Re: [dpdk-dev] [RFC PATCH 0/2] performance utility in testpmd

[Bruce Richardson <bruce.richardson@intel.com>]

On Thu, Apr 21, 2016 at 11:54:12AM +0200, Thomas Monjalon wrote:
> 2016-04-20 18:43, Zhihong Wang:
> > This RFC patch proposes a general purpose forwarding engine in testpmd
> > namely "portfwd", to enable performance analysis and tuning for poll mode
> > drivers in vSwitching scenarios.
> > 
> > 
> > Problem statement
> > -----------------
> > 
> > vSwitching is more I/O bound in a lot of cases since there are a lot of
> > LLC/cross-core memory accesses.
> > 
> > In order to reveal memory/cache behavior in real usage scenarios and enable
> > efficient performance analysis and tuning for vSwitching, DPDK needs a
> > sample application that supports traffic flow close to real deployment,
> > e.g. multi-tenancy, service chaining.
> > 
> > There is a vhost sample application currently to enable simple vSwitching
> > scenarios, it comes with several limitations:
> > 
> >    1) Traffic flow is too simple and not flexible
> > 
> >    2) Switching based on MAC/VLAN only
> > 
> >    3) Not enough performance metrics
> > 
> > 
> > Proposed solution
> > -----------------
> > 
> > The testpmd sample application is a good choice, it's a powerful poll mode
> > driver management framework hosts various forwarding engine.
> 
> Not sure it is a good choice.
> The goal of testpmd is to test every PMD features.
> How far can we go in adding some stack processing while keeping it
> easily maintainable?

I was thinking the exact same thing. Would it not be better to enhance the
existing vhost example application to remove the limitations you call out above?
I don't particularly like the idea of introducing protocol awareness into testpmd
for IP forwarding, for instance.

	Regards,
	/Bruce