Re: Best example for showing throughput?

[Thomas Monjalon <thomas.monjalon-pdR9zngts4EAvxtiuMwx3w@public.gmane.org>]

Adding other questions about packet generator:

24/05/2013 16:41, Thomas Monjalon :
> 24/05/2013 16:11, Patrick Mahan :
> > Intel Xeon E5-2690 (8 physical, 16 virtual)
> 
> How many CPU sockets have you ?
> 
> > 64 Gbyte DDR3 memory
> > Intel 82599EB-SPF dual port 10GE interface
> > CentOS 6.4 (2.6.32-358.6.1.el6.x86_64)
> > The 82599 is in a 16x PCI-e slot.
> 
> Check the datasheet of your motherboard.
> Are you sure it is wired as a 16x PCI-e ?
> Is it connected to the right NUMA node ?
> 
> > I have it attached to an IXIA box.

Which packet size are you sending with your packet generator ?
In case of 64 byte packets (with Ethernet CRC), (64+20)*8 = 672 bits.
So line rate is 10000/672 = 14.88 Mpps.
This bandwith should be supported by your 82599 NIC.

Are you sending and receiving on the 2 ports at the same time ?
Forwarding in the 2 directions is equivalent to double the bandwidth.
Maybe that 14.88*2 = 29.76 Mpps is too much for your hardware.

You could also try with 2 ports on 2 different NICs.

> > I have been running the app 'testpmd'
> > in iofwd mode with 2K rx/tx descriptors and 512 burst/mbcache.  I have
> > been varying the # of queues and unfortunately, I am not seeing full
> > line rate.
> 
> What is your command line ?
> 
> > I am seeing about 20-24% droppage on the receive side.  It doesn't seem
> > to matter the # of queues.
> 
> If queues are polled by different cores, it should matter.
> 
> > Question 1: Is 'testpmd' the best application for this type of testing? 
> > If not, which program?  Or do I need to roll my own?
> 
> testpmd is the right application for performance benchmark.
> It is also possible to use examples l2fwd/l3fwd but you should keep
> testpmd.
> 
> > Question 2: I have blacklisted the Intel i350 ports on the motherboard
> > and am using ssh to access the platform.  Could this be affecting the
> > test?
> 
> You mean i350 is used for ssh ? It shouldn't significantly affect your
> test.

-- 
Thomas