Sunay Tripathi wrote: > Fischer, Anna wrote: >>> As far as limiting the bandwidth used by a particular >>> ethernet port overall, if you want that level of control, >>> then you probably need to use Crossbow soft rings instead of >>> hardware rings. I don't see any other solution. But most >>> people only want to use resource control to divvy up the >>> bandwidth between different VMs or processes, and would like >>> to use the maximum bandwidth to the box if possible. So PCI >>> IOV is useful there. >> Can you give a rough estimate about how much performance impact it has to >> use Crossbow soft rings instead of hardware rings (when using bandwidth >> limiting)? >> > > It depends on lot of things like size of packets etc but > our current measurements with iperf etc show that S/W > classification and soft rings cause 4-5% performance > regression compared to using Rx rings and H/W classification. > >>> Btw, there are other solutions besides PCI IOV. Any NIC >>> which has multiple rings and separate rx/tx interrupts can >>> have the same feature with Crossbow. The nxge hardware is an >>> example of this. I believe the Intel Zoar NIC is also >>> multiple-ring capable, though I believe that the driver that >>> just got integrated does not have support it yet. >> Have you had a look at the Intel VMDq feature, too? Is this something that >> Crossbow can benefit from? > > VMDq is just like Rx rings from what I understand and I think > it fits into Crossbow framework without much change needed. Right, current Crossbow framework can handle Intel's VMDq fairly well. You may want to refer to the crossbow design document for Hardware Resources Management. Ring grouping feature is the interface for VMDq.
Thanks, Roamer -- # telnet (650)-786-6759 (x86759) Connected to Solaris.Sun.COM. login: Lu, Yunsong Last login: January 2, 2007 from beyond.sfbay Yunsong.Lu at Sun.COM v1.03 Since Mon Dec. 22, 2003 [Roamer at Solaris Networking]# cd ..
