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=-2.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 07247C43331 for ; Mon, 11 Nov 2019 14:37:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CFDA421925 for ; Mon, 11 Nov 2019 14:37:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1573483055; bh=wt2SP0Q7YpLCVKnumwcbslHQuGSL73MTys1RYn9Q7yA=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=0BJNWv/UvNUg+bcwQlFQ8panXklNWK9G//OG9blXMkX6LYhTom0lMB7D96wfsOPfw 7MtN/IBT1cQfgg6CmUSz0O5T1lD+UOfwJkkdq1TjGPYamLCLPu5olEggOEDZ7snJLp CuoY22wO8BAv3UeHfgfYmhZWinoprXX+oO2yBq3g= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726976AbfKKOhf (ORCPT ); Mon, 11 Nov 2019 09:37:35 -0500 Received: from mail.kernel.org ([198.145.29.99]:43148 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726832AbfKKOhe (ORCPT ); Mon, 11 Nov 2019 09:37:34 -0500 Received: from localhost.localdomain (unknown [77.139.212.74]) (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 BA70121925; Mon, 11 Nov 2019 14:37:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1573483053; bh=wt2SP0Q7YpLCVKnumwcbslHQuGSL73MTys1RYn9Q7yA=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=j3Cnu/Lr+GY5ByGjbfJNXHl3blG1p0sR/Zv8TSCZXqDTTOO49tpNoMjoug4Or1BdF jo4CR9OfNfbFqyWXAm/fltYXC5Y9AaBpm2EgVeeI8lRPzbk6LWwn7FaICcQ+kUrivL KjkjfopEOZ8zxE+DE62hbrmKH7VXbewGpFNA3RHc= Date: Mon, 11 Nov 2019 16:37:25 +0200 From: Lorenzo Bianconi To: Andrew Lunn Cc: ilias.apalodimas@linaro.org, brouer@redhat.com, netdev Subject: Re: Regression in mvneta with XDP patches Message-ID: <20191111143725.GB4197@localhost.localdomain> References: <20191111134615.GA8153@lunn.ch> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="mvpLiMfbWzRoNl4x" Content-Disposition: inline In-Reply-To: <20191111134615.GA8153@lunn.ch> User-Agent: Mutt/1.12.1 (2019-06-15) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org --mvpLiMfbWzRoNl4x Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable > Hi Lorenzo, Jesper, Ilias >=20 Hi Andrew, > I just found that the XDP patches to mvneta have caused a regression. >=20 > This one breaks networking: >=20 > commit 8dc9a0888f4c8e27b25e48ff1b4bc2b3a845cc2d (HEAD) > Author: Lorenzo Bianconi > Date: Sat Oct 19 10:13:23 2019 +0200 >=20 > net: mvneta: rely on build_skb in mvneta_rx_swbm poll routine > =20 > Refactor mvneta_rx_swbm code introducing mvneta_swbm_rx_frame and > mvneta_swbm_add_rx_fragment routines. Rely on build_skb in oreder to > allocate skb since the previous patch introduced buffer recycling usi= ng > the page_pool API. > This patch fixes even an issue in the original driver where dma buffe= rs > are accessed before dma sync. > mvneta driver can run on not cache coherent devices so it is > necessary to sync DMA buffers before sending them to the device > in order to avoid memory corruptions. Running perf analysis we can > see a performance cost associated with this DMA-sync (anyway it is > already there in the original driver code). In follow up patches we > will add more logic to reduce DMA-sync as much as possible. >=20 > I'm using an Linksys WRT1900ac, which has an Armada XP SoC. Device > tree is arch/arm/boot/dts/armada-xp-linksys-mamba.dts. looking at the dts, could you please confirm mvneta is using hw or sw buffe= r manager on this board? Moreover are you using DSA as well? Regards, Lorenzo >=20 > With this patch applied, transmit appears to work O.K. My dhcp server > is seeing good looking BOOTP requests and replying. However what is > being received by the WRT1900ac is bad. >=20 > 11:36:20.038558 d8:f7:00:00:00:00 (oui Unknown) > 00:00:00:00:5a:45 (oui = Ethernet) Null Informati4 > 0x0000: 0000 0000 0000 0000 0000 0000 0000 0000 ................ > 0x0010: 0000 0000 0000 0000 0000 0000 0000 0000 ................ > 0x0020: 0000 0000 0000 0000 0000 0000 0000 0000 ................ > 0x0030: 0000 0000 0000 ...... > 11:36:26.924914 d8:f7:00:00:00:00 (oui Unknown) > 00:00:00:00:5a:45 (oui = Ethernet) Null Informati4 > 0x0000: 0000 0000 0000 0000 0000 0000 0000 0000 ................ > 0x0010: 0000 0000 0000 0000 0000 0000 0000 0000 ................ > 0x0020: 0000 0000 0000 0000 0000 0000 0000 0000 ................ > 0x0030: 0000 0000 0000 ...... > 11:36:27.636597 4c:69:6e:75:78:20 (oui Unknown) > 6e:20:47:4e:55:2f (oui = Unknown), ethertype Unkn=20 > 0x0000: 2873 7472 6574 6368 2920 4c69 6e75 7820 (stretch).Linux. > 0x0010: 352e 342e 302d 7263 362d 3031 3438 312d 5.4.0-rc6-01481- > 0x0020: 6739 3264 3965 3038 3439 3662 382d 6469 g92d9e08496b8-di > 0x0030: 7274 7920 2333 2053 756e 204e 6f76 2031 rty.#3.Sun.Nov.1 > 0x0040: 3020 3136 3a31 373a 3531 2043 5354 2032 0.16:17:51.CST.2 > 0x0050: 3031 3920 6172 6d76 376c 0e04 009c 0080 019.armv7l...... > 0x0060: 100c 0501 0a00 000e 0200 0000 0200 1018 ................ > 0x0070: 1102 fe80 0000 0000 0000 eefa aaff fe01 ................ > 0x0080: 12fe 0200 0000 0200 0804 6574 6830 fe09 ..........eth0.. > 0x0090: 0012 0f03 0100 0000 00fe 0900 120f 0103 ................ > 0x00a0: ec00 0010 0000 e3ed 5509 0000 0000 0000 ........U....... > 0x00b0: 0000 0000 0000 0000 0000 0000 0000 0000 ................ > 0x00c0: 0000 0000 0000 0000 0000 0000 0000 0000 ................ > 0x00d0: 0000 0000 0000 0000 0000 0000 0000 0000 ................ > 0x00e0: 0000 0000 0000 >=20 > This actually looks like random kernel memory. >=20 > Andrew --mvpLiMfbWzRoNl4x Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iHUEABYIAB0WIQTquNwa3Txd3rGGn7Y6cBh0uS2trAUCXclyIgAKCRA6cBh0uS2t rDpEAQD4pZz+sgn4HFLyKWSzwkEo0CWcBEB9dTUMXyjr7piPXQEAgASHPediNrB1 WHfdbfhPsEB4jcHjM6IUcBB1Cljemw8= =LGoR -----END PGP SIGNATURE----- --mvpLiMfbWzRoNl4x--