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=-5.4 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 4B1E0C432BE for ; Wed, 4 Aug 2021 16:05:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 29615608FC for ; Wed, 4 Aug 2021 16:05:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229812AbhHDQGH (ORCPT ); Wed, 4 Aug 2021 12:06:07 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49522 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229733AbhHDQFy (ORCPT ); Wed, 4 Aug 2021 12:05:54 -0400 Received: from mail-pj1-x1029.google.com (mail-pj1-x1029.google.com [IPv6:2607:f8b0:4864:20::1029]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 22FE0C061799 for ; Wed, 4 Aug 2021 09:05:42 -0700 (PDT) Received: by mail-pj1-x1029.google.com with SMTP id m10-20020a17090a34cab0290176b52c60ddso4215307pjf.4 for ; Wed, 04 Aug 2021 09:05:42 -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=oMkQQfev9jlBqzZwWyEcCECz55KoFmnaUQbMudWMFx8=; b=znhcKD9cKo2ZPI52KWTR8R6vPlHBm/Nqb8u+01DPcGHrOthz7TQH8HvTG6uswxjCGz vJ71fOVnzDD7M5Qn357c1t6/Th2XOpNySKuEnfLi0UsMA3l9MwX3TfXicytYqrU0DU/O HHTkx5X0PxgEqlppbo/I+U42zhae20yT0YTZCRek8uR2grkXTwS/IxTCKoT8LAQSXFoo 2liU1Ty+aVDUFKb60ZGbzWT1tUdv1jZSJXK8m0kz86R7xCLwwGmMsaAZETgr5eMnlGSx yzysUmkOg9L1aD+W+h97pQ3Y0C8QEMEIWUf7JtiELl4ZL7cARdvzwvWWLuuHtAGsdUXu UAQw== 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=oMkQQfev9jlBqzZwWyEcCECz55KoFmnaUQbMudWMFx8=; b=VQ7fyboVvlhUGPINK9Mk+lWuv+/HLun3ndMwDCIXPGM7YDHZgCSia3yjdd8Qjj+z3f Jpc70bLThRD+kjWscpeGbNpwiiyb47Z+E3IAox20toqqsBBvlLM8Ib4u1jHBSFkfvdv8 zZkHOhAUBpkgFs21yeLZWM086ijH/XTTpRbOZXlkW0kNHoWhk78CfSQfq94u0ub/Ls4G 9RED92GjLzl4Q0Re1w1fSITy//qprcTRt2Vv6dRQmyfoBNS6hyS7aD838698dUlUyx8Z DYUlo90+HmDYxvFfK+CHkrxL1mdCmb9hbLpsAsGnmFDzKUriCKgcgo9p/juwXrLeMkvf GTvw== X-Gm-Message-State: AOAM53129fJ0/VRBI71GysQmJceH+q18cZgkV/1NujJZ0MVsb1huFNXU tX0gGEYjA2J5MHKmy6SsAOcNVQ== X-Google-Smtp-Source: ABdhPJwju7zJRV9M9ON3FoQLkg/K2bxj5917bBVgN46rIkWv6Q688Q9h5LyCoCkwZfGRLmsHJLQ1hA== X-Received: by 2002:a63:57:: with SMTP id 84mr221571pga.241.1628093141560; Wed, 04 Aug 2021 09:05:41 -0700 (PDT) Received: from [192.168.1.116] ([198.8.77.61]) by smtp.gmail.com with ESMTPSA id f66sm3607733pfa.21.2021.08.04.09.05.40 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 04 Aug 2021 09:05:41 -0700 (PDT) Subject: Re: [ANNOUNCE] v5.14-rc4-rt4 To: Sebastian Andrzej Siewior Cc: Peter Zijlstra , Daniel Wagner , Thomas Gleixner , LKML , linux-rt-users@vger.kernel.org, Steven Rostedt References: <20210804104340.fhdjwn3hruymu3ml@linutronix.de> <20210804104803.4nwxi74sa2vwiujd@linutronix.de> <20210804110057.chsvt7l5xpw7bo5r@linutronix.de> <20210804131731.GG8057@worktop.programming.kicks-ass.net> <4f549344-1040-c677-6a6a-53e243c5f364@kernel.dk> <20210804153308.oasahcxjmcw7vivo@linutronix.de> <20210804154743.niogqvnladdkfgi2@linutronix.de> <7c946918-ae0d-6195-6a78-b019f9bc1fd3@kernel.dk> <20210804155747.cwayhjsdjc4zaubd@linutronix.de> From: Jens Axboe Message-ID: Date: Wed, 4 Aug 2021 10:05:39 -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: <20210804155747.cwayhjsdjc4zaubd@linutronix.de> 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 8/4/21 9:57 AM, Sebastian Andrzej Siewior wrote: > On 2021-08-04 09:49:48 [-0600], Jens Axboe wrote: >> >> That'd work on non-RT as well, but it makes it worse on non-RT as well with >> the irq enable/disable dance. While that's not the end of the world, would >> be nice to have a solution that doesn't sacrifice anything, yet doesn't >> make RT unhappy. > > There were plans to make local_irq_disable() mostly a nop (similar to > what ppc64 does). But I have no idea what happened. I hope that work > gets picked up. So what do you propose in the interim? As far as io_uring is concerned, it's not a _huge_ deal to do the IRQ dance, but it does bother me that we're making things slightly worse for the mainline kernel just to make the out-of-tree patches happy. -- Jens Axboe