Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S936849AbXFGVC6 (ORCPT ); Thu, 7 Jun 2007 17:02:58 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754952AbXFGVCv (ORCPT ); Thu, 7 Jun 2007 17:02:51 -0400 Received: from e4.ny.us.ibm.com ([32.97.182.144]:34702 "EHLO e4.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752420AbXFGVCt (ORCPT ); Thu, 7 Jun 2007 17:02:49 -0400 Date: Thu, 7 Jun 2007 14:02:47 -0700 From: "Paul E. McKenney" To: Steven Rostedt Cc: john stultz , Ingo Molnar , Thomas Gleixner , Oleg Nesterov , LKML , Dipankar Sarma , RT Subject: Re: [PATCH RT] convert RCU Preempt tasklet into softirq. Message-ID: <20070607210247.GA9390@linux.vnet.ibm.com> Reply-To: paulmck@linux.vnet.ibm.com References: <1181180051.18444.31.camel@localhost.localdomain> <20070607041411.GB1783@linux.vnet.ibm.com> <1181226138.18444.54.camel@localhost.localdomain> <20070607161754.GA11941@linux.vnet.ibm.com> <1181240819.10408.14.camel@localhost.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1181240819.10408.14.camel@localhost.localdomain> User-Agent: Mutt/1.5.13 (2006-08-11) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3002 Lines: 87 On Thu, Jun 07, 2007 at 02:26:59PM -0400, Steven Rostedt wrote: > Following Dipankar's lead, I converted the tasklet in rcupreempt.c into > a softirq. > > I've compiled and booted with this patch, but ran no other tests. I should be able to run rcutorture on it. > Paul, I'm disappointed, this was so trivial I didn't get a chance to > learn anything ;-) ;-) Some nits below. Thanx, Paul > Signed-off-by: Steven Rostedt > > Index: linux-2.6.21-rt9/include/linux/rcupreempt.h > =================================================================== > --- linux-2.6.21-rt9.orig/include/linux/rcupreempt.h > +++ linux-2.6.21-rt9/include/linux/rcupreempt.h > @@ -63,7 +63,9 @@ extern void rcu_check_callbacks(int cpu, > extern void rcu_restart_cpu(int cpu); > extern long rcu_batches_completed(void); > > -extern void rcu_process_callbacks(unsigned long unused); > +struct softirq_action; > + > +extern void rcu_process_callbacks(struct softirq_action *unused); I don't understand why the above is needed -- interrupt.h is included, and the use of rcu_process_callbacks() follows the definition. > #endif /* __KERNEL__ */ > #endif /* __LINUX_RCUPREEMPT_H */ > Index: linux-2.6.21-rt9/kernel/rcupreempt.c > =================================================================== > --- linux-2.6.21-rt9.orig/kernel/rcupreempt.c > +++ linux-2.6.21-rt9/kernel/rcupreempt.c > @@ -57,7 +57,6 @@ > struct rcu_data { > raw_spinlock_t lock; > long completed; /* Number of last completed batch. */ > - struct tasklet_struct rcu_tasklet; > struct rcu_head *nextlist; > struct rcu_head **nexttail; > struct rcu_head *waitlist; > @@ -255,7 +254,7 @@ void rcu_check_callbacks(int cpu, int us > spin_unlock_irqrestore(&rcu_data.lock, oldirq); > } else { > spin_unlock_irqrestore(&rcu_data.lock, oldirq); > - tasklet_schedule(&rcu_data.rcu_tasklet); > + raise_softirq(RCU_SOFTIRQ); > } > } > > @@ -279,7 +278,7 @@ void rcu_advance_callbacks(int cpu, int > spin_unlock_irqrestore(&rcu_data.lock, oldirq); > } > > -void rcu_process_callbacks(unsigned long unused) > +void rcu_process_callbacks(struct softirq_action *unused) > { > unsigned long flags; > struct rcu_head *next, *list; > @@ -367,7 +366,7 @@ void __init __rcu_init(void) > rcu_data.waittail = &rcu_data.waitlist; > rcu_data.donelist = NULL; > rcu_data.donetail = &rcu_data.donelist; > - tasklet_init(&rcu_data.rcu_tasklet, rcu_process_callbacks, 0UL); > + open_softirq(RCU_SOFTIRQ, rcu_process_callbacks, NULL); > } > > /* > > > - > To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/