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 1FD7DC433EF for ; Fri, 17 Jun 2022 16:43:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1383394AbiFQQnC (ORCPT ); Fri, 17 Jun 2022 12:43:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52830 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1383393AbiFQQnB (ORCPT ); Fri, 17 Jun 2022 12:43:01 -0400 Received: from smtp-relay-internal-0.canonical.com (smtp-relay-internal-0.canonical.com [185.125.188.122]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EDC7812AEC for ; Fri, 17 Jun 2022 09:42:59 -0700 (PDT) Received: from mail-pj1-f71.google.com (mail-pj1-f71.google.com [209.85.216.71]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by smtp-relay-internal-0.canonical.com (Postfix) with ESMTPS id 62D1D3FC12 for ; Fri, 17 Jun 2022 16:42:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=canonical.com; s=20210705; t=1655484178; bh=w2QkeXu0zMTbME5HaSJXMRmAa5SiQhl01ubZT4gunvE=; h=From:To:cc:Subject:In-reply-to:References:MIME-Version: Content-Type:Date:Message-ID; b=Q197zgh+FnU6xGWSt5CtuATe4V+p2xpsy3tYLklO+IqKQNDxZdWvoqinoqPWjjgZE ceYaZjFXxg4j19THZk2GRZCq4amKWZeZOxGXUD6LL4AiCmZsUpVai3Pp0UCmz8YVSR +Tk8EsfUe7StNpDwuOSiWMHFNXm8Q12HDnt0adqUTdUmtdfWtxD9jVXRSpTzn+DugF bt7EkTAq1EEI7UHGePzuGdulRelELtD1cwK/fnerFmWtIp6O9tsXZ5bMlJXz4EnP4J 4x1bj71dbnS7o4s6PfPWB4Jwk+1zNrLcXvNIMzkfZbCQQiHV7ZZ743ebXSBEz2T8Qo MNxBVCH+4eKdg== Received: by mail-pj1-f71.google.com with SMTP id u9-20020a17090a2b8900b001ec79a1050eso1080104pjd.4 for ; Fri, 17 Jun 2022 09:42:58 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:in-reply-to:references :comments:mime-version:content-id:date:message-id; bh=w2QkeXu0zMTbME5HaSJXMRmAa5SiQhl01ubZT4gunvE=; b=xsIgiG8c7LdB+flWmTu2DvvqM2SaEoObPi0LYdbpoDkt8HrMcKKHseQZ0DlsdW+Z7v pLJeRDpLKTzEsV12sP4JpEg5ZCpfEY85Xl0qRcAzyPUXzEbDfh5Nd1ASnQOmK3e6yw0W 2ELvT9GiitrzBVXAc9BVWhKbqNW5erAwsX0Z68R8A58q2ln5560pnZA9M6bvjLUNAdtf 4Co9rSTeGzwTe4faX7HR9rurclKJOjMjQ/eUlQmxfloW92fYfszQkRbozPAdYSPrMH/k BnK42JKFfHqlv54Qk1aQH4hfqHRMHdUAnwcnV8mo9j1jYDoBw3yTDByCjhoGLB7oXOho pZHg== X-Gm-Message-State: AJIora/hVFQfxHSHyaxqMn9JjNA7aFdFAi8uDxBS6MG3tDITF58/yrX3 JL2qtUtJXS/yFgjP+AFOokvg5RDmvpmn5AiHVsUjyY2HdmW2NRVVyozFnJJn2pq9Lx0HqtU+eEO Edi2r0o8YBygFfpjDzI8I+OFKJPkxPN/Vkw== X-Received: by 2002:a05:6a00:ad2:b0:4f1:2734:a3d9 with SMTP id c18-20020a056a000ad200b004f12734a3d9mr10966018pfl.61.1655484177017; Fri, 17 Jun 2022 09:42:57 -0700 (PDT) X-Google-Smtp-Source: AGRyM1vmDbgjjOfQxy2wwhMOfWvpGiIye1Npw7UNvXIfo68Txi12ei841SqUXWzTSo7nd78i2CSzTA== X-Received: by 2002:a05:6a00:ad2:b0:4f1:2734:a3d9 with SMTP id c18-20020a056a000ad200b004f12734a3d9mr10965989pfl.61.1655484176717; Fri, 17 Jun 2022 09:42:56 -0700 (PDT) Received: from famine.localdomain ([50.125.80.157]) by smtp.gmail.com with ESMTPSA id g17-20020a639f11000000b004085adf1372sm3915323pge.77.2022.06.17.09.42.56 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Fri, 17 Jun 2022 09:42:56 -0700 (PDT) Received: by famine.localdomain (Postfix, from userid 1000) id A6E856093D; Fri, 17 Jun 2022 09:42:55 -0700 (PDT) Received: from famine (localhost [127.0.0.1]) by famine.localdomain (Postfix) with ESMTP id A0DB5A0B36; Fri, 17 Jun 2022 09:42:55 -0700 (PDT) From: Jay Vosburgh To: Jakub Kicinski cc: "David S. Miller" , Eric Dumazet , Paolo Abeni , netdev@vger.kernel.org, Jonathan Toppins , Veaceslav Falico , Andy Gospodarek Subject: Re: [PATCH net] veth: Add updating of trans_start In-reply-to: <20220617084535.6d687ed0@kernel.org> References: <9088.1655407590@famine> <20220617084535.6d687ed0@kernel.org> Comments: In-reply-to Jakub Kicinski message dated "Fri, 17 Jun 2022 08:45:35 -0700." X-Mailer: MH-E 8.6+git; nmh 1.6; Emacs 29.0.50 MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-ID: <5764.1655484175.1@famine> Date: Fri, 17 Jun 2022 09:42:55 -0700 Message-ID: <5765.1655484175@famine> Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Jakub Kicinski wrote: >On Thu, 16 Jun 2022 12:26:30 -0700 Jay Vosburgh wrote: >> Since commit 21a75f0915dd ("bonding: Fix ARP monitor validation"), >> the bonding ARP / ND link monitors depend on the trans_start time to >> determine link availability. NETIF_F_LLTX drivers must update trans_start >> directly, which veth does not do. This prevents use of the ARP or ND link >> monitors with veth interfaces in a bond. > >Why is a SW device required to update its trans_start? trans_start is >for the Tx hang watchdog, AFAIK, not a general use attribute. There's >plenty of NETIF_F_LLTX devices, are they all broken? In this case, it's to permit the bonding ARP / ND monitor to function if that software device (veth in this case) is added to a bond using the ARP / ND monitor (which relies on trans_start, and has done so since at least 2.6.0). I'll agree it's a niche case; this was broken for veth for quite some time, but veth + netns is handy for software only test cases, so it seems worth doing. I didn't exhaustively check all LLTX drivers, but, e.g., tun does update trans_start: drivers/net/tun.c: /* NETIF_F_LLTX requires to do our own update of trans_start */ queue = netdev_get_tx_queue(dev, txq); txq_trans_cond_update(queue); -J --- -Jay Vosburgh, jay.vosburgh@canonical.com