From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8F21C4400; Mon, 11 Aug 2025 00:03:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1754870595; cv=none; b=GG391+gTEVveP0gIivd5gS8+TF+M8JP7bPB3RcvokjeMalwszIinT9csCr9NlFiRGJcRmEJfPuOvbeKWiMQXYa0NDCqzHfJZrO5VSxjeQVKGGFK11AlxSzQkqhm61+gN+GnsLB5bMgSHNPfd7VIWi/PS8RVC2ax5H1kPbhfICWI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1754870595; c=relaxed/simple; bh=X+BdXFqquj9DQr6IZy+gnd+atvFm1saLgYgTBYGsDcc=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=RSPldG5gKe5AkcM7Rl9q4AOcKcQBOMU5mwrwcodKm2UO3Sw9Cz8GMy2oIzOItSBmoKnZKjRoP7cB9Fv5XpX9pTG5SOxlvpXD1rv8SgD7rci3bErjzddWfcpt8vuBiZROf3oEAfzutwdk6QpPANEuJnS517e5DgUpQmEqSPJCpLY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=IwNhIrTS; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="IwNhIrTS" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6B93CC4CEEB; Mon, 11 Aug 2025 00:03:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1754870594; bh=X+BdXFqquj9DQr6IZy+gnd+atvFm1saLgYgTBYGsDcc=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=IwNhIrTSncJxWdZ2aY0n/OpWBzLHtdeDdtqD5+L1CFL86UORnALYCcQp0lr46IJmK QfYpITQOe/3jNfCUoktAuooa3UV0HRXYiD5QT9oe/awIBZjKB1Iha+ntxvt0S8zcUv +5jNoWOfLSKqHgr9ElMOr3navaHtvZCm+yEZYLHaeETo99A2vnX3O1jN5EUlAUzfaK zS/tjGE1uUJRXVuEHgXYMIHi5GVWwHBtVLEpqEnCPb4pAPocc1MrIUHLxfK6R3PdO8 Xn9tjuhyZKJCWL3ouaL1S9d4CsrXUm7B3KNegfsW7sl0SHwx/h3Plfvge1bDvhceJG 9dYQaxn6JaY5w== Message-ID: <8358d907-0edc-4ff0-a520-9cec3c84a49a@kernel.org> Date: Sun, 10 Aug 2025 18:03:12 -0600 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH net-next v2] net: vrf: don't down the interface when add slave Content-Language: en-US To: Ido Schimmel , Menglong Dong Cc: andrew+netdev@lunn.ch, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, horms@kernel.org, sdf@fomichev.me, kuniyu@google.com, ahmed.zaki@intel.com, aleksander.lobakin@intel.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org References: <20250807055634.113753-1-dongml2@chinatelecom.cn> From: David Ahern In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 8/10/25 1:41 AM, Ido Schimmel wrote: > On Thu, Aug 07, 2025 at 01:56:34PM +0800, Menglong Dong wrote: >> For now, cycle_netdev() will be called to flush the neighbor cache when >> add slave by downing and upping the slave netdev. When the slave has >> vlan devices, the data transmission can interrupted. > > OK, but can you provide more details on the production use case for > enslaving the real device to a VRF during runtime? Usually this kind of > configuration is performed before data transmission begins. I suspect > this is why nobody complained about this behavior despite being present > in the VRF driver since its initial submission almost a decade ago. > > I'm asking because the potential for regressions from this patch seems > quite high to me. For example, before this patch nexthop objects using > the enslaved device would get flushed, but now they persist. This can > impact offload of nexthop objects and it's possible I'm missing more > potential regressions. > +1 Thanks for staying on top of this, Ido. I have been very distracted the past few months. The design choices when the VRF code was first written was either 1) require the devices to be added to a VRF while down, or 2) cycle the device while adding it to the VRF. I preferred 2 as the simplest choice for users, and so that is the way the feature went in.