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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D94FDC6FD19 for ; Mon, 13 Mar 2023 14:17:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231204AbjCMORL (ORCPT ); Mon, 13 Mar 2023 10:17:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47940 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230424AbjCMORF (ORCPT ); Mon, 13 Mar 2023 10:17:05 -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 C44CF5C9C8 for ; Mon, 13 Mar 2023 07:16:53 -0700 (PDT) Received: by mail-il1-x133.google.com with SMTP id y12so2795042ilq.4 for ; Mon, 13 Mar 2023 07:16:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20210112.gappssmtp.com; s=20210112; t=1678717013; h=content-transfer-encoding:in-reply-to:from:references:cc:to :content-language:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=XNEL4l0swnCTQCDn63hdWZ9w/KZETPh/ZiDh0JjJWl4=; b=dujQrmUscRtPXqCMzGkLrUJflRptzP3oZ4l9Jy9IFEpstO+QcbjbTR1kTWKoMYQmOL fkDdUxWSvBpQ34Hy+PYuiRZIQg6R2KjV9EpJynnZWO3D1rJcJA7s1hRpS+J6aF78lAoZ XVTmHIPZXdWI6hIVdCSQBo6qHgDItcpVugi3IoMpy3aMnSQbehS3soa0bgxRjT+oFSPj s1O3tks45MbPI2KMJgjkqF7rREolk9iY3ZFYUj9bSf8ixVl4qamWZ0s2Ru9OEt/ltF3i wfEI/yWSn++lUrMKBpQtXQYYxUz0TIcYk6efoCex95f7Tg6LIZ1VRynR00CJrw0l2L6W lduQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1678717013; h=content-transfer-encoding:in-reply-to:from:references:cc:to :content-language:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=XNEL4l0swnCTQCDn63hdWZ9w/KZETPh/ZiDh0JjJWl4=; b=vqql1NmxXCSjY8iIAA8PtSI8og6g8/adgvcS+xHBnOLweBpeOhU99hjwxfbQh2ZV1y YXKSy2tGveEiqpuzEkode4LBbehYVIsYOO0xppt0z/D/tPTanhAKtHlc4x7tkcQD1eD3 91kndltQvAh+quHEYRToyFn6q2PnFmWREQFH7R/BzYhFHQGh+7ilX0yokWb0/kuUjSt7 seSGOS+WWMUxNsBBCtdSw+rZtAigD/MCKLU1Ezz/+eQ8yp3kTYC1HJ/Qir3FjfwpKkdZ Rs1hv8XGLPw52MYQVVCbUvbLOcIaDFPzhkAbwtPUZZw1gyoC7OgEW5rLBoJ9YS2azURx FN7Q== X-Gm-Message-State: AO0yUKW28+hMvJ12cB2jo1kSlP+JzlUeU+TbsmJ9yHRqLwuvPBEeUy1x yX+WXn+bzshZb2exY9Lf2EQIdA== X-Google-Smtp-Source: AK7set9OkGE0IqOxTpWpX3T6cDY1p5xgwzk9FvMsrJTtaOFh25r+LM3UfsbnfS3L6sKZb6XO6FdNSA== X-Received: by 2002:a92:d186:0:b0:323:504:cff6 with SMTP id z6-20020a92d186000000b003230504cff6mr2137669ilz.3.1678717013026; Mon, 13 Mar 2023 07:16:53 -0700 (PDT) Received: from [192.168.1.94] ([96.43.243.2]) by smtp.gmail.com with ESMTPSA id b21-20020a029a15000000b003f1929b34f2sm2515143jal.68.2023.03.13.07.16.52 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 13 Mar 2023 07:16:52 -0700 (PDT) Message-ID: Date: Mon, 13 Mar 2023 08:16:51 -0600 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux aarch64; rv:102.0) Gecko/20100101 Thunderbird/102.8.0 Subject: Re: [RFC 0/2] optimise local-tw task resheduling Content-Language: en-US To: Pavel Begunkov , io-uring@vger.kernel.org Cc: linux-kernel@vger.kernel.org References: <9250606d-4998-96f6-aeaf-a5904d7027e3@kernel.dk> <9322c9ab-6bf5-b717-9f25-f5e55954db7b@kernel.dk> <4ed9ee1e-db0f-b164-4558-f3afa279dd4f@gmail.com> From: Jens Axboe In-Reply-To: <4ed9ee1e-db0f-b164-4558-f3afa279dd4f@gmail.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 3/12/23 9:45?PM, Pavel Begunkov wrote: >>>> Didn't take a closer look just yet, but I grok the concept. One >>>> immediate thing I'd want to change is the FACILE part of it. Let's call >>>> it something a bit more straightforward, perhaps LIGHT? Or LIGHTWEIGHT? >>> >>> I don't really care, will change, but let me also ask why? >>> They're more or less synonyms, though facile is much less >>> popular. Is that your reasoning? >> >> Yep, it's not very common and the name should be self-explanatory >> immediately for most people. > > That's exactly the problem. Someone will think that it's > like normal tw but "better" and blindly apply it. Same happened > before with priority tw lists. But the way to fix that is not through obscure naming, it's through better and more frequent review. Naming is hard, but naming should be basically self-explanatory in terms of why it differs from not setting that flag. LIGHTWEIGHT and friends isn't great either, maybe it should just be explicit in that this task_work just posts a CQE and hence it's pointless to wake the task to run it unless it'll then meet the criteria of having that task exit its wait loop as it now has enough CQEs available. IO_UF_TWQ_CQE_POST or something like that. Then if it at some point gets modified to also encompass different types of task_work that should not cause wakes, then it can change again. Just tossing suggestions out there... -- Jens Axboe