From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756734Ab3HaUA7 (ORCPT ); Sat, 31 Aug 2013 16:00:59 -0400 Received: from e31.co.us.ibm.com ([32.97.110.149]:58747 "EHLO e31.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754570Ab3HaUA5 (ORCPT ); Sat, 31 Aug 2013 16:00:57 -0400 Date: Sat, 31 Aug 2013 13:00:44 -0700 From: "Paul E. McKenney" To: Steven Rostedt Cc: linux-kernel@vger.kernel.org, Ingo Molnar , Andrew Morton , Peter Zijlstra , Frederic Weisbecker , Jiri Olsa Subject: Re: [RFC][PATCH 15/18 v2] ftrace/rcu: Mark functions that are RCU unsafe Message-ID: <20130831200044.GU3871@linux.vnet.ibm.com> Reply-To: paulmck@linux.vnet.ibm.com References: <20130831051117.884125230@goodmis.org> <20130831051702.922659300@goodmis.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20130831051702.922659300@goodmis.org> User-Agent: Mutt/1.5.21 (2010-09-15) X-TM-AS-MML: No X-Content-Scanned: Fidelis XPS MAILER x-cbid: 13083120-8236-0000-0000-0000014F5A88 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Aug 31, 2013 at 01:11:32AM -0400, Steven Rostedt wrote: > From: "Steven Rostedt (Red Hat)" > > Some callbacks of the function tracer use rcu_read_lock(). This means that > there's places that can not be traced because RCU is not tracking the CPU > for various reasons (like NO_HZ_FULL and coming back from userspace). > > Thes functions need to be marked so that callbacks that use RCU do not > trace them. > > Cc: Paul E. McKenney > Signed-off-by: Steven Rostedt Reviewed-by: Paul E. McKenney Please let me know if you would like me to take this one. If I don't hear otherwise, I will assume that you are pushing it. Thanx, Paul > --- > kernel/rcutiny.c | 1 + > kernel/rcutree.c | 7 +++++++ > 2 files changed, 8 insertions(+) > > diff --git a/kernel/rcutiny.c b/kernel/rcutiny.c > index aa34411..911a61c 100644 > --- a/kernel/rcutiny.c > +++ b/kernel/rcutiny.c > @@ -173,6 +173,7 @@ void rcu_irq_enter(void) > local_irq_restore(flags); > } > EXPORT_SYMBOL_GPL(rcu_irq_enter); > +FTRACE_UNSAFE_RCU(rcu_irq_enter); > > #ifdef CONFIG_DEBUG_LOCK_ALLOC > > diff --git a/kernel/rcutree.c b/kernel/rcutree.c > index 068de3a..ca53562 100644 > --- a/kernel/rcutree.c > +++ b/kernel/rcutree.c > @@ -53,6 +53,7 @@ > #include > #include > #include > +#include > > #include "rcutree.h" > #include > @@ -373,6 +374,7 @@ static void rcu_eqs_enter_common(struct rcu_dynticks *rdtp, long long oldval, > rcu_lockdep_assert(!lock_is_held(&rcu_sched_lock_map), > "Illegal idle entry in RCU-sched read-side critical section."); > } > +FTRACE_UNSAFE_RCU(rcu_eqs_enter_common); > > /* > * Enter an RCU extended quiescent state, which can be either the > @@ -392,6 +394,7 @@ static void rcu_eqs_enter(bool user) > rdtp->dynticks_nesting -= DYNTICK_TASK_NEST_VALUE; > rcu_eqs_enter_common(rdtp, oldval, user); > } > +FTRACE_UNSAFE_RCU(rcu_eqs_enter); > > /** > * rcu_idle_enter - inform RCU that current CPU is entering idle > @@ -513,6 +516,7 @@ static void rcu_eqs_exit_common(struct rcu_dynticks *rdtp, long long oldval, > idle->pid, idle->comm); /* must be idle task! */ > } > } > +FTRACE_UNSAFE_RCU(rcu_eqs_exit_common); > > /* > * Exit an RCU extended quiescent state, which can be either the > @@ -553,6 +557,7 @@ void rcu_idle_exit(void) > local_irq_restore(flags); > } > EXPORT_SYMBOL_GPL(rcu_idle_exit); > +FTRACE_UNSAFE_RCU(rcu_idle_exit); > > #ifdef CONFIG_RCU_USER_QS > /** > @@ -565,6 +570,7 @@ void rcu_user_exit(void) > { > rcu_eqs_exit(1); > } > +FTRACE_UNSAFE_RCU(rcu_user_exit); > > /** > * rcu_user_exit_after_irq - inform RCU that we won't resume to userspace > @@ -625,6 +631,7 @@ void rcu_irq_enter(void) > rcu_eqs_exit_common(rdtp, oldval, true); > local_irq_restore(flags); > } > +FTRACE_UNSAFE_RCU(rcu_irq_enter); > > /** > * rcu_nmi_enter - inform RCU of entry to NMI context > -- > 1.7.10.4 > >