From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael S. Tsirkin" Subject: Re: 8% performance improved by change tap interact with kernel stack Date: Wed, 29 Jan 2014 09:56:30 +0200 Message-ID: <20140129075630.GC23228@redhat.com> References: <52E766D4.4070901@huawei.com> <20140128083459.GB16833@redhat.com> <52E77506.1080604@huawei.com> <20140128094138.GA17332@redhat.com> <52E78416.50000@huawei.com> <20140128103325.GA17794@redhat.com> <52E8B0A4.6030806@huawei.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: jasowang@redhat.com, Anthony Liguori , KVM list , netdev@vger.kernel.org To: Qin Chuanyu Return-path: Content-Disposition: inline In-Reply-To: <52E8B0A4.6030806@huawei.com> Sender: kvm-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Wed, Jan 29, 2014 at 03:41:24PM +0800, Qin Chuanyu wrote: > On 2014/1/28 18:33, Michael S. Tsirkin wrote: > > >>>Nice. > >>>What about CPU utilization? > >>>It's trivially easy to speed up networking by > >>>burning up a lot of CPU so we must make sure it's > >>>not doing that. > >>>And I think we should see some tests with TCP as well, and > >>>try several message sizes. > >>> > >>> > >>Yes, by burning up more CPU we could get better performance easily. > >>So I have bond vhost thread and interrupt of nic on CPU1 while testing. > >> > >>modified before, the idle of CPU1 is 0%-1% while testing. > >>and after modify, the idle of CPU1 is 2%-3% while testing > >> > >>TCP also could gain from this, but pps is less than UDP, so I think > >>the improvement would be not so obviously. > > > >Still need to test this doesn't regress but overall looks convincing to me. > >Could you send a patch, accompanied by testing results for > >throughput latency and cpu utilization for tcp and udp > >with various message sizes? > > > >Thanks! > > > because of spring festival of china, the test result would be given > two week later. > throughput would be test by netperf, and latency would be tested by > qperf. Is that OK? For testing - sounds good. Run vmstat in host to check host cpu utilization. Pls don't forget to address all issues raised in this thread and in the old one Eric mentioned: http://patchwork.ozlabs.org/patch/52963/ either address in code or address in commit log why it doesn't apply anymore. -- MST