From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wm1-f50.google.com (mail-wm1-f50.google.com [209.85.128.50]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4E02F2FB2 for ; Fri, 25 Jun 2021 18:28:30 +0000 (UTC) Received: by mail-wm1-f50.google.com with SMTP id r3so2315424wmq.1 for ; Fri, 25 Jun 2021 11:28:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:from:to:references:message-id:date:user-agent:mime-version :in-reply-to:content-language:content-transfer-encoding; bh=7uZ896GRLtwIx9KU1ax4TYsql4qljUIsXDZtBfMzuiY=; b=XdgHY0rV0qN134TgyteQ8O83ouV28P18JHExO+Tc1gFXOyUQ9bX91wD5EjqaeTJe0w wza7+zJpNBezeEALHzZJskyY/DCIk6pYWxpt06IoNUl71MfNFIw/rBGUoZe1CSGAlsHZ 41nuFQcaEYjYzFbTzChZ4esGJ+ozD9ypZQJJDjxBEFSYhS4zAOp8ixPaBknstwMAwMi8 AwwG5r7s+Yy14j7W8xgDQpT1zJLZBFS/tugqik1/ZKt70PShbZPlzrnWR+kIyDo5glE6 OXpZv7qYhX/fFC/x+evfDMuSRb6p8XzY4uUIcAfjzlsMErky70JFpXBaV8unRZJYIdOt /OVQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:from:to:references:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=7uZ896GRLtwIx9KU1ax4TYsql4qljUIsXDZtBfMzuiY=; b=UG6XtIdrK1p7I0uzxBCmhhtbhPHok1S/geEGlAC3gpj4wsw+9bRGGryQGnUMuCNNyP mDoVmz7VEmzELFf6YJ7ztGysGKqUYOotfn7L0vRbOJLRXux4uICSLh4dg8MHuk/abuX9 +XzrCaUm1APIkVhL5pPX7fCaMVYFj3fLxgj/8kdKuWcW6wSvfPqtM/JpGIY6QBlQC1OZ zOW1Vet6r359yd5+9mT9/IXQGSf+fwPUoVFf833AVMhdg3J5WkUvJiMTKr/eq8Xk1Vvr IAlkey+JMGGuxjYoZOKZE6a2fAkmvrNL5i2jI/fCxGZw1lmCFprqSMn9ZSAccTu7J/qv 3g7Q== X-Gm-Message-State: AOAM531cBEan29tcXGedJkyFDrGfC2JoFrROu90DH6cM1ToQCaAuw0rF sP4ZCEGjdtUSqlUnO1IBpdcESW2wrzo= X-Google-Smtp-Source: ABdhPJwpJE3+7QRVXK46PiA37HaMbZtppbuADOzHKHlLSgi4Ql+t+IprYx9IhbkppaC5oqKQOKWoag== X-Received: by 2002:a7b:c351:: with SMTP id l17mr12252632wmj.120.1624645708755; Fri, 25 Jun 2021 11:28:28 -0700 (PDT) Received: from [192.168.8.197] ([148.252.129.92]) by smtp.gmail.com with ESMTPSA id e8sm6587023wrq.10.2021.06.25.11.28.27 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 25 Jun 2021 11:28:28 -0700 (PDT) Subject: Re: [TECH TOPIC] io_uring: BPF controlled I/O From: Pavel Begunkov To: ksummit@lists.linux.dev References: Message-ID: <66afa1cd-aeb9-1103-87b5-ab27734871d4@gmail.com> Date: Fri, 25 Jun 2021 19:28:14 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 Precedence: bulk X-Mailing-List: ksummit@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit On 6/25/21 7:24 PM, Pavel Begunkov wrote: Please ignore this: My apologies, looks I screwed it and misread instructions. Please ignore this submission. > io_uring is an asynchronous I/O API crafted for efficiency, where one of > the reasons for using shared rings is to reduce context switching. It got > lots of of features since introduction, and pushing it further we want > to give away some of the control over submitting and controlling I/O to > BPF, minimising the number of context switches even more. > > - It should keep the number of system calls to a minimum. > - Help to lower overhead on scheduling user processes to CPUs > when they have not much to do and will go to sleep briefly. > - Be an alternative to submission queue polling for latency > reduction not taking as much CPU time at the same moment. > > We'll go over the current design [1] and decisions, issues and plans, > and hopefully it will engage a discussion and give impetus to curious > minds to try it out and share ideas on how to tailor the API to fit > their use cases. > > [1] https://lore.kernel.org/io-uring/a83f147b-ea9d-e693-a2e9-c6ce16659749@gmail.com/T/#m31d0a2ac6e2213f912a200f5e8d88bd74f81406b > -- Pavel Begunkov