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=-6.0 required=3.0 tests=BAYES_00,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 A384DC433E1 for ; Mon, 22 Mar 2021 16:42:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 62778619AE for ; Mon, 22 Mar 2021 16:42:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229890AbhCVQly (ORCPT ); Mon, 22 Mar 2021 12:41:54 -0400 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:49125 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230231AbhCVQlg (ORCPT ); Mon, 22 Mar 2021 12:41:36 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1616431295; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=WJs/8i/2hkoGdB658bHnbrqVNm/IrfHamj6wRjahfew=; b=RNwQ8BqaSxV/AP1cn09E7o34KOboRI9rMUEV/HZJ9pubWvWHs2c5iF3kqCgp7f2sKLqv0Q e07wIs2yyZO0VcWSiN8LqoI+5FS5u8YZ41ImbNc3S7JuSW0YHZH7A4udrtjAjcgdN4XkmQ i1QKia71j6sx28fk8f659LPkYzSsvsk= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-442-wJ7d-O2dMIe37-v8OfdiSQ-1; Mon, 22 Mar 2021 12:41:31 -0400 X-MC-Unique: wJ7d-O2dMIe37-v8OfdiSQ-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 0902B81622; Mon, 22 Mar 2021 16:41:30 +0000 (UTC) Received: from ovpn-115-44.ams2.redhat.com (ovpn-115-44.ams2.redhat.com [10.36.115.44]) by smtp.corp.redhat.com (Postfix) with ESMTP id 5470617D7E; Mon, 22 Mar 2021 16:41:28 +0000 (UTC) Message-ID: Subject: Re: [PATCH net-next 2/8] udp: skip fwd/list GRO for tunnel packets From: Paolo Abeni To: Willem de Bruijn Cc: Network Development , "David S. Miller" , Jakub Kicinski , Steffen Klassert , Alexander Lobakin Date: Mon, 22 Mar 2021 17:41:27 +0100 In-Reply-To: References: <661b8bc7571c4619226fad9a00ca49352f43de45.1616345643.git.pabeni@redhat.com> Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.36.5 (3.36.5-2.fc32) MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Mon, 2021-03-22 at 09:24 -0400, Willem de Bruijn wrote: > On Sun, Mar 21, 2021 at 1:01 PM Paolo Abeni wrote: > > If UDP GRO forwarding (or list) is enabled, > > Please explicitly mention the gso type SKB_GSO_FRAGLIST. I, at least, > didn't immediately grasp that gro forwarding is an alias for that. I see the commit message was not clear at all, I'm sorry. The above means: gso_type & (NETIF_F_GSO_UDP_L4 | NETIF_F_GSO_FRAGLIST) :) > > and there are > > udp tunnel available in the system, we could end-up doing L4 > > aggregation for packets targeting the UDP tunnel. > > Is this specific to UDP tunnels, or can this also occur with others, > such as GRE? (not implying that this patchset needs to address those > at the same time) I did not look at that before your suggestion. Thanks for pointing out. I think the problem is specific to UDP: when processing the outer UDP header that is potentially eligible for both NETIF_F_GSO_UDP_L4 and gro_receive aggregation and that is the root cause of the problem addressed here. > > Just skip the fwd GRO if this packet could land in an UDP > > tunnel. > > Could you make more clear that this does not skip UDP GRO, only > switches from fraglist-based to pure SKB_GSO_UDP_L4. Sure, I'll try to rewrite the commit message. Thanks! Paolo