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=-5.8 required=3.0 tests=BAYES_00,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 CD916C432BE for ; Tue, 27 Jul 2021 22:41:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AD18560F6D for ; Tue, 27 Jul 2021 22:41:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232272AbhG0WlR (ORCPT ); Tue, 27 Jul 2021 18:41:17 -0400 Received: from vps0.lunn.ch ([185.16.172.187]:48734 "EHLO vps0.lunn.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232336AbhG0WlP (ORCPT ); Tue, 27 Jul 2021 18:41:15 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lunn.ch; s=20171124; h=In-Reply-To:Content-Disposition:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:From:Sender:Reply-To:Subject: Date:Message-ID:To:Cc:MIME-Version:Content-Type:Content-Transfer-Encoding: Content-ID:Content-Description:Content-Disposition:In-Reply-To:References; bh=pmcqorDtNtoD1g0ufe4Uy6O//KZkJ4mkvGlwp8H6qmc=; b=a7GbZNXpXwi2yZ6GNzX5yM+bX2 SIE2L8vR3kJDTO2xUad3wLZMXQOwFFHPKgCsIBRWHS8lTmQOcnFGOD8sW12X1YebHS94hwihdmdbZ qE4f0SJ38dA2WT2adbX78YXuv4DyqGu5wcHjkq3BRuGz/Q9/zNKVGzRx2kouAtHDb45c=; Received: from andrew by vps0.lunn.ch with local (Exim 4.94.2) (envelope-from ) id 1m8Vl5-00F5hR-4C; Wed, 28 Jul 2021 00:41:07 +0200 Date: Wed, 28 Jul 2021 00:41:07 +0200 From: Andrew Lunn To: Gerhard Engleder Cc: David Miller , Jakub Kicinski , netdev , devicetree@vger.kernel.org Subject: Re: [PATCH net-next 4/5] tsnep: Add TSN endpoint Ethernet MAC driver Message-ID: References: <20210726194603.14671-1-gerhard@engleder-embedded.com> <20210726194603.14671-5-gerhard@engleder-embedded.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org > I also expect some discussion about this feature. Mapping device specific > TX/RX queues to user space is not done in mainline Linux so far. That is probably not quite true. I expect GPUs do it, or at least something very similar. > I will follow your suggestion and drop tsnep_stream.c for the moment. > Any early comments about this feature are welcome, because the direct > use of additional TX/RX queues for real-time communication is the main > feature of this device. I know enough to know i don't know enough about cache management from user space to be able to make any sensible recommendations. You probably want to start a discussion with the XDP people and get them to agree XDP does not work for your use case. Also, the people who implemented zero-copy, MSG_ZEROCOPY and make sure that is also unsuitable. Then see if you can reuse some GPU code which has been well reviewed and tested. You will get less pushback that way, compared to your own code which will need a good review by somebody who understands all the issues. Andrew