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=-4.3 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 327BCC433F5 for ; Wed, 22 Sep 2021 23:51:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 18F7D611C4 for ; Wed, 22 Sep 2021 23:51:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238553AbhIVXwx (ORCPT ); Wed, 22 Sep 2021 19:52:53 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46234 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238526AbhIVXwx (ORCPT ); Wed, 22 Sep 2021 19:52:53 -0400 Received: from mail-pl1-x632.google.com (mail-pl1-x632.google.com [IPv6:2607:f8b0:4864:20::632]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E4D3AC061574; Wed, 22 Sep 2021 16:51:22 -0700 (PDT) Received: by mail-pl1-x632.google.com with SMTP id w11so2808570plz.13; Wed, 22 Sep 2021 16:51:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=message-id:date:mime-version:user-agent:subject:content-language:to :cc:references:from:in-reply-to:content-transfer-encoding; bh=XgsEeLYbI0UodBnr5lEX+ShnspAuT3D7cmzwnoUdmpI=; b=K9gSs3wE0vKD30XeVAtdrlMuNXXyCgj+Bw2AwXWygL82Cb7ahh5TjRL/6p2m42yhqI 8pCejBWe6CpxxEVq6OIe7k6Mv4HWjkJCtsE+buNTRbzRIFD7SsJVgoXFa55acGaEmshy RUmzJNBjFFtIvfw1hSqFrWzknRwugpxzgD4zMaxcE6gkBCOA+uEeAMiL3lVRVw1GpEYk jiKClW13no5FIRrQIgTVVXB5HFhPGJXz3oA0JoQhcc1yATxDEHx95Ni+IKdCrj2Dgdmn Zd2vK9R+23a1L+mDTdP9TooNJR9wWG8kg5QJqL/c1ysTfKF68IG6JqGxsRQPpmLitqaA mv8g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:date:mime-version:user-agent:subject :content-language:to:cc:references:from:in-reply-to :content-transfer-encoding; bh=XgsEeLYbI0UodBnr5lEX+ShnspAuT3D7cmzwnoUdmpI=; b=sJhTxnTyP0UpXa5vns7KhXFl0pMW91e+xEvDpDuC4RaUTM2ynP4lCcwUT1OiBQ0Zmz a1VhkoIqUWk64ZtQ7a4VFFUtYmtRwFi3kOrwSj/eLkTBhX9Y3eq04Ip1RAsHUqSQ2bOh tND/EN889Bik7EXwz2Rurdz89WBAKnFakc7T5VqxuOwClTgdFTYlOymeARdLHzXmSwgy 6TIboAJ2kDr3gwI8rrmvCPsYFC8jfK4TUnbnd8d/92pcouY177WbWaFnLvG7KVy++uGu s5OviPhlMnu38FimtGX580y4nx/h2c1uvt3SE7K/jA1GcQfFiua3DZqGPuIdFaEdNfIN a7dA== X-Gm-Message-State: AOAM533WKvD8IOvj/OtVfh4HfPh7GF3+vtti/sqRhZe2t8eP+m9aY5o2 pXaA5tya1cd8UT7OhCHHKX4= X-Google-Smtp-Source: ABdhPJxSECMetH5CJrAF4QRktI/abljPiV+7Jg0aPgE6MLXfH/WZ9kGeVNzMdiVATS/aFMygi0foVQ== X-Received: by 2002:a17:902:e785:b0:13d:a0a6:4bd with SMTP id cp5-20020a170902e78500b0013da0a604bdmr1589806plb.30.1632354682421; Wed, 22 Sep 2021 16:51:22 -0700 (PDT) Received: from ?IPV6:2600:8802:380b:9e00:5524:2ae2:3f26:1cbf? ([2600:8802:380b:9e00:5524:2ae2:3f26:1cbf]) by smtp.gmail.com with ESMTPSA id g14sm3375410pjk.20.2021.09.22.16.51.21 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 22 Sep 2021 16:51:22 -0700 (PDT) Message-ID: Date: Wed, 22 Sep 2021 16:51:21 -0700 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.1.1 Subject: Re: [PATCH 1/5] initramfs: move unnecessary memcmp from hot path Content-Language: en-US To: Al Viro , David Disseldorp Cc: linux-fsdevel@vger.kernel.org, linux-doc@vger.kernel.org, willy@infradead.org References: <20210922115222.8987-1-ddiss@suse.de> From: Chaitanya Kulkarni In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org On 9/22/2021 4:35 PM, Al Viro wrote: > On Wed, Sep 22, 2021 at 01:52:18PM +0200, David Disseldorp wrote: >> do_header() is called for each cpio entry and first checks for "newc" >> magic before parsing further. The magic check includes a special case >> error message if POSIX.1 ASCII (cpio -H odc) magic is detected. This >> special case POSIX.1 check needn't be done in the hot path, so move it >> under the non-newc-magic error path. > You keep refering to hot paths; do you have any data to support that > assertion? > > How much does that series buy you on average, and what kind of dispersion > do you get before and after it? > > I'm not saying I hate the patches themselves, but those references in commit > messages ping my BS detectors every time I see them ;-/ And this exactly why cover-letter with a quantitative date for such series is important based on my experience...