Hi,
Could CentOS kernel keepers apply following patch on current kernel? http://patchwork.ozlabs.org/patch/95785/
(Current as: 2.6.32-71.29.1.el6.x86_64)
With the patch applied, and a ".local" kernel built, I get 30% higher throughput with vmxnet3 in my IP routing node, than when using e1000 "card" at the same. Without the patch, the TCP flow over vmxnet3 driver on a _router_ node is abysmally slow.
I am running a bunch of CentOS servers on VMware ESXi 4.1U1 hosts with multiple of VLANs. The best network performance is obtainable with vmxnet3 network driver in normal case. This driver includes so called LRO optimization, which boosts TCP flow network performance on end-nodes, but kills it on routers, thus the LRO mode needs to be disabled on a host doing routing in between network interfaces.
The issue is a bug in vmxnet3 driver, which is not able to disable LRO mode when the kernel is telling the driver to do so. The patch for it applies on 2.6.32 kernels as well as 2.6.38/39 where it got applied to baseline.
Could this be applied on stock CentOS kernel so that I could return on un-customized kernel use?
Best Regards, Matti Aarnio
PS: bugs.centos.org is apparently unable to send email out, otherwise I would have written this as a bug report...