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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4C8AAC04A95 for ; Wed, 28 Sep 2022 19:31:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234251AbiI1Tbn (ORCPT ); Wed, 28 Sep 2022 15:31:43 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33170 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233913AbiI1Tbk (ORCPT ); Wed, 28 Sep 2022 15:31:40 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6DA788A1DF; Wed, 28 Sep 2022 12:31:39 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 0AD5461F8E; Wed, 28 Sep 2022 19:31:39 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 014AEC433D6; Wed, 28 Sep 2022 19:31:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1664393498; bh=hdeDfn+4pOe+cjXoOHjt47jgTjJlielsJd73t5oAtfA=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=gEDpm3l8olKcZrpGrz+Gxg/Pceyk6OtW1tIPK7C6LDOWYxyzs6+JmnJl6vThyVcfO dvbtJUrT1gcl3ikauRhekHxOCMQVS/7wHY5GNi9Y82ucKNS6/VOJTNocrh+em7Q2WA ZFL8/IZWeK3JSvSKhJE5bJKps+RZ5LjRKCGA3qqlYAmdkUKDFgLWHr8Kca3FGuJFAq cQEN4cuuO5tVi3+cLDQ+0DXXYJ7BKT0dRTwoM6k4lJypq+Q+Xdlxud9ZVr9g/Tj35Y 6Q8QG6D4nVT6johW9zqG+WG8dJfZm9BjkgnsJGyYO/hYdsP309ScTe3827B3D3lkrS jl4DdD5V6LRKg== Message-ID: <3cccec37-ef58-cccb-7ab8-499ebfe133be@kernel.org> Date: Wed, 28 Sep 2022 13:31:37 -0600 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:91.0) Gecko/20100101 Thunderbird/91.13.0 Subject: Re: [PATCH net-next v4 00/27] io_uring zerocopy send Content-Language: en-US To: Pavel Begunkov , io-uring@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Cc: "David S . Miller" , Jakub Kicinski , Jonathan Lemon , Willem de Bruijn , Jens Axboe , kernel-team@fb.com References: <2c49d634-bd8a-5a7f-0f66-65dba22bae0d@kernel.org> <0f54508f-e819-e367-84c2-7aa0d7767097@gmail.com> <812c3233-1b64-8a0d-f820-26b98ff6642d@kernel.org> <3b81b3e1-2810-5125-f4a0-d6ba45c1fbd3@kernel.org> <24b050e0-433f-dc97-7aab-15c9175f49fa@gmail.com> From: David Ahern In-Reply-To: <24b050e0-433f-dc97-7aab-15c9175f49fa@gmail.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 9/26/22 1:08 PM, Pavel Begunkov wrote: > Tried it out, the branch below fixes a small problem, adds a couple > of extra optimisations and now it actually uses registered buffers. > >     https://github.com/isilence/iperf iou-sendzc thanks for the patch; will it pull it in. > > Still, the submission loop looked a bit weird, i.e. it submits I/O > to io_uring only when it exhausts sqes instead of sending right > away with some notion of QD and/or sending in batches. The approach > is good for batching (SQ size =16 here), but not so for latency. > > I also see some CPU cycles being burnt in select(2). io_uring wait > would be more natural and perhaps more performant, but I didn't > spend enough time with iperf to say for sure. ok. It will be a while before I have time to come back to it. In the meantime it seems like some io_uring changes happened between your dev branch and what was merged into liburing (compile worked on your branch but fails with upstream). Is the ZC support in liburing now?