Chelsio Communications Terminator 6, Инструкция по установке и эксплуатации, Страница: 64 / 432

Chapter II. Network (NIC/TOE)
Chelsio Unified Wire for Linux 64
[root@host~]# t4_perftune.sh
Discovering Chelsio T4/T5 devices ...
Configuring Chelsio T4/T5 devices ...
Tuning eth7
IRQ table length 4
Writing 1 in /proc/irq/62/smp_affinity
Writing 2 in /proc/irq/63/smp_affinity
Writing 4 in /proc/irq/64/smp_affinity
Writing 8 in /proc/irq/65/smp_affinity
eth7 now up and tuned
...
Because there are 4 CPUs on the system, 4 entries of interrupts are assigned. For other network
interfaces, you should see similar output message.
Now the receiving tra
ffic is dynamically assigned to one of the system’s CPUs through a
Terminator queue. This achieves a balanced usage among all the processors. This can be
verified, for example, by using the
iperf tool. First set up a server on the receiver host:
[root@receiver_host~]# iperf – s
Then on the sender host, send data to the server using the iperf client mode. To emulate a
moderate traffic workload, use
-P option to request 20 TCP streams from the server:
[root@sender_host~]# iperf -c receiver_host_name_or_IP -P 20
Then on the receiver host, look at interrupt rate at /proc/interrupts :
[root@receiver_host~]# cat /proc/interrupts | grep eth6
Id CPU0 CPU1 CPU2 CPU3 type interface
36: 115229 0 0 1 PCI-MSI-edge eth6 (queue 0)
37: 0 121083 1 0 PCI-MSI-edge eth6 (queue 1)
38: 0 0 105423 1 PCI-MSI-edge eth6 (queue 2)
39: 0 0 0 115724 PCI-MSI-edge eth6 (queue 3)
Now interrupts from eth6 are evenly distributed among the 4 CPUs.
Without Terminator’s RSS support, the interrupts caused by network traffic may be distributed
unevenly over CPUs. For your information, the traffic produced by the same iperf commands