Solarflare Solarflare XtremeScale series, User Manual, Page: 89 / 400

Solarflare Server Adapter User Guide
Solarflare Adapters on Linux
Issue 20 © Solarflare Communications 2017 82
Add the following line to
/etc/modprobe.conf file
or add the options line to a
user created file under the
/etc/modprobe.d
directory. The file should have a
.conf
extension
:
options sfc rss_cpus=<option>
To set
rss_cpus
equal to the number of CPU cores:
options sfc rss_cpus=cores
Sometimes, it can be desirable to disable RSS when running single stream
applications, since all interface processing may benefit from taking place on a single
CPU:
options sfc rss_cpus=1
The driver must be reloaded to enable option changes:
NOTE: The association of RSS receive queues to a CPU is governed by the receive
queue's MSI ‐ X interrupt affinity. See Interrupt Affinity on page 113 for more details.
rmmod sfc

modprobe sfc
NOTE: RSS also works for UDP packets. For UDP traffic the Solarflare adapter will
select the Receive CPU based on IP source and destination addresses. Solarflare
adapters support IPv4 and IPv6 RSS.
cores An RSS queue will be created
for each CPU. The first
hyperthread instance (If CPU
has hyperthreading) will be
chosen.
The default option.
A separate MSI ‐ X interrupt for
a receive queue, is affinitized
to each of the CPUs.
hyperthreads An RSS queue will be created
for each CPU hyperthread
(hyperthreading must be
enabled).
A separate MSI ‐ X interrupt for
a receive queue, is affinitized
to each of the hyperthreads.
Table 17: rss_cpus Options
Option Description Interrupt Affinity (MSI ‐ X)