From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 078C6C31E46 for ; Wed, 12 Jun 2019 08:35:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DBA012086A for ; Wed, 12 Jun 2019 08:35:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731694AbfFLIfj (ORCPT ); Wed, 12 Jun 2019 04:35:39 -0400 Received: from smtprelay0021.hostedemail.com ([216.40.44.21]:7082 "EHLO smtprelay.hostedemail.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727241AbfFLIfi (ORCPT ); Wed, 12 Jun 2019 04:35:38 -0400 Received: from filter.hostedemail.com (clb03-v110.bra.tucows.net [216.40.38.60]) by smtprelay06.hostedemail.com (Postfix) with ESMTP id 0AAC818224D63; Wed, 12 Jun 2019 08:35:37 +0000 (UTC) X-Session-Marker: 6A6F6540706572636865732E636F6D X-HE-Tag: coat46_4dee5fffc4c39 X-Filterd-Recvd-Size: 2907 Received: from XPS-9350.home (cpe-23-242-196-136.socal.res.rr.com [23.242.196.136]) (Authenticated sender: joe@perches.com) by omf05.hostedemail.com (Postfix) with ESMTPA; Wed, 12 Jun 2019 08:35:35 +0000 (UTC) Message-ID: <1e403b07f8e9843deb893de156e6c03f53948cca.camel@perches.com> Subject: Re: [PATCH] Input: alps: Drop unlikely before IS_ERR(_OR_NULL) From: Joe Perches To: Pali =?ISO-8859-1?Q?Roh=E1r?= , Dmitry Torokhov Cc: Kefeng Wang , linux-kernel@vger.kernel.org, linux-input@vger.kernel.org Date: Wed, 12 Jun 2019 01:35:34 -0700 In-Reply-To: <20190612071444.5uih6em5o73dbvtf@pali> References: <20190605142428.84784-1-wangkefeng.wang@huawei.com> <20190605142428.84784-5-wangkefeng.wang@huawei.com> <20190605144240.pfrvlgxsdpacpwxf@pali> <36eac452-5477-3670-7980-765d0879ead4@huawei.com> <20190612005913.GJ143729@dtor-ws> <20190612071444.5uih6em5o73dbvtf@pali> Content-Type: text/plain; charset="ISO-8859-1" User-Agent: Evolution 3.30.5-0ubuntu0.18.10.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2019-06-12 at 09:14 +0200, Pali Rohár wrote: > On Tuesday 11 June 2019 17:59:13 Dmitry Torokhov wrote: > > Hi Joe, > > > > On Wed, Jun 05, 2019 at 07:28:53PM -0700, Joe Perches wrote: > > > On Thu, 2019-06-06 at 09:08 +0800, Kefeng Wang wrote: > > > > On 2019/6/5 22:42, Pali Rohár wrote: > > > > > On Wednesday 05 June 2019 22:24:28 Kefeng Wang wrote: > > > > > > IS_ERR(_OR_NULL) already contain an 'unlikely' compiler flag, > > > > > > so no need to do that again from its callers. Drop it. > > > > > Hi! I already reviewed this patch and rejected it, see: > > > > > https://patchwork.kernel.org/patch/10817475/ > > > > OK, please ignore it. > > > > > > I think the stated reason of better readability isn't > > > particularly sensible as the object code produced is > > > actually slightly larger. > > > > > > x86-64 defconfig (gcc 8.3.0) > > > > > > $ size drivers/input/mouse/alps.o* > > > text data bss dec hex filename > > > 29416 56 0 29472 7320 drivers/input/mouse/alps.o.new > > > 29432 56 0 29488 7330 drivers/input/mouse/alps.o.old > > > > If gcc produces worse code for double unlikely, you should probably > > report it to gcc folks, no? Or double unlikely turns into likely? > > Is measured size of stripped or unstripped binary? Plus with or without > debug symbols? Double unlikely version should have more debug symbols > and therefore also larger size. > > But if unstripped version with double unlikely is larger then it is for > sure compiler bug. defconfig so no debug symbols. It's not necessarily a gcc bug as gcc doesn't guarantee compiler repeatability.