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 44096C433DF for ; Thu, 13 Aug 2020 20:33:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F22F020791 for ; Thu, 13 Aug 2020 20:33:55 +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="w6qIwf5y" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726486AbgHMUdz (ORCPT ); Thu, 13 Aug 2020 16:33:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42118 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726312AbgHMUdy (ORCPT ); Thu, 13 Aug 2020 16:33:54 -0400 Received: from mail-io1-xd2b.google.com (mail-io1-xd2b.google.com [IPv6:2607:f8b0:4864:20::d2b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 93091C061757 for ; Thu, 13 Aug 2020 13:33:54 -0700 (PDT) Received: by mail-io1-xd2b.google.com with SMTP id g19so8681679ioh.8 for ; Thu, 13 Aug 2020 13:33:54 -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=WCkp29LLbiFh6rDfQGLlXEj9GkSe3Gs7HQPIT6WIhDw=; b=w6qIwf5yrqOcYeqRklbULVnZXrdabpJkZR89hz8JO2f+2eAAl38UTd5/ZYDTSnuq5S 3YThxmdfwlPs6n/OH3cV6Xd7dqoUu7vJ9cUJmoDP2VsxqoT8DQs+6vEEXYpZqNiTbWuA 5GuQszCk1melq9XNVlmrc4v/dollJdUAb6lQc+njzYID+ApFlOe2+0bQWGD2rCeQX4We n7s9FUEewiUhwVguR4Aop0hxcD3PSMMbTn+sOEhXssXTrRLWU4Jgm+FhC8fMFS2ABi0E KO+LC677mMbQdAniZPqshCLuMCs8WBGlH4gEre+k8OvRG6O9uQG+q4OT9NtCMSih3zFW 3W8g== 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=WCkp29LLbiFh6rDfQGLlXEj9GkSe3Gs7HQPIT6WIhDw=; b=MWe9oJFolAedCJADJrUlW5WCxfs+JDTlgFrJq0vsKcKh5dbGVnsYVdLA8r8yw8CI82 QVEUxyDGUT+Q8NA3dKW8SXGTY+qwFd8K81xdx0PwUEweJEfdmFaS4+rmSbI34/VkbDhK RmGc6G/fZIz+BlklbfCLAVE8hfp5vWrCYD6N7nstYxqAR2CGn/t3BkYQe1r2yTlSfRlb t0PsJZhBECbW5gI41+btAgPAg0uOydxHouYaqQhv52bsLoTZhcxNx8I6hn+qNIfB/0DE p0tiqGEPK/zh0Xa/A7tiENJ7WtxO7+GDnS8FTVz4Qexn6JvCL3dfWmnpbs4nhAw0ulz3 4/GA== X-Gm-Message-State: AOAM533zrto43F6vYdBzO7km4nt2zzhIEWlzGTxWeFp1h+ckoNNs2KPw Ru/7s+vpHlMQ1FSWOOqGnSobyQ== X-Google-Smtp-Source: ABdhPJwNPqBN53gpmpJLPguJcVPGsvLQIuq3uUNxfDwWNumfzrqeF4Dc/QX+B0Lk7Tr6mYXXlxIVIQ== X-Received: by 2002:a05:6602:14c1:: with SMTP id b1mr6357694iow.163.1597350833439; Thu, 13 Aug 2020 13:33:53 -0700 (PDT) Received: from [192.168.1.58] ([65.144.74.34]) by smtp.gmail.com with ESMTPSA id t14sm3114936ios.18.2020.08.13.13.33.52 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 13 Aug 2020 13:33:53 -0700 (PDT) Subject: Re: [PATCHSET 0/2] io_uring: handle short reads internally To: Jeff Moyer Cc: io-uring@vger.kernel.org, david@fromorbit.com References: <20200813175605.993571-1-axboe@kernel.dk> From: Jens Axboe Message-ID: <99c39782-6523-ae04-3d48-230f40bc5d05@kernel.dk> Date: Thu, 13 Aug 2020 14:33:52 -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: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: io-uring-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org On 8/13/20 2:25 PM, Jeff Moyer wrote: > Jens Axboe writes: > >> Since we've had a few cases of applications not dealing with this >> appopriately, I believe the safest course of action is to ensure that >> we don't return short reads when we really don't have to. >> >> The first patch is just a prep patch that retains iov_iter state over >> retries, while the second one actually enables just doing retries if >> we get a short read back. > > Have you run this through the liburing regression tests? > > Tests failed > > I'll take a look at the failures, but wanted to bring it to your > attention sooner rather than later. I was using your io_uring-5.9 > branch. The eed8b54e0df-test failure is known with this one, pretty sure it was always racy, but I'm looking into it. The timeout-overflow test needs fixing, it's just an ordering thing with the batched completions done through submit. Not new with these patches. The read-write one I'm interested in, what did you run it on? And what was the failure? -- Jens Axboe