From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756266AbaHVMky (ORCPT ); Fri, 22 Aug 2014 08:40:54 -0400 Received: from mail-wi0-f175.google.com ([209.85.212.175]:38645 "EHLO mail-wi0-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756039AbaHVMkx (ORCPT ); Fri, 22 Aug 2014 08:40:53 -0400 Date: Fri, 22 Aug 2014 15:40:44 +0300 From: Andreea-Cristina Bernat To: axboe@kernel.dk, linux-kernel@vger.kernel.org Cc: paulmck@linux.vnet.ibm.com Subject: [PATCH] blk-cgroup: Replace rcu_assign_pointer() with RCU_INIT_POINTER() Message-ID: <20140822124044.GA18828@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 --- block/blk-cgroup.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c index 069bc20..9a95b3f 100644 --- a/block/blk-cgroup.c +++ b/block/blk-cgroup.c @@ -337,7 +337,7 @@ static void blkg_destroy(struct blkcg_gq *blkg) * will. Hint assignment itself can race safely. */ if (rcu_access_pointer(blkcg->blkg_hint) == blkg) - rcu_assign_pointer(blkcg->blkg_hint, NULL); + RCU_INIT_POINTER(blkcg->blkg_hint, NULL); /* * If root blkg is destroyed. Just clear the pointer since root_rl -- 1.9.1