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=-0.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS 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 0B409C33CAA for ; Thu, 23 Jan 2020 21:45:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C934520665 for ; Thu, 23 Jan 2020 21:45:41 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="LGYaj3ag" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729083AbgAWVpl (ORCPT ); Thu, 23 Jan 2020 16:45:41 -0500 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:23228 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728928AbgAWVpl (ORCPT ); Thu, 23 Jan 2020 16:45:41 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1579815940; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=u61jrRml7uBsTChqQkvEyIjmfc5MgOu8Mlxfsu5OMjo=; b=LGYaj3ageoOgOQJYg/Wlyy3OIhnOdZumeDj/G8cRfAEWZzQYax/8aBrpah5R2zMyNAyvEZ qCYBMg+MDpse+Np4GbrmyTskgvB1JqaHlMQG/BUIA9AsmNcj1lJZnXIYT7Muu2HzKLrl67 x6gowANcsZJ4FtrJ1Bya6KtZRzdBg10= Received: from mail-wm1-f69.google.com (mail-wm1-f69.google.com [209.85.128.69]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-30-_YDVTxXDN5O9ujss-rXYdQ-1; Thu, 23 Jan 2020 16:45:38 -0500 X-MC-Unique: _YDVTxXDN5O9ujss-rXYdQ-1 Received: by mail-wm1-f69.google.com with SMTP id 18so1719806wmp.0 for ; Thu, 23 Jan 2020 13:45:38 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=u61jrRml7uBsTChqQkvEyIjmfc5MgOu8Mlxfsu5OMjo=; b=N08qrZY2vIy8nAWe5gqzk8gekik76sLI/47YO4htL/pNVs8nr2rTTbIzQl2u+EaG3q 1BvYDqF5jwOFiBrPjCa86f8Vye1n2MZupH5JOyu2cos1iaC8w2ssVymkfKbMIo9DQZ0B FA1SIahHRLm9wsjyRFMBZGACKTD1Wldxypc2hz34Xr7QZd+bAqvs2OBdxv4Le6unS2Z4 g+8VqXhY9xTY3I0/zQnL1htpPpbrumYvcs8KrYVn3368D5R3wbD5P+qzfluhWMCEO593 9byyFQ45sKML60M5CDwtAUepSBYS68jeloxnmT4ekQatGfCkLHHO8iIB1ceAT90kDm++ YhiQ== X-Gm-Message-State: APjAAAV7vW1r2FAvWbZBgVoXv7nbpTg7qkaZ5Ahg28+laqDDDstDkAP2 pczyZ01sp25/9or0kg8E1cHtHgc+t/WrKyolLHPKqQVms17zMIxMGFjWciTkvtetmc+oMFvaPBi sY8mhLfo8Xdj1AbFMTgc= X-Received: by 2002:a5d:4085:: with SMTP id o5mr91674wrp.321.1579815937023; Thu, 23 Jan 2020 13:45:37 -0800 (PST) X-Google-Smtp-Source: APXvYqypvLRV506GGxMfAQP/vrSzj5p5HHA+EMluQu+yI3TOmaSFK8iaFL33miPix2yjG9Oq+XvZzw== X-Received: by 2002:a5d:4085:: with SMTP id o5mr91651wrp.321.1579815936765; Thu, 23 Jan 2020 13:45:36 -0800 (PST) Received: from steredhat ([80.188.125.198]) by smtp.gmail.com with ESMTPSA id y139sm4299842wmd.24.2020.01.23.13.45.35 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 23 Jan 2020 13:45:35 -0800 (PST) Date: Thu, 23 Jan 2020 22:45:33 +0100 From: Stefano Garzarella To: Jens Axboe Cc: Alexander Viro , io-uring@vger.kernel.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: Re: [PATCH] io_uring: wakeup threads waiting for EPOLLOUT events Message-ID: <20200123214533.ikn4olf7k5dfbaq6@steredhat> 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> <2d3d4932-8894-6969-4006-25141ca1286e@kernel.dk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <2d3d4932-8894-6969-4006-25141ca1286e@kernel.dk> Sender: io-uring-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org On Thu, Jan 23, 2020 at 12:13:57PM -0700, Jens Axboe wrote: > 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 :-) > Yes, you are right :-) I was a little busy this week to finish some works before DevConf. I hope to work on the test case these days, so by Monday I hope I have it ;-) Cheers, Stefano