User`s guide

Chapter V. WD-UDP

[root@r10 ~]# /usr/local/src/hpcbench/udp/udpserver -p 9000 &

[1] 11453

[root@r10 ~]# TCP socket listening on port [9000]

[root@r10 ~]# LD_PRELOAD=libcxgb4_sock.so

/usr/local/src/hpcbench/udp/udpserver -p 9001 &

[2] 11454

[root@r10 ~]# TCP socket listening on port [9001]

[root@r10 ~]#

Then on r9, we run udptest to port 9000 to see the host stack UDP latency:

[root@r9 ~]# /usr/local/src/hpcbench/udp/udptest -r 5 -a -h 192.168.1.112 -p

9000

Running the same test with libcxgb4_sock:

[root@r9 ~]# LD_PRELOAD=libcxgb4_sock.so /usr/local/src/hpcbench/udp/udptest

-r 5 -a -h 192.168.1.112 -p 9001

4.1.5. Performance tuning on 2.6.18 kernel

To get better performance with WD-UDP using the 2.6.18 kernel, load the iw_cxgb4 modules

with the ocqp_support=0 parameter. For example,

modprobe iw_cxgb4 ocqp_support=0

4.1.6. Determining if the application is being offloaded

To see if the application is being offloaded, open a window on one of the machines, and run

tcpdump against the Chelsio interface. If you see minimal UDP output on the interface, then the

UDP traffic is being properly offloaded.