○
improve peak throughput.
• Decreasing the interrupt moderation interval will:
○
generate more interrupts
○
increase CPU utilization (because there are more interrupts to process)
○
decrease latency
○
reduce peak throughput.
• Turning off interrupt moderation will:
○
generate the most interrupts
○
give the highest CPU utilization
○
give the lowest latency
○
give the biggest reduction in peak throughput.
For many transaction request-response type network applications, the benefit of reduced latency
to overall application performance can be considerable. Such benefits typically outweigh the cost
of increased CPU utilization. It is recommended that:
• Interrupt moderation is disabled for applications that require best latency and jitter
performance, such as market data handling.
• Interrupt moderation is enabled for high throughput single (or few) connection TCP streaming
applications, such as iSCSI.
Interrupt moderation can be changed using ethtool, where
<interface>
is the interface name.
Before adjusting the interrupt moderation interval, it is recommended to disable adaptive
moderation:
ethtool -C <interface> adaptive-rx off
To set the RX interrupt moderation
interval
in microseconds (μs):
ethtool –C <interface> rx-usecs <interval>
To turn off interrupt moderation, set an interval of zero (0):
ethtool –C <interface> rx-usecs 0
To set the TX interrupt moderation interval:
ethtool –C <interface> tx-usecs <interval>
Chapter 5: Tuning
UG1523 (v1.0) October 18, 2022
Alveo X3522 User Guide
37
