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=-5.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,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 B6D5DC5519F for ; Wed, 18 Nov 2020 15:58:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 43B0E247BC for ; Wed, 18 Nov 2020 15:58:03 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=kernel-dk.20150623.gappssmtp.com header.i=@kernel-dk.20150623.gappssmtp.com header.b="cLBFqLch" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727772AbgKRP50 (ORCPT ); Wed, 18 Nov 2020 10:57:26 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52734 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726697AbgKRP50 (ORCPT ); Wed, 18 Nov 2020 10:57:26 -0500 Received: from mail-pg1-x541.google.com (mail-pg1-x541.google.com [IPv6:2607:f8b0:4864:20::541]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1061AC0613D4 for ; Wed, 18 Nov 2020 07:57:26 -0800 (PST) Received: by mail-pg1-x541.google.com with SMTP id t37so1390944pga.7 for ; Wed, 18 Nov 2020 07:57:26 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20150623.gappssmtp.com; s=20150623; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=aYoULJBLjYGf/KnqfWyFT8lv8s/n50oQRcou8Xw75Ww=; b=cLBFqLchvcrUH3Zu4Uj8bOR4y04RQu9MUrmHxnwUP0h5Quwcf9UB5Z033XjW0wPDgz Z7vEZOtExQX4I7Hp/jonp8DgxeT70EWqcTxxaWC9onpU5krj0HKnadRqnk+vOCHJZsYO EfetRUXmARI7r42v/BJf/nrQ4v2wMJwX4J+m+2qezQlcsaGXbYuQZYHhOLqMPbo5WZ4L Ks2CDKcRUyjHU/jLu6sII5SBHyE261OTuv3yevB7bW50Xj8XRBgsB1b5poPWFvycqITx 97pCDuePjQNpxW0yYE7xSZOPfuWB2zYgrX93fan5lWjdGxD9XgqI9WV8Dt4hmfIVdvL8 r9xQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; 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=aYoULJBLjYGf/KnqfWyFT8lv8s/n50oQRcou8Xw75Ww=; b=m6VmIx8W7YO7L0vIYmPZyZdHzwx3cOAALCUhHxGsSocOQsDE/KskoiCsv9Q8TjpUnE if20J7qr15EkFITkjY6Q95Ot6g1YfqMWeXdI3owuflRs8xZxd6aksAuMY8/Aqj6Zt88r bpM+cDy0EeAy4hTV6KzvpduqbxHUHgXHBRF+sK5dHmDrq47agP9cKevaCIOCWARe7pQv OJrf1BX072zAglatxpxxONzK5/NuEQ+GKCguHjzSpD9wvPc+lI8hjpBAcylo0Cvd6bkO 1TCQU2D8XW7sKTUmYTrmairBWUgZE8t3R9P3/J4OidHskbf9QCmmyt3bJuZ0ZuJkSYKK +W1A== X-Gm-Message-State: AOAM533zbwz+LpAs3aYz7MCwy+tCae3/HEA5gdjCb9Isc+VW3urcZDiL ginIFv7sCQ+wcv+pWUnKDot7Tg== X-Google-Smtp-Source: ABdhPJzv/1OFAb/EUWVPFWBWDL9WYPrmUkagXaAX2rHAvBATQIpTkrTxd8QlTu6PKSRpHaWnvlg4sA== X-Received: by 2002:a63:7703:: with SMTP id s3mr9118331pgc.9.1605715045522; Wed, 18 Nov 2020 07:57:25 -0800 (PST) Received: from [192.168.1.134] ([66.219.217.173]) by smtp.gmail.com with ESMTPSA id 85sm26069623pfa.204.2020.11.18.07.57.24 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 18 Nov 2020 07:57:24 -0800 (PST) Subject: Re: [PATCH 5.11 2/2] io_uring: don't take percpu_ref operations for registered files in IOPOLL mode To: Pavel Begunkov , Xiaoguang Wang , io-uring@vger.kernel.org Cc: joseph.qi@linux.alibaba.com References: <20201117061723.18131-1-xiaoguang.wang@linux.alibaba.com> <20201117061723.18131-3-xiaoguang.wang@linux.alibaba.com> <8e597c50-b6f4-ea08-0885-56d5a608a4ca@gmail.com> <9713dc32-8aea-5fd2-8195-45ceedcb74dd@kernel.dk> <82116595-2e57-525b-0619-2d71e874bd88@gmail.com> <148a36f1-ff60-4af6-7683-8849c9973010@kernel.dk> <12c010e5-d298-c48a-1841-ff0da39e2306@kernel.dk> <2a1f4d77-87f4-fe50-b747-8f1be1945b55@linux.alibaba.com> <9e325c66-1b55-6ef9-6fac-cca7b00cda1f@gmail.com> From: Jens Axboe Message-ID: <1f1c9d3d-e4ba-e2dc-c044-2405418bf0cf@kernel.dk> Date: Wed, 18 Nov 2020 08:57:23 -0700 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: <9e325c66-1b55-6ef9-6fac-cca7b00cda1f@gmail.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org On 11/18/20 8:52 AM, Pavel Begunkov wrote: > On 18/11/2020 15:36, Xiaoguang Wang wrote: >>> On 11/18/20 6:59 AM, Pavel Begunkov wrote: >>> Ran it through the polled testing which is core limited, and I didn't >>> see any changes... >> Jens and Pavel, sorry for the noise... > > Not at all, that's great you're trying all means to improve > performance, some are just don't worth the effort. Exactly, never stop trying, it's just that not all efforts pan out. That's pretty typical for software development :-) >> I also have some tests today, in upstream kernel, I also don't see >> any changes, but in our internal 4.19 kernel, I got a steady about 1% >> iops improvement, and > > hmm, 1% is actually a good result It is, I wonder why there's such a big discrepancy between the 4.19 base and current -git in terms of the win on that. Might be changes outside of io_uring. -- Jens Axboe