From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753875AbaCGPRg (ORCPT ); Fri, 7 Mar 2014 10:17:36 -0500 Received: from cdptpa-outbound-snat.email.rr.com ([107.14.166.230]:49596 "EHLO cdptpa-oedge-vip.email.rr.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752486AbaCGPME (ORCPT ); Fri, 7 Mar 2014 10:12:04 -0500 Message-Id: <20140307151202.999179448@goodmis.org> User-Agent: quilt/0.61-1 Date: Fri, 07 Mar 2014 10:09:33 -0500 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Ingo Molnar , Frederic Weisbecker , Andrew Morton , Filipe Brandenburger Subject: [for-next][PATCH 13/20] tracing: Evaluate len expression only once in __dynamic_array macro References: <20140307150920.881849073@goodmis.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline; filename=0013-tracing-Evaluate-len-expression-only-once-in-__dynam.patch X-RR-Connecting-IP: 107.14.168.142:25 X-Cloudmark-Score: 0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Filipe Brandenburger Use a temporary variable to store the expansion of the len expression. If the evaluation is expensive, this commit will ensure it is evaluated only once inside ftrace_get_offsets_. Link: http://lkml.kernel.org/r/1393651938-16418-3-git-send-email-filbranden@google.com Signed-off-by: Filipe Brandenburger Signed-off-by: Steven Rostedt --- include/trace/ftrace.h | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/include/trace/ftrace.h b/include/trace/ftrace.h index 2125005..e15ae401 100644 --- a/include/trace/ftrace.h +++ b/include/trace/ftrace.h @@ -361,10 +361,11 @@ ftrace_define_fields_##call(struct ftrace_event_call *event_call) \ #undef __dynamic_array #define __dynamic_array(type, item, len) \ + __item_length = (len) * sizeof(type); \ __data_offsets->item = __data_size + \ offsetof(typeof(*entry), __data); \ - __data_offsets->item |= ((len) * sizeof(type)) << 16; \ - __data_size += (len) * sizeof(type); + __data_offsets->item |= __item_length << 16; \ + __data_size += __item_length; #undef __string #define __string(item, src) __dynamic_array(char, item, \ @@ -376,6 +377,7 @@ static inline notrace int ftrace_get_offsets_##call( \ struct ftrace_data_offsets_##call *__data_offsets, proto) \ { \ int __data_size = 0; \ + int __maybe_unused __item_length; \ struct ftrace_raw_##call __maybe_unused *entry; \ \ tstruct; \ -- 1.8.5.3