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 7F1BAC433F5 for ; Thu, 25 Nov 2021 16:44:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240501AbhKYQsI (ORCPT ); Thu, 25 Nov 2021 11:48:08 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:32920 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240162AbhKYQqI (ORCPT ); Thu, 25 Nov 2021 11:46:08 -0500 Received: from mail-ed1-x52d.google.com (mail-ed1-x52d.google.com [IPv6:2a00:1450:4864:20::52d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6BFA7C061757 for ; Thu, 25 Nov 2021 08:20:56 -0800 (PST) Received: by mail-ed1-x52d.google.com with SMTP id l25so27534545eda.11 for ; Thu, 25 Nov 2021 08:20:56 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=cNXp8PhPArnuL700uZkm+l1bBClTcmyiGId8YW9sHXY=; b=YcDzK9r/JELN8V7lUZsOYN9vy/+9AOnab2Y022+QU8DtS7jYg5AyQx5vKT1cjJPp9R hv5SCbieGRKKY8CiDxWR81Oy4GtUqjev3FPaxb3mR7YDCYH1zbwJ0bTG/e7k2R6DZqZd K/1EYBpDPWhIC+5KfkSUzxaSnex/TxIUSIxj32OWXSctuiozqh6hdBYEtpyZiAwOzbhR uZ1wvRVeA8qLQubl/E/NXDk0XPgXjb4okqoDI12g1J06cO2f/fqEKoHcb3uMyGL5BhS9 SAbobsWs09+SrhjCdpi7PhLuzrj7rl+F5LJACIF19tMP/Bshipri/fhRaIe0jUpG4c3g y9/w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=cNXp8PhPArnuL700uZkm+l1bBClTcmyiGId8YW9sHXY=; b=KqrX4QnHOUFOP0teaQusKvP09mOimTYfSwdhCzuFIG1fD2kpFNZhiROyMslsFgcM+g LzdnfspN7Ihx3GA1o6zI3QgXFHJRscHMTJOnVGJBhQbz9qu8WyXX36XkAi3juLg637X1 h2oxzKhdX8B+ZFsVqoFET9SSmXVyN/xsB81dqruzh4tBl2+jPncCye628hVeAyoho/WX iI+E0mzUa338YIt2ukWhs79db0gT3jrtxCwID/Wo7SxcDmg7IBt9dnG5sFKqokCR5BVL zQ47U6E1rVDbiIHfnQISEsT+oYElhBHJ3eeI3TVvkol5l7g8aioPU/Af0bz/R0fiwbM1 DjnQ== X-Gm-Message-State: AOAM531V6g38MQd1JYhPpwJDz/D/Uq1bgcyVD3zv3kdzq0fE7DvVyojk ZX6cP535BODkeeKQC1Rb7XECJP6juFk= X-Google-Smtp-Source: ABdhPJzn8UA71RbwdhPsE8aY1+LBe931qHP0SRzUZL0bxkIYklHTB/SICLaPn2iG7kVi38NM/e1K+Q== X-Received: by 2002:a17:907:1c07:: with SMTP id nc7mr31684231ejc.546.1637857254932; Thu, 25 Nov 2021 08:20:54 -0800 (PST) Received: from skbuf ([188.25.163.189]) by smtp.gmail.com with ESMTPSA id m15sm2215823edl.22.2021.11.25.08.20.53 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 25 Nov 2021 08:20:54 -0800 (PST) Date: Thu, 25 Nov 2021 18:20:53 +0200 From: Vladimir Oltean To: Jakub Kicinski Cc: netdev@vger.kernel.org, "David S. Miller" , Claudiu Manoil , Alexandre Belloni , UNGLinuxDriver@microchip.com, Andrew Lunn , Vivien Didelot , Florian Fainelli , Xiaoliang Yang , Vladimir Oltean Subject: Re: [PATCH v2 net-next] net: dsa: felix: enable cut-through forwarding between ports by default Message-ID: <20211125162053.t4ilul6oh6e5hxxh@skbuf> References: <20211123132116.913520-1-olteanv@gmail.com> <20211124183900.7fb192f4@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> <20211125101652.ansuiha5hlwe3ner@skbuf> <20211125072909.23b4e9d0@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20211125072909.23b4e9d0@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Thu, Nov 25, 2021 at 07:29:09AM -0800, Jakub Kicinski wrote: > > > Obviously shooting from the hip here, but I was expecting the cut-thru > > > update to be before the bridge reconfig if port is joining, and after > > > if port is leaving. Do you know what I'm getting at? > > > > Yes, I know what you're getting at. But it's a bit complicated to do, > > given the layering constraints and that cut-through forwarding is an > > optional feature which isn't present on all devices, so I am trying to > > keep its footprint minimal on the ocelot library. > > > > What I can do is I can disable cut-through forwarding for ports that are > > standalone (not in a bridge). I don't have a use case for that anyway: > > the store-and-forward latency is indistinguishable from network stack > > latency. This will guarantee that when a port joins a bridge, it has > > cut-through forwarding disabled. So there are no issues if it happens to > > join a bridge and its link speed is higher than anybody else: there will > > be no packet underruns. > > Hm, to make sure I understand - fixing standalone ports doesn't > necessary address the issue of a slow standalone port joining, right? Yeah, I think I handled it better in v3 than my initial idea here.