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=-5.6 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 91F7AC433E0 for ; Wed, 22 Jul 2020 06:44:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6166C207BB for ; Wed, 22 Jul 2020 06:44:42 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=web.de header.i=@web.de header.b="YYHXtG9v" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729560AbgGVGol (ORCPT ); Wed, 22 Jul 2020 02:44:41 -0400 Received: from mout.web.de ([217.72.192.78]:58173 "EHLO mout.web.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726736AbgGVGok (ORCPT ); Wed, 22 Jul 2020 02:44:40 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=web.de; s=dbaedf251592; t=1595400271; bh=qdXJ2H2awvG7G9Lnt2ipx4hll8cpX5j5hKL8axwtj74=; h=X-UI-Sender-Class:Subject:To:Cc:References:From:Date:In-Reply-To; b=YYHXtG9vgAMl0RqikVOl+GiFzHkrCvyLNpdfwXQBs4bmqX61umAF/KN8xQmQXsT/L 51UTlGnHVHSxpuCv6jAQjxs/d4O0u3BP5vZE1SYoNGJAuPccaIMW+uek9ihr9NYYhz g5Eknyr/K1QN/mEdfkYjNLCyuS2ybzda33enmt08= X-UI-Sender-Class: c548c8c5-30a9-4db5-a2e7-cb6cb037b8f9 Received: from [192.168.1.2] ([93.131.82.161]) by smtp.web.de (mrweb102 [213.165.67.124]) with ESMTPSA (Nemesis) id 0MNcIg-1jvPjY3094-007ELL; Wed, 22 Jul 2020 08:44:30 +0200 Subject: Re: [v3 2/3] coccinelle: api: extend memdup_user rule with vmemdup_user() To: Julia Lawall , Denis Efremov , Coccinelle Cc: Gilles Muller , Masahiro Yamada , Michal Marek , Nicolas Palix , linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org References: <0b326e2b-723c-3482-c0ef-5d6592a9c6cb@web.de> <07a06754-94dd-60b1-1ad1-9e602c86b1f8@web.de> From: Markus Elfring Autocrypt: addr=Markus.Elfring@web.de; 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Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-GB Content-Transfer-Encoding: quoted-printable X-Provags-ID: V03:K1:pVc2A3E7p9wl9YfeDW7K4gk+6JucGa4pAalQbpBYtfYD+xrBuCc n2Pu1wl17PjVUQRxRinaqGhweV5+QJUkn+Fw7w3cueEAdLVD4IlrdD5GojF5FBD6y0CIO/f JAc+UHUte3qk5Ot3x+zB+4sLelORffc/pewtQ5QDo3c2HDrhyiGwrtACTuwX0FieN5Rq5zC tSEl5mqrPCq2WQGTRF87Q== X-UI-Out-Filterresults: notjunk:1;V03:K0:95i03QYO6bE=:iMqhzajn5U5Ob7WHEN7PAy IT/piLEKT/+i5yM5aGH+6xeALvzXE7oS9CmLWzbVEjRhJogs/AWv7IHUEXDUATCyJAwM2dsEn n4n065bwQtjKXN1S0kkCaDtnhk7HtI5gYt+8WX94pZ99XuARGzEgWc7rXfC3+n9NfOotw2E2x C0uxiOB2mVbJZF21k0gXGlua2O8MS+Xqn5Ynf9zd5d2avJ/QDISrVXhdkoDcAXwGPQtSJnIrU 6T1qiXlYQImDKF56CACnbDvZ9JLjYiX30w5LPE5HZmfXy1ExG7TVF7eAmYWrJYL7Q0BranAOy ZayHxE3niHbCugbn9L+luRijSsMCM5kWtBdC1+A8w2AT0ZTK+kfCO1jv44W6/2jb1VWR0jpwP Ann4C3AHa+WydoS7EXQ0R2DF6m8zaNiZnG1aocLWobltZqyLKIvXspoNU3YNqNd+xTZvv6qm7 rCjPRyrEBcOba/yJfWz6VbAHF+36jDYUUGOYxS2yiiMl/0VFc6uH2gcdYsvNAPJEY8K8cYN36 3bZtS07KiZZ3AXR5vGIQ+cG8eOPI3WRaH7nVEggZCN3I/oOHYa0rI9VNPConxrbXTEMctGqib XmgPSGs7Q0nlyeOIgmmPgIFZ9ibtrTLb/GiPykQwG9v5ODJTbrJ0MWQ8B3YWQdiuVXg9pzbcf e6+PNbb7usjJGYHnDhBTHCol4haOr6dxVP6AGCLKPo8C8GxsDrm9XFiZvAvDfpBi5e8Se98vW eQj44lIPtuf478WG8ThcMfpf0HPQ78Grt5+VtlCkTUSfTKBSDwZloUV8YUOxfB3iBAJ5XqxZD 8CoNWfnew1tUQDxiv4No67Iri1cSPe0/Rf9bREI9FqczzWaluOqe7ad4Fxm1uUANvkXK7THrn xqUqzlDGvfnD6kt0JY1fQeAUVg3iaqHsdxk++dhwm47DUyAsMbiw8lkzQ8ShAjOBJLJDOSrIX McVD9M45Y6y66ufhe737Zj/e20QpCgc7vWUCWv2v+GUn9voIeuyQT6rMjZd257RKvcc7Qq1Y+ sp1ktXeZV4Dg3QOUtVoq4+UaNjCB/UaxbdEX0ibjpI/aqEGNSsfNPOq0RxG8kjk2JnA3VMEVJ 7sU5enGobq0MBlEv7B26JMoUiGR+xnNFfVxTQt20hvWs+K59vanVriV8nZbBHXBymJw0t6D9P Dgc1jC/Mvc4pPjlU2C6kLBR23NuhBx/TV6iNqZaxk7T9nJ/6/rhmY+mt7bbQO3abamh5+BBpu NWTsUx47wd/MLXPheCl/pjACIICPvFWSCBUnA+g== Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org >> Under which circumstances would you begin to care more for involved dif= ferences >> in corresponding run time characteristics? > > When the difference is hours vs seconds. Such a view can be influenced by execution environments in considerable wa= ys. > In this case, there are tradeoffs between the two options, I am trying to improve the awareness for possible software design variatio= ns. > andI don't know which would be faster, I am curious if more contributors would get into the mood to compare data processing approaches a bit more. > but I think it is extremely unlikely that the difference is noticible. But the following effects may be known for the evaluation of a SmPL rule which was combined for two code parts. * The SmPL dependencies are checked only once. * Can the source code search efforts be reduced a bit? > But if you are concerned about it, you are welcome to try. Will anybody become interested to measure the software behaviour exactly? Regards, Markus