Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752178AbdI1FCe (ORCPT ); Thu, 28 Sep 2017 01:02:34 -0400 Received: from mail-qk0-f179.google.com ([209.85.220.179]:44998 "EHLO mail-qk0-f179.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751710AbdI1FCc (ORCPT ); Thu, 28 Sep 2017 01:02:32 -0400 X-Google-Smtp-Source: AOwi7QAyoeuZvrnhQ/8LZ6PiHio43AzpdegxZWenk0xqxmI1oONY7n7Ko87de+vzijblLMAuS23Tlu7J/PJY6i/0sFQ= MIME-Version: 1.0 In-Reply-To: References: <1506500637-13881-1-git-send-email-jasowang@redhat.com> <20170927230042-mutt-send-email-mst@kernel.org> From: Tom Herbert Date: Wed, 27 Sep 2017 22:02:31 -0700 Message-ID: Subject: Re: [PATCH net-next 0/3] support changing steering policies in tuntap To: Willem de Bruijn Cc: "Michael S. Tsirkin" , Jason Wang , Network Development , LKML Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 918 Lines: 19 On Wed, Sep 27, 2017 at 4:25 PM, Willem de Bruijn wrote: >>> In the future, both simple and sophisticated policy like RSS or other guest >>> driven steering policies could be done on top. >> >> IMHO there should be a more practical example before adding all this >> indirection. And it would be nice to understand why this queue selection >> needs to be tun specific. > > I was thinking the same and this reminds me of the various strategies > implemented in packet fanout. tun_cpu_select_queue is analogous to > fanout_demux_cpu though it is tun-specific in that it requires tun->numqueues. > > Fanout accrued various strategies until it gained an eBPF variant. Just > supporting BPF is probably sufficient here, too. +1, in addition to packet fanout, we have SO_REUSEPORT with BPF, RPS, RFS, etc. It would be nice if existing packet steering mechanisms could be leveraged for tun.