CentOS - Aug 2011 - vmxnet3 patch for CentOS6 kernel?

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...

<http://patchwork.ozlabs.org/patch/95785/>

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> 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)
Maybe it could go into the plus kernel, but I'm quite sure it will not be
put into the standard kernel.

Did you check if it is in the upcoming 6.1 kernel (2.6.32-131.6.1.el6)?

Simon

On Thu, Aug 11, 2011 at 2:17 PM, Matti Aarnio <matti.aarnio at methics.fi>
wrote:
> Hi,
>
> Could CentOS kernel keepers apply following patch on current kernel?
> ? ?http://patchwork.ozlabs.org/patch/95785/
(snip)
> Could this be applied on stock CentOS kernel so that I could return on
un-customized kernel use?
Because CentOS is a bug-for-bug clone of the upstream vendor's, it is
not possible to modify or apply patches to the distro kernel. But this
could be done in the centosplus kernel.
> PS: bugs.centos.org is apparently unable to send email out, otherwise I
would have written this as a bug report...
Yes, it is broken. I filed a request to repair it at:

http://bugs.centos.org/view.php?id=5032

Akemi

On Fri, 12 Aug 2011 00:17:02 +0300, Matti Aarnio wrote:
> 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.
What is with vmware tools? VMware tools provides the latest vmxnet3 
driver.

The current version is: VMwareTools-8.3.7-433358.tar.gz

Best regards,

Morten