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=-5.5 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 EF9F8C35257 for ; Fri, 2 Oct 2020 16:18:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9D821206FA for ; Fri, 2 Oct 2020 16:18:19 +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="ht42Mv1x" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388004AbgJBQSS (ORCPT ); Fri, 2 Oct 2020 12:18:18 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43108 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726017AbgJBQSS (ORCPT ); Fri, 2 Oct 2020 12:18:18 -0400 Received: from mail-il1-x143.google.com (mail-il1-x143.google.com [IPv6:2607:f8b0:4864:20::143]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 267F8C0613E2 for ; Fri, 2 Oct 2020 09:18:17 -0700 (PDT) Received: by mail-il1-x143.google.com with SMTP id q5so1770262ilj.1 for ; Fri, 02 Oct 2020 09:18:17 -0700 (PDT) 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=eyG5D3V3TaPLgQB2Q8WgTq5oOe5Zz/FFFkte/PznoVM=; b=ht42Mv1xJeYy5NIkco+QvVZEaZmsJjsSCNAuILdVWjsstOU4FQ9kG7/sMx1tA1f4Yu 1lhXMZYO0muMBX1XV52IOKY5FEmBlMm7T7TKlfOvW6B70PKYTWtYf78OiU9gu1LaPW/r dV3Hbckrjh27CNH4AszoG5JyKREritHFpYoSN80Hlr/fVSuXdqLZgvWRr6fyNVROaGhK mKiHKrbaVUXsU470+d54XLQVMwPbOMk8D85UkILFGHjk29ZdxkoaGlC1uVp6UkMT1OhP CyvJ5x/usi+8MLG6dD+lGUjI5DaIzmKS/sspzAJKC3WZVcJ0Q5y/EWtXE8BG6UJqsZYJ kplg== 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=eyG5D3V3TaPLgQB2Q8WgTq5oOe5Zz/FFFkte/PznoVM=; b=Sf6mQewkCFJRL0ucZNFqcToHldLyW7JoQ1qLI+n9sOW4hdJN7hyudmyI0QRRfQfj8r YaEVkWhUAkDS39OLJBTye44lecT+P4cknBcFklzvyyd6xZtX3SINw68EmpEFskPMgmZj yHYX19p7/1DUdI1jYgH4rBodw6mv6hJRnTEqkQVlhyr8DVG/3HXf1U9OSaDpy5uStJwX Znu1/t11QUsByDdG11brte27EwDGS2DpXR6mjl6E7t3d9ME7O2f0Z/FGHtAwSc9u7QwJ nhpWK4ZA82T4stKd263oYeY/YoFyitefnldcYZPOAIq261Zg09MK93cEgqIyBGL33GxB wiBg== X-Gm-Message-State: AOAM531LkYWtNlkHyRqTAoVvj6dz6g5FLRcIIKlJ3DyrSnrvyhbAC+cs 5xaSSbIyKdJ1X2wnXII0QB13yHOV2PdETw== X-Google-Smtp-Source: ABdhPJxD5jsh4jHft20v0ciBnF9lral7z7r2u/FOLHN2GM2hh2A4Wb2HG+1XRHE4xPfEHuh6z6ke5Q== X-Received: by 2002:a92:1bd6:: with SMTP id f83mr625441ill.274.1601655496359; Fri, 02 Oct 2020 09:18:16 -0700 (PDT) Received: from [192.168.1.30] ([65.144.74.34]) by smtp.gmail.com with ESMTPSA id t4sm877765iob.48.2020.10.02.09.18.15 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 02 Oct 2020 09:18:15 -0700 (PDT) Subject: Re: [PATCH 3/3] task_work: use TIF_TASKWORK if available To: Oleg Nesterov , Thomas Gleixner Cc: linux-kernel@vger.kernel.org, io-uring@vger.kernel.org, peterz@infradead.org References: <20201001194208.1153522-1-axboe@kernel.dk> <20201001194208.1153522-4-axboe@kernel.dk> <20201002151415.GA29066@redhat.com> <871rigejb8.fsf@nanos.tec.linutronix.de> <20201002153849.GC29066@redhat.com> From: Jens Axboe Message-ID: <19d2f8cc-320f-a4d1-79e3-fbdef3b44540@kernel.dk> Date: Fri, 2 Oct 2020 10:18:15 -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: <20201002153849.GC29066@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/2/20 9:38 AM, Oleg Nesterov wrote: > On 10/02, Thomas Gleixner wrote: >> >> I think it's fundamentaly wrong that we have several places and several >> flags which handle task_work_run() instead of having exactly one place >> and one flag. > > Damn yes, agreed. As mentioned in the other reply, this is actually a nice step towards NOT having that be the case. Right now we have TWA_RESUME, which uses TIF_NOTIFY_RESUME. Once all archs support TIF_NOTIFY_SIGNAL, then we can totally drop TWA_NOTIFY resume, and use use TWA_SIGNAL as the default for notify == true task_work users. And we can drop task_work noticing and running in the signal handling as well, leaving us with only having tracehook_notify_signal() running the task_work. -- Jens Axboe