Provided by: intel-cmt-cat_4.4.1-1_amd64 
NAME
rtdset - Task CPU affinity and Intel(R) Resource Director Technology/AMD PQoS control tool
SYNOPSIS
rdtset -t <feature=value;...cpu=cpulist>... -c <cpulist> [-I] (-p <pidlist> | [-k] cmd
[<args>...])
rdtset -r <cpulist> -t <feature=value;...cpu=cpulist>... -c <cpulist> [-I] (-p <pidlist> |
[-k] cmd [<args>...])
rdtset -r <cpulist> -c <cpulist> (-p <pidlist> | [-k] cmd [<args>...])
rdtset -r <cpulist> -t <feature=value;...cpu=cpulist>... [-I] -p <pidlist>
rdtset -t <feature=value> -I [-c <cpulist>] (-p <pidlist> | [-k] cmd [<args>...])
DESCRIPTION
For more details on Intel(R) Resource Director Technology see
http://www.intel.com/content/www/us/en/ architecture-and-technology/resource-director-
technology.html
or https://github.com/intel/intel-cmt-cat/wiki
The rdtset tool provides support to set up the CAT (Cache Allocation Technology) and MBA
(Memory Bandwidth Allocation) capabilities for a task and set its CPU affinity. For MBA,
rdtset offers two modes of operation, fixed MBA rate or closed-loop one monitoring local
memory B/W usage and adjust MBA accordingly. For OS interface, it uses MBA CTRL via
libpqos (OS support available in Linux kernel 4.18 or later). For MSRs, the tool adjusts
MBA configuration by itself based on local memory B/W. Intel(R) RDT/AMD PQoS allocation
operations of the utility are done via libpqos library. Class of service 0 (CLOS0) is
assumed as default one. In command mode, rdtset forks and one process executes the
command. Another process waits for the task to terminate and restores default allocation
state by assigning cpu's back to CLOS0. This behavior is not in place in PID mode.
OPTIONS
rdtset options are as follow:
-h, --help
Show help
-v, --verbose
Verbose mode
-I, --iface-os
Set the library to use the kernel implementation. If not set the default
implementation is to detect the interface automatically (MSR or kernel).
-F <interface>, --iface <interface>
Set the library interface to automatically detected one ('auto'), MSR ('msr') or
kernel interface ('os').
<interface> can be set to either 'auto' (default), 'msr' or 'os'.
If automatic detection is selected ('auto'), it:
1) Takes RDT_IFACE environment variable into account if this variable is set
2) Selects OS interface if the kernel interface is supported
3) Selects MSR interface otherwise
-t --rdt feature=value;...cpu=cpulist
Specify Intel(R) RDT configuration, single class configuration per -t, multiple -t
options allowed.
Accepted values for features:
2, l2 for level 2 cache
3, l3 for level 3 cache
m, mba for MBA
b, mba_max for max allowable local memory bandwidth
For example:
-t 'l3=0xf;cpu=1'
CPU 1 uses four L3 cache-ways (mask 0xf)
-t 'l3=0xf;cpu=2' -t 'l3=0xf0;cpu=3,4,5'
CPU 2 uses four L3 cache-ways (mask 0xf), CPUs 3-5 share four L3 cache-ways (mask
0xf0), L3 cache-ways used by CPU 2 and 3-5 are non-overlapping
-t 'l3=0xf;cpu=0-2' -t 'l3=0xf0;cpu=3,4,5'
CPUs 0-2 share four L3 cache-ways (mask 0xf), CPUs 3-5 share four L3 cache-ways
(mask 0xf0), L3 cache-ways used by CPUs 0-2 and 3-5 are non-overlapping
-t 'l3=0xf,0xf0;cpu=1'
On CDP enabled system, CPU 1 uses four cache-ways for code (mask 0xf) and four
cache-ways for data (mask 0xf0), data and code cache-ways are non-overlapping
-t 'mba=70;cpu=0-2'
CPUs 0-2 can utilize up to 70% of available memory bandwidth
-t 'mba=50;l3=0xf;cpu=1'
CPU 1 uses four L3 (mask 0xf) cache-ways and can utilize up to 50% of available
memory bandwidth
-t 'mba_max=2000;cpu=1-2' Use SW controller to limit local memory B/W on cores 1-2
to 2000MBps (SW controller uses MBL monitoring and adjust MBA rate).
Example PID type allocation configuration (requires -I option):
-t 'l3=0xf'
Allocate four L3 (mask 0xf) cache-ways to specified PIDs (-p option) or command
-t 'l3=0xf;cpu=1;l3=0x1'
CPU 1 uses four L3 (mask 0xf) cache-ways
Specified PIDs (-p option) or command uses one L3 (mask 0x1) cache-way
-c <cpulist>, --cpu <cpulist>
Specify CPU affinity configuration, a numerical list of processors. The numbers are
separated by commas and may include ranges. For example: 1-3,4,5.
-p <pidlist>, --pid <pidlist>
Operate on existing PIDs
-r <cpulist>, --reset <cpulist>
Reset allocation for CPUs (assign COS#0 to listed CPUs)
For example:
-r 0-5
Reset allocation for CPUs 0-5
-r 0-5 -t 'l3=0xf0;cpu=0-5' -c 0-5 -p $BASHPID
Reconfigure allocation for CPUs 0-5
In order to reconfigure allocation, it is needed to reset current configuration
-k, --sudokeep
Do not drop sudo elevated privileges
NOTES
If kernel interface is not selected neither manually (e.g. --iface=msr) nor automatically,
CAT and MBA are configured using Model Specific Registers (MSRs) to set up the class of
service masks and manage the association of the cores/logical threads to a class of
service. The rdtset software executes in user space, and access to the MSRs is obtained
through a standard Linux*/FreeBSD* interface. Under Linux, the virtual file system
structure /dev/cpu/CPUNUM/msr provides an interface to read and write the MSRs, under
FreeBSD it is /dev/cpuctlCPUNUM. The msr/cpuctl file interface is protected and requires
root privileges. The msr/cpuctl driver might not be auto-loaded and on some modular
kernels the driver may need to be loaded manually:
Under Linux:
sudo modprobe msr
Under FreeBSD:
sudo kldload cpuctl
Interface enforcement:
If you require system wide interface enforcement you can do so by setting the "RDT_IFACE"
environment variable.
OS interface (--iface-os, -I)
With --iface-os (-I) parameter, rdtset uses resctrl filesystem (/sys/fs/resctrl) instead
of accessing MSRs directly.
SEE ALSO
msr(4)
AUTHOR
rdtset was written by Wojciech Andralojc <wojciechx.andralojc@intel.com>, Tomasz Kantecki
<tomasz.kantecki@intel.com>, Michal Aleksinski <michalx.aleksinski@intel.com>, Marcel
Cornu <marcel.d.cornu@intel.com>
This is free software; see the source for copying conditions. There is NO warranty; not
even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
January 10, 2019 RDTSET(8)