From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758595Ab2FOW6s (ORCPT ); Fri, 15 Jun 2012 18:58:48 -0400 Received: from e39.co.us.ibm.com ([32.97.110.160]:36443 "EHLO e39.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758566Ab2FOW6r (ORCPT ); Fri, 15 Jun 2012 18:58:47 -0400 Date: Fri, 15 Jun 2012 15:57:49 -0700 From: "Paul E. McKenney" To: Josh Triplett Cc: linux-kernel@vger.kernel.org, mingo@elte.hu, laijs@cn.fujitsu.com, dipankar@in.ibm.com, akpm@linux-foundation.org, mathieu.desnoyers@polymtl.ca, niv@us.ibm.com, tglx@linutronix.de, peterz@infradead.org, rostedt@goodmis.org, Valdis.Kletnieks@vt.edu, dhowells@redhat.com, eric.dumazet@gmail.com, darren@dvhart.com, fweisbec@gmail.com, patches@linaro.org, "Paul E. McKenney" Subject: Re: [PATCH tip/core/rcu 14/14] rcu: Fix rcu_is_cpu_idle() #ifdef in TINY_RCU Message-ID: <20120615225749.GQ2389@linux.vnet.ibm.com> Reply-To: paulmck@linux.vnet.ibm.com References: <20120615201256.GA26120@linux.vnet.ibm.com> <1339791195-26389-1-git-send-email-paulmck@linux.vnet.ibm.com> <1339791195-26389-14-git-send-email-paulmck@linux.vnet.ibm.com> <20120615212827.GR31184@leaf> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20120615212827.GR31184@leaf> User-Agent: Mutt/1.5.21 (2010-09-15) X-Content-Scanned: Fidelis XPS MAILER x-cbid: 12061522-4242-0000-0000-000001FB5C4F Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jun 15, 2012 at 02:28:28PM -0700, Josh Triplett wrote: > On Fri, Jun 15, 2012 at 01:13:15PM -0700, Paul E. McKenney wrote: > > From: "Paul E. McKenney" > > > > The rcu_is_cpu_idle() function is used if CONFIG_DEBUG_LOCK_ALLOC, > > but TINY_RCU defines it only when CONFIG_PROVE_RCU. This causes > > build failures when CONFIG_DEBUG_LOCK_ALLOC=y but CONFIG_PROVE_RCU=n. > > This commit therefore adjusts the #ifdefs for rcu_is_cpu_idle() so > > that it is defined when CONFIG_DEBUG_LOCK_ALLOC=y. > > > > Signed-off-by: Paul E. McKenney > > Signed-off-by: Paul E. McKenney > > Given that an earlier patch in this series makes rcupdate.h > unconditionally prototype rcu_is_cpu_idle, shouldn't rcutiny.c define it > unconditionally? (And do so before the earlier patch in this series > makes it available unconditionally?) Or update that earlier patch so that it keeps rcu_is_cpu_idle() under #ifdef CONFIG_DEBUG_LOCK_ALLOC. Either way, good catch! Hmmm... I want it under CONFIG_DEBUG_LOCK_ALLOC for TINY_RCU (memory footprint and all that), but unconditional for TREE_RCU. That can be arranged... Thanx, Paul > - Josh Triplett > > > kernel/rcutiny.c | 4 ++-- > > 1 files changed, 2 insertions(+), 2 deletions(-) > > > > diff --git a/kernel/rcutiny.c b/kernel/rcutiny.c > > index 37a5444..547b1fe 100644 > > --- a/kernel/rcutiny.c > > +++ b/kernel/rcutiny.c > > @@ -172,7 +172,7 @@ void rcu_irq_enter(void) > > local_irq_restore(flags); > > } > > > > -#ifdef CONFIG_PROVE_RCU > > +#ifdef CONFIG_DEBUG_LOCK_ALLOC > > > > /* > > * Test whether RCU thinks that the current CPU is idle. > > @@ -183,7 +183,7 @@ int rcu_is_cpu_idle(void) > > } > > EXPORT_SYMBOL(rcu_is_cpu_idle); > > > > -#endif /* #ifdef CONFIG_PROVE_RCU */ > > +#endif /* #ifdef CONFIG_DEBUG_LOCK_ALLOC */ > > > > /* > > * Test whether the current CPU was interrupted from idle. Nested > > -- > > 1.7.8 > > >