From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755072AbbEUMsp (ORCPT ); Thu, 21 May 2015 08:48:45 -0400 Received: from e37.co.us.ibm.com ([32.97.110.158]:40181 "EHLO e37.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753638AbbEUMsn (ORCPT ); Thu, 21 May 2015 08:48:43 -0400 Date: Thu, 21 May 2015 05:48:33 -0700 From: "Paul E. McKenney" To: Will Deacon Cc: "linux-kernel@vger.kernel.org" , "mingo@kernel.org" , "laijs@cn.fujitsu.com" , "dipankar@in.ibm.com" , "akpm@linux-foundation.org" , "mathieu.desnoyers@efficios.com" , "josh@joshtriplett.org" , "tglx@linutronix.de" , "peterz@infradead.org" , "rostedt@goodmis.org" , "dhowells@redhat.com" , "edumazet@google.com" , "dvhart@linux.intel.com" , "fweisbec@gmail.com" , "oleg@redhat.com" , "bobby.prani@gmail.com" , "linux-arm-kernel@lists.infradead.org" , Catalin Marinas Subject: Re: [PATCH tip/core/rcu 7/9] arm64: Use common outgoing-CPU-notification code Message-ID: <20150521124833.GJ6776@linux.vnet.ibm.com> Reply-To: paulmck@linux.vnet.ibm.com References: <20150512214945.GA813@linux.vnet.ibm.com> <1431467407-1223-1-git-send-email-paulmck@linux.vnet.ibm.com> <1431467407-1223-7-git-send-email-paulmck@linux.vnet.ibm.com> <20150521085806.GC21920@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150521085806.GC21920@arm.com> User-Agent: Mutt/1.5.21 (2010-09-15) X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 15052112-0025-0000-0000-00000ACBF18F Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, May 21, 2015 at 09:58:06AM +0100, Will Deacon wrote: > Hi Paul, > > Sorry for being late on this one. No problem! In fact, just in time -- I was going to bug you about this later today. ;-) > On Tue, May 12, 2015 at 10:50:05PM +0100, Paul E. McKenney wrote: > > From: "Paul E. McKenney" > > > > This commit removes the open-coded CPU-offline notification with new > > common code. In particular, this change avoids calling scheduler code > > using RCU from an offline CPU that RCU is ignoring. This is a minimal > > change. A more intrusive change might invoke the cpu_check_up_prepare() > > and cpu_set_state_online() functions at CPU-online time, which would > > allow onlining throw an error if the CPU did not go offline properly. > > > > Signed-off-by: Paul E. McKenney > > Cc: linux-arm-kernel@lists.infradead.org > > Cc: Catalin Marinas > > Cc: Will Deacon > > --- > > arch/arm64/kernel/smp.c | 6 ++---- > > 1 file changed, 2 insertions(+), 4 deletions(-) > > I don't have a better idea, so: > > Acked-by: Will Deacon > > Is this queued via -tip already, or can we pick it into the arm64 tree > for 4.2? Feel free to take it into the arm64 tree. Just let me know, and I will drop it from my tree. Now I only need to bug the arm32 guys. ;-) Thanx, Paul > Cheers, > > Will > > > diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c > > index 2cb008177252..a899c1beff54 100644 > > --- a/arch/arm64/kernel/smp.c > > +++ b/arch/arm64/kernel/smp.c > > @@ -253,15 +253,13 @@ static int op_cpu_kill(unsigned int cpu) > > return cpu_ops[cpu]->cpu_kill(cpu); > > } > > > > -static DECLARE_COMPLETION(cpu_died); > > - > > /* > > * called on the thread which is asking for a CPU to be shutdown - > > * waits until shutdown has completed, or it is timed out. > > */ > > void __cpu_die(unsigned int cpu) > > { > > - if (!wait_for_completion_timeout(&cpu_died, msecs_to_jiffies(5000))) { > > + if (!cpu_wait_death(cpu, 5)) { > > pr_crit("CPU%u: cpu didn't die\n", cpu); > > return; > > } > > @@ -294,7 +292,7 @@ void cpu_die(void) > > local_irq_disable(); > > > > /* Tell __cpu_die() that this CPU is now safe to dispose of */ > > - complete(&cpu_died); > > + (void)cpu_report_death(); > > > > /* > > * Actually shutdown the CPU. This must never fail. The specific hotplug > > -- > > 1.8.1.5 > > >