From mboxrd@z Thu Jan 1 00:00:00 1970 From: Zhi Yong Wu Subject: Re: [RFC PATCH net-next 0/3] virtio_net: add aRFS support Date: Thu, 16 Jan 2014 16:48:43 +0800 Message-ID: References: <1389795654-28381-1-git-send-email-zwu.kernel@gmail.com> <52D75EA5.1050000@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Cc: Linux Netdev List , Tom Herbert , Eric Dumazet , "David S. Miller" , Zhi Yong Wu , Stefan Hajnoczi , "Michael S. Tsirkin" , Rusty Russell To: Jason Wang Return-path: Received: from mail-ob0-f181.google.com ([209.85.214.181]:57632 "EHLO mail-ob0-f181.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751037AbaAPIsp (ORCPT ); Thu, 16 Jan 2014 03:48:45 -0500 Received: by mail-ob0-f181.google.com with SMTP id uy5so2373018obc.26 for ; Thu, 16 Jan 2014 00:48:45 -0800 (PST) In-Reply-To: <52D75EA5.1050000@redhat.com> Sender: netdev-owner@vger.kernel.org List-ID: On Thu, Jan 16, 2014 at 12:23 PM, Jason Wang wrote: > On 01/15/2014 10:20 PM, Zhi Yong Wu wrote: >> >> From: Zhi Yong Wu >> >> HI, folks >> >> The patchset is trying to integrate aRFS support to virtio_net. In this >> case, >> aRFS will be used to select the RX queue. To make sure that it's going >> ahead >> in the correct direction, although it is still one RFC and isn't tested, >> it's >> post out ASAP. Any comment are appreciated, thanks. >> >> If anyone is interested in playing with it, you can get this patchset from >> my >> dev git on github: >> git://github.com/wuzhy/kernel.git virtnet_rfs >> >> Zhi Yong Wu (3): >> virtio_pci: Introduce one new config api vp_get_vq_irq() >> virtio_net: Introduce one dummy function virtnet_filter_rfs() >> virtio-net: Add accelerated RFS support >> >> drivers/net/virtio_net.c | 67 >> ++++++++++++++++++++++++++++++++++++++++- >> drivers/virtio/virtio_pci.c | 11 +++++++ >> include/linux/virtio_config.h | 12 +++++++ >> 3 files changed, 89 insertions(+), 1 deletions(-) >> > > Please run get_maintainter.pl before sending the patch. You'd better at > least cc virtio maintainer/list for this. Is this one must for virtio stuff? > > The core aRFS method is a noop in this RFC which make this series no much > sense to discuss. You should at least mention the big picture here in the > cover letter. I suggest you should post a RFC which can run and has expected > result or you can just raise a thread for the design discussion. Yes, it currently miss some important stuff as i said in another mail of this series. > > And this method has been discussed before, you can search "[net-next RFC > PATCH 5/5] virtio-net: flow director support" in netdev archive for a very > old prototype implemented by me. It can work and looks like most of this RFC > have already done there. ah? Can you let me know the result of your discussion? Will checked it, thanks for your pointer. > > A basic question is whether or not we need this, not all the mq cards use > aRFS (see ixgbe ATR). And whether or not it can bring extra overheads? For > virtio, we want to reduce the vmexits as much as possible but this aRFS Good question, i also have concern about this, and don't know if Tom has good explanation. > seems introduce a lot of more of this. Making a complex interfaces just for > an virtual device may not be good, simple method may works for most of the > cases. > > We really should consider to offload this to real nic. VMDq and L2 > forwarding offload may help in this case. By the way, Stefan, can you let us know your concerns here? as we talked in irc channel. :) -- Regards, Zhi Yong Wu