From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nivedita Singhvi Subject: Re: [PATCH] Network Checksum Removal Date: Mon, 23 May 2005 14:12:24 -0700 Message-ID: <42924738.9020106@us.ibm.com> References: <20050520233015.GA26305@us.ibm.com> <8ae78025050523085662a94019@mail.gmail.com> <8ae7802505052309067d88f174@mail.gmail.com> <200505231116.16964.jdmason@us.ibm.com> <8ae7802505052309362c2fb00e@mail.gmail.com> <32fa5a4ad70f86ee5637d30ffc890017@cl.cam.ac.uk> <8ae780250505231255a0cea3b@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <8ae780250505231255a0cea3b@mail.gmail.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: bin.ren@cl.cam.ac.uk Cc: xen-devel@lists.xensource.com, Andrew Theurer , Jon Mason List-Id: xen-devel@lists.xenproject.org Bin Ren wrote: > I've added the support for ethtools. By turning on and off netfront > checksum offloading, I'm getting the following throughput numbers, > using iperf. Each test was run three times. CPU usages are quite > similar in two cases ('top' output). Looks like checksum computation > is not a major overhead in domU networking. > > dom0/1/2 all have 128M memory. dom0 has e1000 tx checksum offloading turned on. Yeah, if you want to do anything network intensive, 128MB is just not enough - you really need more memory in your system. > With Tx checksum on: > > dom1->dom2: 300Mb/s (dom0 cpu maxed out by software interrupts) > dom1->dom0: 459Mb/s (dom0 cpu 80% in SI, dom1 cpu 20% in SI) > dom1->external: 439Mb/s (over 1Gb/s ethernet) (dom0 cpu 50% in SI, > dom1 60% in SI) > > With Tx checksum off: > > dom1->dom2: 301Mb/s > dom1->dom0: 454Mb/s > dom1->externel: 437Mb/s (over 1Gb/s ethernet) iperf is a directional send test, correct? i.e. is dom1 -> dom0 perf the same as dom0 -> dom1 for you? thanks, Nivedita