From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jesper Dangaard Brouer Subject: Re: [PATCH RFC 4/9] veth: Use NAPI for XDP Date: Tue, 1 May 2018 10:43:06 +0200 Message-ID: <20180501104306.33c65bd8@redhat.com> References: <20180424143923.26519-1-toshiaki.makita1@gmail.com> <20180424143923.26519-5-toshiaki.makita1@gmail.com> <20180501095008.207c354f@brouer.com> <79ff8b87-2ee2-ce60-36f3-6f3f79cb3272@lab.ntt.co.jp> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: Toshiaki Makita , netdev@vger.kernel.org, brouer@redhat.com To: Toshiaki Makita Return-path: Received: from mx3-rdu2.redhat.com ([66.187.233.73]:40114 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753155AbeEAInL (ORCPT ); Tue, 1 May 2018 04:43:11 -0400 In-Reply-To: <79ff8b87-2ee2-ce60-36f3-6f3f79cb3272@lab.ntt.co.jp> Sender: netdev-owner@vger.kernel.org List-ID: On Tue, 1 May 2018 17:02:34 +0900 Toshiaki Makita wrote: > On 2018/05/01 16:50, Jesper Dangaard Brouer wrote: > > On Tue, 24 Apr 2018 23:39:18 +0900 > > Toshiaki Makita wrote: > > > >> +static int veth_xdp_enqueue(struct veth_priv *priv, void *ptr) > >> +{ > >> + if (unlikely(ptr_ring_produce(&priv->xdp_ring, ptr))) > >> + return -ENOSPC; > >> + > >> + return 0; > >> +} > > > > Here we have a lock per (enqueued) packet. I'm working on changing the > > ndo_xdp_xmit API to allow bulking. And the tun driver have exact same > > issue/need. > > Probably I should have noted in commitlog, but this per-packet lock is > removed in patch 9. > I'm curious about if any change is needed by your new API. Again, I'm just moving this into the generic code, to avoid having to implement this for every driver. Plus, with CONFIG_RETPOLINE we have the advantage of only calling ndo_xdp_xmit once (indirect function pointer call). -- Best regards, Jesper Dangaard Brouer MSc.CS, Principal Kernel Engineer at Red Hat LinkedIn: http://www.linkedin.com/in/brouer