On Thu, 28 Jun 2012 09:00:34 -0700 Greg Rose <[email protected]> wrote:
> On Thu, 28 Jun 2012 09:03:51 +0000 > "Waskiewicz Jr, Peter P" <[email protected]> wrote: > > > On Thu, 2012-06-28 at 08:55 +0000, Anna Fischer wrote: > > > Hi, I have 2 VCPUs assigned to the VM. I thought more CPUs > > > wouldn't really help because a single TCP connection doesn't span > > > across cores anyway? I would have to run multiple connections > > > simultaneously I think. > > > > Do you see 2 Tx and 2 Rx queues in ethtool -S ethX inside your VM or > > no? The issue you can run into is head-of-line blocking of ACKs > > being sent if you're using a single Tx and Rx queue. TCP > > connections can't have their ACKs sent or be received and processed > > since there's pending data packets needing to be serviced. > > > > -PJ > > The currently released ixgbevf driver uses only a single tx/rx queue > pair. The VF has access to two queues but there is no way to direct > traffic to multiple queues in the VF anyway, since it does not support > RSS, DCB or any other way of directing traffic across multiple receive > queues. > > Still, the numbers that you are seeing are a bit low. Generally we > see closer to 6.5 Gbps on a single VF but there are other factors that > could come into play to affect that number I suppose. I take that back, I just ran a netperf TCP_MAERTS test that got over 8Gbps on a single VF. Anyway, it is certainly possible to get higher rates than 5.5Gbps. - Greg ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ _______________________________________________ E1000-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/e1000-devel To learn more about Intel® Ethernet, visit http://communities.intel.com/community/wired
