From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932215AbaHVOPq (ORCPT ); Fri, 22 Aug 2014 10:15:46 -0400 Received: from mail-we0-f173.google.com ([74.125.82.173]:42037 "EHLO mail-we0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932088AbaHVOPp (ORCPT ); Fri, 22 Aug 2014 10:15:45 -0400 Date: Fri, 22 Aug 2014 17:15:36 +0300 From: Andreea-Cristina Bernat To: a.p.zijlstra@chello.nl, paulus@samba.org, mingo@redhat.com, acme@kernel.org, linux-kernel@vger.kernel.org Cc: paulmck@linux.vnet.ibm.com Subject: [PATCH] kernel: events: callchain: Replace rcu_assign_pointer() with RCU_INIT_POINTER() Message-ID: <20140822141536.GA32051@ada> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The use of "rcu_assign_pointer()" is NULLing out the pointer. According to RCU_INIT_POINTER()'s block comment: "1. This use of RCU_INIT_POINTER() is NULLing out the pointer" it is better to use it instead of rcu_assign_pointer() because it has a smaller overhead. The following Coccinelle semantic patch was used: @@ @@ - rcu_assign_pointer + RCU_INIT_POINTER (..., NULL) Signed-off-by: Andreea-Cristina Bernat --- kernel/events/callchain.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/events/callchain.c b/kernel/events/callchain.c index 97b67df..f2a88de 100644 --- a/kernel/events/callchain.c +++ b/kernel/events/callchain.c @@ -52,7 +52,7 @@ static void release_callchain_buffers(void) struct callchain_cpus_entries *entries; entries = callchain_cpus_entries; - rcu_assign_pointer(callchain_cpus_entries, NULL); + RCU_INIT_POINTER(callchain_cpus_entries, NULL); call_rcu(&entries->rcu_head, release_callchain_buffers_rcu); } -- 1.9.1