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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id DAEF9C433F5 for ; Wed, 13 Oct 2021 17:46:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B171D6101D for ; Wed, 13 Oct 2021 17:46:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231228AbhJMRsO (ORCPT ); Wed, 13 Oct 2021 13:48:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39828 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238146AbhJMRsJ (ORCPT ); Wed, 13 Oct 2021 13:48:09 -0400 Received: from mail-il1-x133.google.com (mail-il1-x133.google.com [IPv6:2607:f8b0:4864:20::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3F73FC061570 for ; Wed, 13 Oct 2021 10:46:06 -0700 (PDT) Received: by mail-il1-x133.google.com with SMTP id j8so556188ila.11 for ; Wed, 13 Oct 2021 10:46:06 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20210112.gappssmtp.com; s=20210112; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=7fEZ5rnBRdDspyoejLNWPyy1H9Xqf8tOCmcYbMpo85k=; b=mXnSN+RPQ4Q5oYQSCR3SkrX4e9F30cy07XrTn8iVPHc2se7QjKnLwj96ddt204RHcw u7fCZFzN1PhLsBJlcy8Vra2DJbHomC7C+OwHAcDW9G71eIw9m3AdoGhRAwOwyvAa/9a8 PiWX5SbhOSNvBrG0DhG7WcUNkWTXTqRs6Uv/M3kh3w0V/7X3SdzO39JbUjJwkb6LKRr0 +7EiE8wx5DaSHwshpPhOErb9NRzUBLeJ/fmCOc7r7ojpRuJ7LGSR2rTpzXqXGWbZ1XKF R3/C/C5eIjKOrEPAGEOho39QmH0XiGG/VA1M06/f1TbHw1r3R9UwQDBOdHIzGDaS2cuj 8cxQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=7fEZ5rnBRdDspyoejLNWPyy1H9Xqf8tOCmcYbMpo85k=; b=SbfckOzv5QvNLY+92o7aeq9ZVcuVCI+XjwxlTpMkALuzc/+od2IGlN5VTirtkvIteE EcSIhB25QMv1xl+kQIrFkK0O20XHYDLv7SEpFs5Y4OqpiLliZOKMjqv8tqIXDbsGyjun 7482zMkwqRPUepZ1J2wvswczMAjKKEVnqcDi/fw3mvUeKzQwylyy6MI2Owfmx5Y14Ubj iaWn/ztmX+sdHfIdTqJdwwtszSQMtGtkpIJ364NKsrZ/rvqNBKGOY+dH+enxNmxJs9RB SQA/fzMOC31Jc9m2j932s5pnOxC6QqAMcnNaF+Je3w4SsbRgHSbR5qbWtG8jCUkI11xW KOwQ== X-Gm-Message-State: AOAM532WzKSDx5rwvUZ/rY7NRhdi2dN+XIXOcgnhPE/57aHV6KP2205t iZ1/wQKMcI+e4w+LiywCMnKgmEHrKua4CQ== X-Google-Smtp-Source: ABdhPJxlgbJ3L+9pvMa2YRQh21OhZUW0mYTiyYHzpNv4NcCr4dMslMjERkqamLo1kURgQAdBfKHQ4w== X-Received: by 2002:a05:6e02:14d3:: with SMTP id o19mr378564ilk.156.1634147165349; Wed, 13 Oct 2021 10:46:05 -0700 (PDT) Received: from [192.168.1.30] ([207.135.234.126]) by smtp.gmail.com with ESMTPSA id m10sm89661ila.13.2021.10.13.10.46.04 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 13 Oct 2021 10:46:05 -0700 (PDT) Subject: Re: [PATCH 2/4] block: inline fast path of driver tag allocation To: Christoph Hellwig Cc: linux-block@vger.kernel.org References: <20211013164937.985367-1-axboe@kernel.dk> <20211013164937.985367-3-axboe@kernel.dk> From: Jens Axboe Message-ID: Date: Wed, 13 Oct 2021 11:46:04 -0600 User-Agent: Mozilla/5.0 (X11; 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-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On 10/13/21 11:22 AM, Christoph Hellwig wrote: > On Wed, Oct 13, 2021 at 10:49:35AM -0600, Jens Axboe wrote: >> If we don't use an IO scheduler or have shared tags, then we don't need >> to call into this external function at all. This saves ~2% for such >> a setup. > > Hmm. What happens if you just throw an inline tag onto > blk_mq_get_driver_tag? I'd be surprised if that's any different than my patch in terms of performance, the fast path would be about the same. I don't feel strongly about it, can do that instead. -- Jens Axboe