Solarflare Solarflare XtremeScale series, User Manual, Page: 119 / 400

Solarflare Server Adapter User Guide
Solarflare Adapters on Linux
Issue 20 © Solarflare Communications 2017 112
Adapters ‐ Software Support
To benefit from recent driver optimizations, the following (minimum) net driver and
firmware versions should be used:
# ethtool ‐ i eth<N>

driver: sfc

version: 4.4.1.1017

firmware ‐ version: 4.4.2.1011 rx1 tx1
For latency sensitive applications, the adapter firmware variant should be set with
the sfboot utility to ultra ‐ low ‐ latency:
# sfboot ‐‐ adapter=eth<N> firmware ‐ variant=ultra ‐ low ‐ latency
The ultra ‐ low ‐ latency firmware variant is being used when the output from ethtool
(above) shows the rx1 and tx1 values.
A reboot of the server is required after changes using sfboot .
rss_numa_local=1 On SMP systems it is recommended to have all
interrupts on the NUMA node local to the Solarflare
adapter: rss_numa ‐ local=1, and pin nginx threads to
the free CPUs even when these are on the non ‐ local
node.
When this is not possible, CPU cores can be divided
equally between interrupts and nginx threads.
rss_numa_local=1 is the default setting.
Pinning threads Application threads and interrupts should not be
pinned to the same CPU cores.
ethtool ‐ C adaptive ‐ rx off Disable the irq ‐ balance service to prevent re ‐
distribution of interrupts by the kernel. Disable
adaptive interrupt moderation before setting the
interrupt moderation interval.
ethtool ‐ C rx ‐ usecs 60 Set the interrupt moderation interval.
When processing smaller packets it is generally
better to set a higher interval i.e. 60µsecs and for
larger packets a lower interval or even zero to disable
interrupt moderation.
See Interrupt Moderation (Interrupt Coalescing) on
page 105 .
Table 23: nginx Server Tuning
Tuning Notes