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 8E0F1C433F5 for ; Thu, 23 Sep 2021 14:39:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 78D0661216 for ; Thu, 23 Sep 2021 14:39:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241778AbhIWOlK (ORCPT ); Thu, 23 Sep 2021 10:41:10 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50410 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241743AbhIWOlG (ORCPT ); Thu, 23 Sep 2021 10:41:06 -0400 Received: from mail-il1-x131.google.com (mail-il1-x131.google.com [IPv6:2607:f8b0:4864:20::131]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 64D34C061757 for ; Thu, 23 Sep 2021 07:39:34 -0700 (PDT) Received: by mail-il1-x131.google.com with SMTP id w1so6906372ilv.1 for ; Thu, 23 Sep 2021 07:39:34 -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=ipddjsuaxiI/286Gm4qQfceIdGUHDBcUdts4yKeCSH4=; b=uHYx8lMBcD3fdcBCoAhrmnl4hqnthU6myTzNsuLBS41zx+AqXblbex40h1gs0amATB ytAxAfRYGJCxEEEZ8nUjC7HLIt/MSp6hWb7eL7ZvBSAsyS+8sdNsc/t/jmDtUM+vkNpF a4s00ie4KO9obs+cSOMmuycxJsi5I9ukm4x0BeZ193Yj/u7k5bXAdaucOC49J6yXR9Vs RV7BB+tM0IITyprJH1F0M4vIhD0CboqhgrfYGnaDMNemQ+tE30lmGrJ4LDyMUVqT69qT M1fiLKBUAbt4LnV7UMFOn//p4SEft0ZcO5NINwbZfiHnCUulSxpPSZtpg/naRBkJL91T kunQ== 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=ipddjsuaxiI/286Gm4qQfceIdGUHDBcUdts4yKeCSH4=; b=emHTcVDjcASiQSS5DEk6kpDCxK+OuFvn413PeBKvoAQZhWAhiVE4Cpu8+KH4nZ8zsU K2a8/n2XIETe36CILqE6efiKhdc5YfUexK55h44e9tiMWGrWei3nh0I+wEJ2DulnATGX y2cdc2uqqjkk9KzL1SljHyIeFlVbOvGKaasvItX3t4jgxT0NozKWi60TyAN4WsAerRF7 GunMnCx+Ah4l11XrENAI1r6EjIn/z/v1SV0bsgr4jZcd1vmedwV8MgYtPi2pnIs6Oydm IIXLKUuy+J8YLnrB4KFcwAtxhXO2TjvbUHmaG/WzntINdJLgiUibleH9Shx0C0q/+7ad Y9fw== X-Gm-Message-State: AOAM5331Dn48vZL1hnH4b+J+PEDU4Am8xWbEYaWm33jptipnxtuNYQJA I1sF0AR4JZZgOLLD5oJMM4LP1A== X-Google-Smtp-Source: ABdhPJzsOYhSeJ2qNXh716/hXIZ2FZll7ocgoOGbyeZS58c5agnlM8KEzaSe+yFSmFDdRInBy5omkQ== X-Received: by 2002:a05:6e02:20e7:: with SMTP id q7mr3930805ilv.309.1632407973711; Thu, 23 Sep 2021 07:39:33 -0700 (PDT) Received: from [192.168.1.30] ([207.135.234.126]) by smtp.gmail.com with ESMTPSA id d12sm2297274iow.16.2021.09.23.07.39.31 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 23 Sep 2021 07:39:32 -0700 (PDT) Subject: Re: [RFC PATCH 00/13] x86 User Interrupts support To: Sohil Mehta , x86@kernel.org Cc: Tony Luck , Dave Hansen , Thomas Gleixner , Ingo Molnar , Borislav Petkov , "H . Peter Anvin" , Andy Lutomirski , Christian Brauner , Peter Zijlstra , Shuah Khan , Arnd Bergmann , Jonathan Corbet , Ashok Raj , Jacob Pan , Gayatri Kammela , Zeng Guang , Dan Williams , Randy E Witt , Ravi V Shankar , Ramesh Thomas , linux-api@vger.kernel.org, linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org References: <20210913200132.3396598-1-sohil.mehta@intel.com> From: Jens Axboe Message-ID: Date: Thu, 23 Sep 2021 08:39:30 -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: <20210913200132.3396598-1-sohil.mehta@intel.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 9/13/21 2:01 PM, Sohil Mehta wrote: > - Discuss potential use cases. > We are starting to look at actual usages and libraries (like libevent[2] and > liburing[3]) that can take advantage of this technology. Unfortunately, we > don't have much to share on this right now. We need some help from the > community to identify usages that can benefit from this. We would like to make > sure the proposed APIs work for the eventual consumers. One use case for liburing/io_uring would be to use it instead of eventfd for notifications. I know some folks do use eventfd right now, though it's not that common. But if we had support for something like this, then you could use it to know when to reap events rather than sleep in the kernel. Or at least to be notified when new events have been posted to the cq ring. -- Jens Axboe