On May 24, 2013, at 8:45 AM, Thomas Monjalon <thomas.monjalon at 6wind.com> wrote:
> 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. Yes, the Ixia is sending the standard 64 byte packet. The stats show a send rate of 14.880 Mpps. > > 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. > Yes I am running traffic both ways. Interestingly, the amount of drops seem consistent in both directions. This makes sense since testpmd is spinning off a thread to read from each input queue. > You could also try with 2 ports on 2 different NICs. Hmmm, not sure if I can lay hands on another 82599 card. This one is a loaner. Thanks, Patrick > >>> 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
