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=-1.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 9B11CC433DF for ; Wed, 20 May 2020 19:12:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 556A3207D4 for ; Wed, 20 May 2020 19:12:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1590001975; bh=RkadoWIBanOCKs885+ED7RmQ3OubhGzfviJ/NcHqSpQ=; h=Date:From:To:Cc:Subject:In-Reply-To:References:List-ID:From; b=x1SgLHRgIrgu4/fTGJinyvWtgSGyn9/TXsS7y+kMn20Bw4uDfcfVe0JICppbkHjxc K/LN+dC4Wf3smDCXrNQucKm+5b0U8g+P3e+ZRCbIHBt6DaIbB37nrymvR9mIEQEChK ozos4aS+Fe/Hay5Rfbgo0gRUocSL3Jw9kJIPh+ho= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726785AbgETTMy (ORCPT ); Wed, 20 May 2020 15:12:54 -0400 Received: from mail.kernel.org ([198.145.29.99]:33856 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726548AbgETTMy (ORCPT ); Wed, 20 May 2020 15:12:54 -0400 Received: from kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com (unknown [163.114.132.4]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id D263E206B6; Wed, 20 May 2020 19:12:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1590001974; bh=RkadoWIBanOCKs885+ED7RmQ3OubhGzfviJ/NcHqSpQ=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=rw5tsy8H36Pu1JKsNiiFQqBkB5Pi/LVWydxf1b3yMRdALCSv6dIW3zZDKsU2GkOZl YKnl/9CvPINgEOxX+KrsSaiqjsC7kjKV8/n8PtTdjnOT3/oZZAZlVCT//TSiq1+U9O ZgWXAwhzaW+rd1AaRHqY43xqOwKyoclx6KuzrZUA= Date: Wed, 20 May 2020 12:12:52 -0700 From: Jakub Kicinski To: Ioana Ciornei Cc: "davem@davemloft.net" , "netdev@vger.kernel.org" Subject: Re: [PATCH v2 net-next 0/7] dpaa2-eth: add support for Rx traffic classes Message-ID: <20200520121252.6cee8674@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> In-Reply-To: References: <20200515184753.15080-1-ioana.ciornei@nxp.com> <20200515124059.33c43d03@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> <20200515152500.158ca070@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> <20200518123540.3245b949@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> <20200519114342.331ff0f1@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> <20200519143525.136d3c3c@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Wed, 20 May 2020 15:10:42 +0000 Ioana Ciornei wrote: > DPAA2 has frame queues per each Rx traffic class and the decision from which queue > to pull frames from is made by the HW based on the queue priority within a channel > (there is one channel per each CPU). IOW you're reading the descriptor for the device memory/iomem address and the HW will return the next descriptor based on configured priority? Presumably strict priority? > If this should be modeled in software, then I assume there should be a NAPI instance > for each traffic class and the stack should know in which order to call the poll() > callbacks so that the priority is respected. Right, something like that. But IMHO not needed if HW can serve the right descriptor upon poll.