Solarflare
Server
Adapter
User
Guide
Solarflare
Adapters
on
Windows
Issue
20
©
Solarflare
Communications
2017
235
Preferred
NUMA
Node
The
adapter
driver
chooses
a
subset
of
the
available
CPU
cores
to
handle
transmit
and
receive
processing.
The
Preferred
NUMA
Node
setting
can
be
used
to
constrain
the
set
of
CPU
cores
considered
for
processing
to
those
on
the
given
NUMA
Node.
To
force
processing
onto
a
particular
NUMA
Node,
change
the
Preferred
NUMA
Node
setting
on
the
Network
Adapter's
Advanced
Properties
Page.
The
NUMA
distance
of
the
cores
used
for
the
RSS
queue
and
the
network
application
influences
performance.
To
check
the
NUMA
distance
of
each
core
from
the
interface:
•
Get
Coreinfo
from
Windows
Sysinternals
(
).
The
output
includes
processor
to
NUMA
node
mappings.
To
get
the
NUMA
node
local
to
the
interface,
run:
Get
‐
WmiObject
‐
Namespace
root\wmi
‐
Filter
"DummyInstance=False"
EFX_Port
|
Format
‐
Table
‐
AutoSize
Id,Name,PreferredNumaNode
•
On
Windows
Server
2012
and
later,
you
can
instead
run
the
PowerShell
Get
‐
NetAdapterRss
cmdlet
and
look
at
lines
starting:
RssProcessorArray:
[Group:Number/NUMA
Distance]
This
gives
the
NUMA
distance
of
each
core
to
the
interface.
For
low
latency
low
jitter
applications,
RSS
queues
should
be
mapped
to
NUMA
nodes
that
are
local
to
the
interface:
•
On
Windows
Server
2008
R2,
this
should
happen
automatically.
RSS
profiles
are
not
supported,
and
the
default
behavior
is
equivalent
to
ClosestProcessor
•
On
Windows
Server
2012
and
later,
this
should
happen
automatically
if
you
are
using
one
of
the
following
RSS
profiles:
‐
ClosestProcessor
‐
ClosestProcessorStatic
The
PowerShell
Get
‐
NetAdapterRss
cmdlet
will
give
this
information.
The
RSS
Profile
can
be
set
in
the
Network
Adapter's
Advanced
Properties
Page,
or
with
the
PowerShell
cmdlet
Set
‐
NetAdapterRss
•
It
is
also
possible
to
restrict
the
set
of
cores
available
to
RSS
by
setting
BaseProcessorGroup/BaseProcessorNumber
and
MaxProcessorGroup/
MaxProcessorNumber.
•
See
also