) > # define rcu_trace_boost_unboost_called(rbd) do { } while (0) > @@ -261,7 +273,7 @@ void __rcu_preempt_boost(void) > > WARN_ON(!current->rcu_read_lock_nesting); > > - rcu_trace_boost_boost_called(RCU_BOOST_ME); > + rcu_trace_boost_boost_called_preempt(); > > /* check to see if we are already boosted */ > if (unlikely(rcu_is_boosted(curr))) > @@ -313,7 +325,7 @@ void __rcu_preempt_unboost(void) > int prio; > unsigned long flags; > > - rcu_trace_boost_unboost_called(RCU_BOOST_ME); > + rcu_trace_boost_unboost_called_preempt(); > > /* if not boosted, then ignore */ > if (likely(!rcu_is_boosted(curr))) > Using this patch on top of 2.6.26-rt1 results into: [...] CC kernel/rcupreempt-boost.o kernel/rcupreempt-boost.c: In function 'rcu_boost_task': kernel/rcupreempt-boost.c:249: error: implicit declaration of function = 'rcu_trace_boost_task_boost_called' kernel/rcupreempt-boost.c: In function '__rcu_preempt_unboost': kernel/rcupreempt-boost.c:328: error: implicit declaration of function = 'rcu_trace_boost_unboost_called_preempt' when CONFIG_PREEMPT_RCU_BOOST is enabled and target is a PowerPC of type MPC5200B. jbe --=20 Dipl.-Ing. Juergen Beisert | http://www.pengutronix.de =A0Pengutronix - Linux Solutions for Science and Industry =A0 Handelsregister: Amtsgericht Hildesheim, HRA 2686 =A0 =A0 =A0 Vertretung Sued/Muenchen, Germany Phone: +49-8766-939 228 | Fax: +49-5121-206917-9 -- 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