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=-2.2 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,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 06FD3C2D0DB for ; Thu, 23 Jan 2020 19:14:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D680621D7D for ; Thu, 23 Jan 2020 19:14:02 +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="VdZgkZgv" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728904AbgAWTOA (ORCPT ); Thu, 23 Jan 2020 14:14:00 -0500 Received: from mail-pf1-f195.google.com ([209.85.210.195]:40413 "EHLO mail-pf1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728767AbgAWTOA (ORCPT ); Thu, 23 Jan 2020 14:14:00 -0500 Received: by mail-pf1-f195.google.com with SMTP id q8so1977128pfh.7 for ; Thu, 23 Jan 2020 11:14:00 -0800 (PST) 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=+j6n3bLqsywHmHf3IWP7jfMllioYd4CpeP8JoTqsBg4=; b=VdZgkZgvc+axYrbN0WmRyJokY3HmJqCNSto/KBRyWcFp+Pq3NHvPFfpH+sYGzX6Mcf g22nywECZ1Rmo1bhwF+SNdC7agfaEN1xGSqa3LadFG+de8ugL2qYR5ZXfeelocFesZrv /W9uP2k/th0jCtd8sxXpwy8nWxNHNbtVmYtdnTYThMvsagzjZ/1OQ2ZIXj06+UC9ykHA KJgvE5QisCvhHIrX1rGIfwsWHkZQUKPkQEsGQM2e53ibX7zxeacbfPOLc+Dfm9lmuFTR 7au1oO1oKsH0K+ZSQTR5effJiR1/XfGVckuiawtGmcBLc3OjnhUh1UqzMyrgLFaS5mLm 6svw== 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=+j6n3bLqsywHmHf3IWP7jfMllioYd4CpeP8JoTqsBg4=; b=GNFR0lvO+yqbx7a+de2ZB9A/nQSLqyhdV2S78I1W2CSM9fzNZEBvW3ZhhM2m+Zg4S4 c6CEHgrlUhb3/i710M5I8myigNVC0TMB3PKP0CXw97oi6Xx48h4lqcuzL/Zx/iGMXEGL w376IVJQkNmdLmahpIaWWDLbVbOOobDACPAQwt7lrXM1UFcdu+y0muu7UykuMPsyE7C7 rF6u31F2c7SS5Ssh0e7pereUDDZbdh8oIBKb8QCKrUd8ibXawpbvRrAZLKPwyMoURsa+ 4iaEWTsWL4bTudasEbbI84hKL/KucBIXIf5ALlUenuT/veq+9/KuAu41M/YJXN1BnBMu M1Lw== X-Gm-Message-State: APjAAAXyB9Z5klluMsJuHnjQdWhLfBZ2KI0BG/jTWgjGYpzalIVAkosU UQlLwMDFc1dFDkerhsEGU652T8gIGYaANg== X-Google-Smtp-Source: APXvYqyy93D4u/4fyfGaogLMtiMjbjktxYdJjqvu555rM06/JgrUxLKamGaHJUP2hOZTjSK3nw/55A== X-Received: by 2002:a63:500c:: with SMTP id e12mr312091pgb.214.1579806839580; Thu, 23 Jan 2020 11:13:59 -0800 (PST) Received: from ?IPv6:2600:380:4562:fb25:b980:6664:b71f:35b5? ([2600:380:4562:fb25:b980:6664:b71f:35b5]) by smtp.gmail.com with ESMTPSA id k44sm3731287pjb.20.2020.01.23.11.13.58 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 23 Jan 2020 11:13:59 -0800 (PST) Subject: Re: [PATCH] io_uring: wakeup threads waiting for EPOLLOUT events To: Stefano Garzarella Cc: Alexander Viro , io-uring@vger.kernel.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org References: <20200116134946.184711-1-sgarzare@redhat.com> <2d2dda92-3c50-ee62-5ffe-0589d4c8fc0d@kernel.dk> <20200116155557.mwjc7vu33xespiag@steredhat> <5723453a-9326-e954-978e-910b8b495b38@kernel.dk> <20200116162630.6r3xc55kdyyq5tvz@steredhat> <20200116170342.4jvkhbbw4x6z3txn@steredhat> From: Jens Axboe Message-ID: <2d3d4932-8894-6969-4006-25141ca1286e@kernel.dk> Date: Thu, 23 Jan 2020 12:13:57 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.4.1 MIME-Version: 1.0 In-Reply-To: <20200116170342.4jvkhbbw4x6z3txn@steredhat> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On 1/16/20 10:03 AM, Stefano Garzarella wrote: > On Thu, Jan 16, 2020 at 09:30:12AM -0700, Jens Axboe wrote: >> On 1/16/20 9:26 AM, Stefano Garzarella wrote: >>>> Since the use case is mostly single submitter, unless you're doing >>>> something funky or unusual, you're not going to be needing POLLOUT ever. >>> >>> The case that I had in mind was with kernel side polling enabled and >>> a single submitter that can use epoll() to wait free slots in the SQ >>> ring. (I don't have a test, maybe I can write one...) >> >> Right, I think that's the only use case where it makes sense, because >> you have someone else draining the sq side for you. A test case would >> indeed be nice, liburing has a good arsenal of test cases and this would >> be a good addition! > > Sure, I'll send a test to liburing for this case! Gentle ping on the test case :-) -- Jens Axboe