From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael S. Tsirkin" Subject: Re: [Questions] Date: Wed, 20 Aug 2014 12:05:20 +0200 Message-ID: <20140820100520.GA16698@redhat.com> References: <53F46C3D.1030106@huawei.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Jason Wang , netdev@vger.kernel.org, davem@davemloft.net, kvm@vger.kernel.org, liuyongan@huawei.com, qinchuanyu@huawei.com To: "Zhangjie (HZ)" Return-path: Content-Disposition: inline In-Reply-To: <53F46C3D.1030106@huawei.com> Sender: netdev-owner@vger.kernel.org List-Id: kvm.vger.kernel.org On Wed, Aug 20, 2014 at 05:37:01PM +0800, Zhangjie (HZ) wrote: > Hi MST, > > I see "reduce networking latency" > from Networking Todo, the idea is to "allow handling short packets from softirq or VCPU context". > If from softirq context, how could softirq copy skb to guest memory? If the method is to use mmstruct of Qemu, > would it be expensive? I have some very rough patches to explain this part of the idea. Will dig them out for you. > If from VCPU context, maybe the internal operation of the virtual machine will have a significant delay. We'd have to find a good heuristic here. Maybe for a small number of very short packets the delay won't be significant. > Thanks! > -- > Best Wishes! > Zhang Jie