From mboxrd@z Thu Jan 1 00:00:00 1970 From: John Fastabend Subject: Re: [net-next PATCH v2 0/5] XDP adjust head support for virtio Date: Wed, 8 Feb 2017 08:39:13 -0800 Message-ID: <589B49B1.4070304@gmail.com> References: <20170203031251.23054.25387.stgit@john-Precision-Tower-5810> <20170207053455-mutt-send-email-mst@kernel.org> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Cc: kubakici@wp.pl, jasowang@redhat.com, ast@fb.com, john.r.fastabend@intel.com, netdev@vger.kernel.org To: "Michael S. Tsirkin" Return-path: Received: from mail-pg0-f65.google.com ([74.125.83.65]:35532 "EHLO mail-pg0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752035AbdBHQlB (ORCPT ); Wed, 8 Feb 2017 11:41:01 -0500 Received: by mail-pg0-f65.google.com with SMTP id 204so15612340pge.2 for ; Wed, 08 Feb 2017 08:39:27 -0800 (PST) In-Reply-To: <20170207053455-mutt-send-email-mst@kernel.org> Sender: netdev-owner@vger.kernel.org List-ID: [...] > However, I came up with a new idea for the future and I'd like to show > where I'm going. The idea is that we don't use s/g buffers on RX, so we > have a pointer per descriptor untapped. So we can allow users to stick > their own pointer in there, if they promise not to use s/g on this vq. > With a full extra pointer to play with, we can go wild. I looked at this quickly it seems like it would work and allow us to avoid the reset. However, it seems like a lot of churn to avoid a single reset. I don't see the reset itself as being that bad of an operation. I agree the reset is not ideal though. Are there any other use cases for this other than XDP? > > Take a look but it doesn't even build yet. > Need to roll it out to all devices etc. > > ---> > [...]