lgrpinfo - display information about locality groups
lgrpinfo [-aceGlLmrt] [-u unit] [-C | -P] lgrp ...
lgrpinfo -I [-c] [-G] [-C | -P] lgrp ...
lgrpinfo [-T] [-aceGlLmr] [-u unit]
lgrpinfo -d device_path
lgrpinfo prints information about the locality group (lgroup) hierarchy and its contents.
An lgroup represents the set of CPU and memory-like hardware devices that are at most some distance (latency) apart from each other. All lgroups in the system are identified by a unique integer called an lgroup ID.
lgroups are organized into a hierarchy to facilitate finding the nearest resources. Leaf lgroups each contain a set of resources that are closest (local) to each other. Each parent lgroup in the hierarchy contains the resources of its child lgroups plus their next nearest resources. Finally, the root lgroup contains all the resources in the domain within the largest latency.
A Uniform Memory Access (UMA) machine is simply represented by the root lgroup. A Non Uniform Memory Access (NUMA) machine is represented by a hierarchy of lgroups to show the corresponding levels of locality. For example, a NUMA machine with two latencies (local and remote) has an lgroup hierarchy consisting of two levels with its leaves and the root.
Every application thread is assigned a home lgroup. When the system needs to allocate a CPU or memory resource for a thread, it searches lgroup hierarchy from the thread's home lgroup for the closest available resources to the thread's home. See plgrp(1) for details.
Without arguments, lgrpinfo prints general information about all lgroups in the system. If any lgroup IDs are specified on the command line, the command only prints information about the specified lgroups. Various options control which lgroups are displayed and the exact information that is printed for each lgroup.
lgroups can be specified on the command line as lgroup IDs or by using specific keywords. See OPERANDS.
You can combine options together and the order in which options are specified is not important. Lowercase options select what information should be printed about lgroups.
Invoking lgrpinfo without arguments is equivalent to:
lgrpinfo -c -e -l -m -r -t all
The following options are supported:
Print topology, CPU, memory, load and latency information.
This option is a shorthand for
lgrpinfo -t -c -e -m -r -l -L
unless –T is specified as well. When –T is specified, the –t option is not included.
Print CPU information.
This is the default.
Replace each lgroup in the list with its children.
This option cannot be used with the –P or the –T option. When no arguments are specified, this option is applied to the lgroups displayed by default.
Print IDs of lgroups closest to the specified I/O device. device_path is a string representing the device path.
Print lgroup load average. The lgroup load averages are only displayed for leaf lgroups.
This is the default.
Print OS view of lgroup hierarchy.
By default, the caller's view of the lgroup hierarchy is displayed which only includes what the caller can use, for example, only the CPUs in the caller's processor set is displayed. See lgrp_init(3LGRP) on the operating system and the caller's view.
Print short help message and exit.
Print matching IDs only.
This option is intended for scripts and can be used with –c, –G, and –C or –P. If –c is specified, print list of CPUs contained in all matching lgroups. Otherwise, the IDs for the matching lgroups is displayed. See EXAMPLES.
When no arguments are specified, this option is applied to the lgroups displayed, which, by default is all lgroups.
Print information about lgroup latencies.
The latency value specified for each lgroup is defined by the operating system and is platform-specific. It can only be used for relative comparison of lgroups on the running system. It does not necessarily represent the actual latency between hardware devices and might not be applicable across platforms.
Print the lgroup latency table. The lgroup latency table displays the relative latency from each lgroup to each of the other lgroups including itself.
Print memory information.
Memory sizes are scaled to the unit of measure that yields an integer from 0 to 1023 unless the –u option is specified as well. The fractional part of the number is only displayed for values less than 10. This behavior is similiar to using the –h option of ls(1) or df(1M) to display a human readable format.
This is the default.
Replace each lgroup in the list with its parents.
This option cannot be used with the –C or –T option. When no arguments are specified, this option is applied to the lgroups displayed, which, by default is all lgroups.
Print information about lgroup resources.
The resources are represented by a set of lgroups in which each member lgroup directly contains CPU and memory resources. If –T is specified as well, only information about resources of the intermediate lgroups is displayed.
