From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael S. Tsirkin" Subject: Re: [net-next PATCH v5 0/6] XDP for virtio_net Date: Thu, 8 Dec 2016 23:16:47 +0200 Message-ID: <20161208231211-mutt-send-email-mst@kernel.org> References: <20161207200139.28121.4811.stgit@john-Precision-Tower-5810> <20161208.141702.1346950420275854265.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: john.fastabend@gmail.com, daniel@iogearbox.net, shm@cumulusnetworks.com, tgraf@suug.ch, alexei.starovoitov@gmail.com, john.r.fastabend@intel.com, netdev@vger.kernel.org, brouer@redhat.com To: David Miller Return-path: Received: from mx1.redhat.com ([209.132.183.28]:44274 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752652AbcLHVQy (ORCPT ); Thu, 8 Dec 2016 16:16:54 -0500 Content-Disposition: inline In-Reply-To: <20161208.141702.1346950420275854265.davem@davemloft.net> Sender: netdev-owner@vger.kernel.org List-ID: On Thu, Dec 08, 2016 at 02:17:02PM -0500, David Miller wrote: > From: John Fastabend > Date: Wed, 07 Dec 2016 12:10:47 -0800 > > > This implements virtio_net for the mergeable buffers and big_packet > > modes. I tested this with vhost_net running on qemu and did not see > > any issues. For testing num_buf > 1 I added a hack to vhost driver > > to only but 100 bytes per buffer. > ... > > So where are we with this? > > I'm not too thrilled with the idea of making XDP_TX optional or > something like that. If someone enables XDP, there is a tradeoff. The issue is inability of XDP TX to share xmit queues with net stack. I'm guessing virtio is not the only card that has a limited number of queues, is it? Is it really so hard to lock the queue and check it's running? Could be optional in case resources are there ... -- MST