From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760707AbaGYP1e (ORCPT ); Fri, 25 Jul 2014 11:27:34 -0400 Received: from e38.co.us.ibm.com ([32.97.110.159]:56931 "EHLO e38.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760616AbaGYP1d (ORCPT ); Fri, 25 Jul 2014 11:27:33 -0400 Date: Fri, 25 Jul 2014 08:27:29 -0700 From: "Paul E. McKenney" To: Pranith Kumar Cc: Josh Triplett , Steven Rostedt , Mathieu Desnoyers , Lai Jiangshan , "open list:READ-COPY UPDATE..." Subject: Re: [PATCH v2 1/2] rcu: Create a function for rcu_nocb_mask boot time setup Message-ID: <20140725152729.GD11241@linux.vnet.ibm.com> Reply-To: paulmck@linux.vnet.ibm.com References: <1406248652-17416-1-git-send-email-bobby.prani@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1406248652-17416-1-git-send-email-bobby.prani@gmail.com> User-Agent: Mutt/1.5.21 (2010-09-15) X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 14072515-1344-0000-0000-0000030ED29A Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jul 24, 2014 at 08:37:31PM -0400, Pranith Kumar wrote: > This commit creates a function rcu_bootup_announce_oddness_nocb(), which handles > allocation of rcu_nocb_mask and setting it according to the kernel configuration > parameters. > > Signed-off-by: Pranith Kumar Much better! One more change called out below. Thanx, Paul > --- > v2: don't break the print string (comment from paulmck) > > kernel/rcu/tree_plugin.h | 61 +++++++++++++++++++++++++++--------------------- > 1 file changed, 35 insertions(+), 26 deletions(-) > > diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h > index c31eb28..520538a 100644 > --- a/kernel/rcu/tree_plugin.h > +++ b/kernel/rcu/tree_plugin.h > @@ -47,6 +47,39 @@ static char __initdata nocb_buf[NR_CPUS * 5]; > #endif /* #ifdef CONFIG_RCU_NOCB_CPU */ > > /* > + * This is a helper for rcu_bootup_announce_oddness(), which takes care of > + * setting up rcu_nocb_mask for nocb specific kernel configuration parameters > + */ > +static void __init rcu_bootup_announce_oddness_nocb(void) > +{ > +#ifndef CONFIG_RCU_NOCB_CPU_NONE > + if (!have_rcu_nocb_mask) { > + zalloc_cpumask_var(&rcu_nocb_mask, GFP_KERNEL); > + have_rcu_nocb_mask = true; > + } > +#ifdef CONFIG_RCU_NOCB_CPU_ZERO > + pr_info("\tOffload RCU callbacks from CPU 0\n"); > + cpumask_set_cpu(0, rcu_nocb_mask); > +#endif /* #ifdef CONFIG_RCU_NOCB_CPU_ZERO */ > +#ifdef CONFIG_RCU_NOCB_CPU_ALL > + pr_info("\tOffload RCU callbacks from all CPUs\n"); > + cpumask_copy(rcu_nocb_mask, cpu_possible_mask); > +#endif /* #ifdef CONFIG_RCU_NOCB_CPU_ALL */ > +#endif /* #ifndef CONFIG_RCU_NOCB_CPU_NONE */ > + if (have_rcu_nocb_mask) { > + if (!cpumask_subset(rcu_nocb_mask, cpu_possible_mask)) { > + pr_info("\tNote: kernel parameter 'rcu_nocbs=' contains nonexistent CPUs.\n"); > + cpumask_and(rcu_nocb_mask, cpu_possible_mask, > + rcu_nocb_mask); > + } > + cpulist_scnprintf(nocb_buf, sizeof(nocb_buf), rcu_nocb_mask); > + pr_info("\tOffload RCU callbacks from CPUs: %s.\n", nocb_buf); > + if (rcu_nocb_poll) > + pr_info("\tPoll for callbacks from no-CBs CPUs.\n"); > + } > +} > + > +/* > * Check the RCU kernel configuration parameters and print informative > * messages about anything out of the ordinary. If you like #ifdef, you > * will love this function. > @@ -86,32 +119,8 @@ static void __init rcu_bootup_announce_oddness(void) > if (nr_cpu_ids != NR_CPUS) > pr_info("\tRCU restricting CPUs from NR_CPUS=%d to nr_cpu_ids=%d.\n", NR_CPUS, nr_cpu_ids); > #ifdef CONFIG_RCU_NOCB_CPU Please also move the above #ifdef into rcu_bootup_announce_oddness_nocb(). The compiler will inline the resulting empty function, and it is cleaner to have all of the NOCB-related #ifdefs in that function. > -#ifndef CONFIG_RCU_NOCB_CPU_NONE > - if (!have_rcu_nocb_mask) { > - zalloc_cpumask_var(&rcu_nocb_mask, GFP_KERNEL); > - have_rcu_nocb_mask = true; > - } > -#ifdef CONFIG_RCU_NOCB_CPU_ZERO > - pr_info("\tOffload RCU callbacks from CPU 0\n"); > - cpumask_set_cpu(0, rcu_nocb_mask); > -#endif /* #ifdef CONFIG_RCU_NOCB_CPU_ZERO */ > -#ifdef CONFIG_RCU_NOCB_CPU_ALL > - pr_info("\tOffload RCU callbacks from all CPUs\n"); > - cpumask_copy(rcu_nocb_mask, cpu_possible_mask); > -#endif /* #ifdef CONFIG_RCU_NOCB_CPU_ALL */ > -#endif /* #ifndef CONFIG_RCU_NOCB_CPU_NONE */ > - if (have_rcu_nocb_mask) { > - if (!cpumask_subset(rcu_nocb_mask, cpu_possible_mask)) { > - pr_info("\tNote: kernel parameter 'rcu_nocbs=' contains nonexistent CPUs.\n"); > - cpumask_and(rcu_nocb_mask, cpu_possible_mask, > - rcu_nocb_mask); > - } > - cpulist_scnprintf(nocb_buf, sizeof(nocb_buf), rcu_nocb_mask); > - pr_info("\tOffload RCU callbacks from CPUs: %s.\n", nocb_buf); > - if (rcu_nocb_poll) > - pr_info("\tPoll for callbacks from no-CBs CPUs.\n"); > - } > -#endif /* #ifdef CONFIG_RCU_NOCB_CPU */ > + rcu_bootup_announce_oddness_nocb(); > +#endif > } > > #ifdef CONFIG_TREE_PREEMPT_RCU > -- > 2.0.1 >