Print information about lgroup topology.
This is the default.
Print the lgroup topology of a system graphically as a tree. This option can only be used with the –a, –c, –e, –G, –l,–L, –m, –r, and – u options. It only prints lgroup resources for intermediate lgroups when used with the –r. The –t option is omitted when –T is used with –a. No information is printed for the root lgroup unless it is the only lgroup.
Specify memory units. Units should be b, k, m, g, t, p, or e for bytes, kilobytes, megabytes, gigabytes, terabytes, petabytes, or exabytes respectively. The fractional part of the number is only displayed for values less than 10. This behavior is similiar to using the –h option of ls(1) or df(1M) to display a human readable format.
The following operands are supported:
lgroups can be specified on the command line as lgroup ID, by using one of the following keywords:
This is the default.
All intermediate lgroups. An intermediate lgroup is an lgroup that has a parent and children.
All leaf lgroups. A leaf lgroup is an lgroup that has no children in the lgroup hierarchy.
Root lgroup. Root lgroup contains all the resources in the domain within the largest latency and has no parent lgroup.
If an invalid lgroup is specified, the lgrpinfo command prints a message on standard error showing the invalid ID and continues processing other lgroups specified on the command line. When none of the specified lgroups are valid, lgrpinfo exits with an exit status of 2.
The following example prints general information about lgroups in the system.
In this example, the system is a 2 CPU AMD Opteron machine with two nodes, each having one CPU and 2 gigabytes of memory. Each of these nodes is represented by a leaf lgroup. The root lgroup contains all the resources in the machine:
$ lgrpinfo lgroup 0 (root): Children: 1 2 CPUs: 0 1 Memory: installed 4.0G, allocated 2.2G, free 1.8G Lgroup resources: 1 2 (CPU); 1 2 (memory) Latency: 83 lgroup 1 (leaf): Children: none, Parent: 0 CPU: 0 Memory: installed 2.0G, allocated 1.2G, free 788M Lgroup resources: 1 (CPU); 1 (memory) Load: 0.793 Latency: 56 lgroup 2 (leaf): Children: none, Parent: 0 CPU: 1 Memory: installed 2.0G, allocated 1017M, free 1.0G Lgroup resources: 2 (CPU); 2 (memory) Load: 0.817 Latency: 56Example 2 Printing lgroup Topology
The following example prints the lgroup topology tree on a 4 CPU AMD Opteron machine:
$ lgrpinfo -T 0 |-- 5 | `-- 1 |-- 6 | `-- 2 |-- 7 | `-- 3 `-- 8 `-- 4Example 3 Printing lgroup Topology
The following example prints the lgroup topology tree, resources, memory and CPU information on a 2 CPU AMD Opteron machine:
$ lgrpinfo -Ta 0 |-- 1 | CPU: 0 | Memory: installed 2.0G, allocated 1.2G, free 790M | Load: 0.274 | Latency: 56 `-- 2 CPU: 1 Memory: installed 2.0G, allocated 1019M, free 1.0G Load: 0.937 Latency: 56 Lgroup latencies: ------------ | 0 1 2 ------------ 0 | 83 83 83 1 | 83 56 83 2 | 83 83 56 ------------Example 4 Printing lgroup IDs
The following example prints lgroup IDs for children of the root lgroup:
$ lgrpinfo -I -C root 1 2Example 5 Printing CPU IDs
The following example prints CPU IDs for all CPUs in lgroup 1:
$ lgrpinfo -c -I 1 0Example 6 Printing Information about lgropu Latencies
The following example prints information about lgroup latencies:
$ lgrpinfo -l lgroup 0 (root): Latency: 83 lgroup 1 (leaf): Latency: 56 lgroup 2 (leaf): Latency: 5Example 7 Printing IDs of lgroups Closest to a Given Device
The following example demonstrates that lgroups 2 and 6 are closest to the given device:
$ lgrpinfo -d /dev/dsk/c9t0d0s0 lgroup IDs : 2 6
The following exit values are returned:
Unable to get lgroup information from the system.
All lgroups or the device_path specified are invalid.
See attributes(5) for descriptions of the following attributes:
The human readable output is Uncommitted.