From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael S. Tsirkin" Subject: Re: [net PATCH v5 1/6] virtio_net: use dev_kfree_skb for small buffer XDP receive Date: Wed, 25 Jan 2017 05:23:47 +0200 Message-ID: <20170125051810-mutt-send-email-mst@kernel.org> References: <20170117221443.20280.62546.stgit@john-Precision-Tower-5810> <20170117221950.20280.39496.stgit@john-Precision-Tower-5810> <20170123230809-mutt-send-email-mst@kernel.org> <20170124.144328.2195698124358175034.davem@davemloft.net> <20170124215412-mutt-send-email-mst@kernel.org> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Cc: David Miller , john.fastabend@gmail.com, john.r.fastabend@intel.com, netdev@vger.kernel.org, alexei.starovoitov@gmail.com, daniel@iogearbox.net To: Jason Wang Return-path: Received: from mx1.redhat.com ([209.132.183.28]:48086 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751150AbdAYDXt (ORCPT ); Tue, 24 Jan 2017 22:23:49 -0500 Content-Disposition: inline In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: On Wed, Jan 25, 2017 at 10:57:12AM +0800, Jason Wang wrote: > > > On 2017年01月25日 04:08, Michael S. Tsirkin wrote: > > On Tue, Jan 24, 2017 at 02:43:28PM -0500, David Miller wrote: > > > From: "Michael S. Tsirkin" > > > Date: Mon, 23 Jan 2017 23:08:35 +0200 > > > > > > > On Tue, Jan 17, 2017 at 02:19:50PM -0800, John Fastabend wrote: > > > > > In the small buffer case during driver unload we currently use > > > > > put_page instead of dev_kfree_skb. Resolve this by adding a check > > > > > for virtnet mode when checking XDP queue type. Also name the > > > > > function so that the code reads correctly to match the additional > > > > > check. > > > > > > > > > > Fixes: bb91accf2733 ("virtio-net: XDP support for small buffers") > > > > > Signed-off-by: John Fastabend > > > > > Acked-by: Jason Wang > > > > Acked-by: Michael S. Tsirkin > > > > > > > > I think we definitely want this one in -net as it's > > > > a bugfix. > > > This whole series is a bug fix, we must have adjust_header XDP > > > support in the virtio_net driver before v4.10 goes out, it is > > > a requires base feature for XDP. > > I have to say device resets outside probe have a huge potential > > to uncover hypervisor bugs. > > Maybe not if it reuses most of current codes? Since we've already used them > in sleep or hibernation? > > Thanks Except almost no one uses sleep or hybernate with VMs. I'm not saying it's a bad idea, just that it needs a lot of testing before release and we won't get enough if we merge at this point. > > I am rather uncomfortable > > doing that after -rc1. > > > > How about a module option to disable it by default? > > We can then ship a partial implementation in 4.10 > > and work on completing it in 4.11. > > To clarify, I'm thinking an option similar to enable_xdp, and have all packets have a 256 byte headroom for 4.10. Consider our options for 4.11. -- MST