From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759614Ab2C2REZ (ORCPT ); Thu, 29 Mar 2012 13:04:25 -0400 Received: from mail-ey0-f174.google.com ([209.85.215.174]:46319 "EHLO mail-ey0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759103Ab2C2REU (ORCPT ); Thu, 29 Mar 2012 13:04:20 -0400 Date: Thu, 29 Mar 2012 19:03:23 +0200 (CEST) From: John Kacur To: Borislav Petkov cc: Steven Rostedt , LKML , Borislav Petkov Subject: Re: [PATCH] ftrace: Remove a superfluous check In-Reply-To: <1333039463-24268-1-git-send-email-bp@amd64.org> Message-ID: References: <1333039463-24268-1-git-send-email-bp@amd64.org> User-Agent: Alpine 2.02 (LFD 1266 2009-07-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 29 Mar 2012, Borislav Petkov wrote: > From: Borislav Petkov > > register_ftrace_function() checks ftrace_disabled and calls > __register_ftrace_function which does it again. > > Drop the first check and add the unlikely hint to the second one. > > No functional change. > > Signed-off-by: Borislav Petkov > --- > kernel/trace/ftrace.c | 6 +----- > 1 file changed, 1 insertion(+), 5 deletions(-) > > diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c > index 867bd1dd2dd0..f9212017406d 100644 > --- a/kernel/trace/ftrace.c > +++ b/kernel/trace/ftrace.c > @@ -311,7 +311,7 @@ static int remove_ftrace_list_ops(struct ftrace_ops **list, > > static int __register_ftrace_function(struct ftrace_ops *ops) > { > - if (ftrace_disabled) > + if (unlikely(ftrace_disabled)) > return -ENODEV; > > if (FTRACE_WARN_ON(ops == &global_ops)) > @@ -4304,14 +4304,10 @@ int register_ftrace_function(struct ftrace_ops *ops) > > mutex_lock(&ftrace_lock); > > - if (unlikely(ftrace_disabled)) > - goto out_unlock; > - > ret = __register_ftrace_function(ops); > if (!ret) > ret = ftrace_startup(ops, 0); > > - > out_unlock: > mutex_unlock(&ftrace_lock); > return ret; > -- If you're going to do this, then you can drop the label too. Thanks John Kacur