From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: Re: [RFC 0/2] Delayed binding of UDP sockets for Quic per-connection sockets Date: Sun, 4 Nov 2018 10:58:43 -0800 Message-ID: References: <20181031232635.33750-1-cpaasch@apple.com> <20181101221118.GG1685@MacBook-Pro-19.local> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Cc: Christoph Paasch , willemdebruijn.kernel@gmail.com, netdev@vger.kernel.org, lhedstrom@apple.com To: Jana Iyengar , Ian Swett Return-path: Received: from mail-pg1-f196.google.com ([209.85.215.196]:32833 "EHLO mail-pg1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728835AbeKEEOp (ORCPT ); Sun, 4 Nov 2018 23:14:45 -0500 Received: by mail-pg1-f196.google.com with SMTP id q5-v6so3185518pgv.0 for ; Sun, 04 Nov 2018 10:58:45 -0800 (PST) In-Reply-To: Content-Language: en-US Sender: netdev-owner@vger.kernel.org List-ID: On 11/04/2018 02:45 AM, Jana Iyengar wrote: > I think SO_TXTIME solves the most egregious problem I have with using sched_fq for QUIC. That's a great help, so thank you! > > That said, as Ian says, SO_TXTIME does not allow for the flow isolation properties of sched_fq, which would be a nice secondary benefit. I suspect that can also be done in a similar manner to SO_TXTIME -- by attaching an opaque label to each sendmsg which is used by sched_fq to determine the flow. Is that feasible? The plan is to have flow isolation, without having to change applications to provide a flow identifier, since we can not trust user applications anyway. FQ will perform a proper flow dissection for packets sent over unconnected UDP sockets. FQ has two parts [1], one being used by locally generated packets (local TCP stack), one being used in forwarding workloads. The patch which I will send shortly (when net-next reopens) will only make sure FQ does not use skb->sk as a flow identifier if the socket is not a connected one. [1] See commit 06eb395fa9856b5a87cf7d80baee2a0ed3cdb9d7 for some details.