From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755758AbdJJAbV (ORCPT ); Mon, 9 Oct 2017 20:31:21 -0400 Received: from mail.kernel.org ([198.145.29.99]:59750 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754617AbdJJAbT (ORCPT ); Mon, 9 Oct 2017 20:31:19 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 270DE21921 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=goodmis.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=rostedt@goodmis.org Date: Mon, 9 Oct 2017 20:31:16 -0400 From: Steven Rostedt To: "Paul E. McKenney" Cc: linux-kernel@vger.kernel.org, mingo@kernel.org, torvalds@linux-foundation.org, mark.rutland@arm.com, dhowells@redhat.com, linux-arch@vger.kernel.org, peterz@infradead.org, will.deacon@arm.com, Mathieu Desnoyers Subject: Re: [PATCH RFC tip/core/rcu 11/15] tracepoint: Remove smp_read_barrier_depends() from comment Message-ID: <20171009203116.4246818c@gandalf.local.home> In-Reply-To: <1507594969-8347-11-git-send-email-paulmck@linux.vnet.ibm.com> References: <20171010001951.GA6476@linux.vnet.ibm.com> <1507594969-8347-11-git-send-email-paulmck@linux.vnet.ibm.com> X-Mailer: Claws Mail 3.14.0 (GTK+ 2.24.31; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org [ added Mathieu ] On Mon, 9 Oct 2017 17:22:45 -0700 "Paul E. McKenney" wrote: > The comment in tracepoint_add_func() mentions smp_read_barrier_depends(), > whose use should be quite restricted. This commit updates the comment > to instead mention the smp_store_release() and rcu_dereference_sched() > that the current code actually uses. > > Signed-off-by: Paul E. McKenney > Cc: Ingo Molnar > Cc: Steven Rostedt Acked-by: Steven Rostedt (VMware) -- Steve > --- > kernel/tracepoint.c | 9 ++++----- > 1 file changed, 4 insertions(+), 5 deletions(-) > > diff --git a/kernel/tracepoint.c b/kernel/tracepoint.c > index 685c50ae6300..671b13457387 100644 > --- a/kernel/tracepoint.c > +++ b/kernel/tracepoint.c > @@ -212,11 +212,10 @@ static int tracepoint_add_func(struct tracepoint *tp, > } > > /* > - * rcu_assign_pointer has a smp_wmb() which makes sure that the new > - * probe callbacks array is consistent before setting a pointer to it. > - * This array is referenced by __DO_TRACE from > - * include/linux/tracepoints.h. A matching smp_read_barrier_depends() > - * is used. > + * rcu_assign_pointer has as smp_store_release() which makes sure > + * that the new probe callbacks array is consistent before setting > + * a pointer to it. This array is referenced by __DO_TRACE from > + * include/linux/tracepoint.h using rcu_dereference_sched(). > */ > rcu_assign_pointer(tp->funcs, tp_funcs); > if (!static_key_enabled(&tp->key))