mpstat Command

Purpose

Collects and displays performance statistics for all logical processors in the system.

Syntax

mpstat [ { -d | -i | -s | -a | -h | -v | -E } ] [ -w ][ -O Options ] [ -@ wparname] [ interval [ count ] ]

mpstat [-X [-o filename]] [interval[count]]

Restriction: The wparname parameter is restricted to use inside workload partitions.

Description

The mpstat command collects and displays performance statistics for all logical processors in the system. Users can define both, the number of times the statistics are displayed, and the interval at which the data is updated.

The interval parameter specifies the amount of time in seconds between each report. If you do not specify the interval parameter, the mpstat command generates a single report that contains statistics for the time since system startup and then exits. You can specify the count parameter only with the interval parameter. If you specify the count parameter, its value determines the number of reports that are generated and the number of seconds apart. If you specify the interval parameter without the count parameter, reports are continuously generated. Do not specify a value of zero to the count parameter.

The mpstat command with no options generates a single report that contains the performance statistics for all logical processors since boot time.

When the mpstat command is invoked, it displays two sections of statistics. The first section displays the System Configuration, which is displayed when the command starts and whenever there is a change in the system configuration. The second section displays the Utilization Statistics which are displayed in intervals and at any time the values of these metrics are deltas from previous interval.

The following information is displayed in the system configuration section:

lcpu: Indicates the number of online logical processors.
ent: Indicates the entitled processing capacity in processor units. This information is displayed only when the partition type is shared.
mode: Indicates whether the partition processor capacity is capped or uncapped allowing it to consume idle cycles from the shared pool. Dedicated LPAR is capped or donating.
rset: Indicates the resource-set type (regular or exclusive) that is associated with the WPAR. This information is displayed only when there is a resource set that is associated with the WPAR.

The performance statistics displayed by mpstat are listed below:

CPU: (All flags) Logical processor ID.
Note: The logical processor ID that is associated with the resource set of a WPAR is prefixed by an asterisk (*) when you run the mpstat command inside a WPAR with the -s or -@ flag.
min: (Default, -a flag) Minor page faults (page faults with no IO).
maj: (Default, -a flag) Major page faults (page faults with disk IO).
mpcs: (-a, -i flag) Number of mpc send interrupts.
mpcr: (-a, -i flag) Number of mpc receive interrupts.
mpc: (Only default) Total number of inter-processor calls .
dev: (-a, -i flag) Number of device interrupts.
soft: (-a, -i flag) Number of software interrupts.
dec: (-a, -i flag) Number of decrementer interrupts.
ph: (-a, -i flag) Number of phantom interrupts.
int: (Only default) Total number of interrupts.
cs: (Default, -a flag) Total number of context switches.
ics: (Default, -a flag) Total number of involuntary context switches.
bound: (-a, -d flag) Total number of threads that are bound.
rq: (Default, -a, -d flag) Run queue size.
push: (-a, -d flag) Number of migrations due to starvation load balancing .
S3pull: (-a, -d flag) Number of migrations outside the scheduling affinity domain 3 due to idle stealing.
S3grd: (-a, -d flag) Number of dispatches from global runqueue, outside the scheduling affinity domain 3.
mig: (Only default) Total number of thread migrations (to another logical processor).
S0rd: (-a, -d flag) The percentage of thread redispatches within the same logical processor with scheduling affinity domain 0.
S1rd: (-a, -d flag) The percentage of thread redispatches within the same physical processor or core with scheduling affinity domain 1.
S2rd: (-a, -d flag) The percentage of thread redispatches within the same chip set, but not within the same processor core with scheduling affinity domain 2.
S3rd: (-a, -d flag) The percentage of thread redispatches within the same MCM (multiple chip module) , but not within the same chip set with scheduling affinity domain 3.
S4rd: (-a, -d flag) The percentage of thread redispatches on different MCMs within the same CEC or Plane with scheduling affinity domain 4.
S5rd: (-a, -d flag) The percentage of thread redispatches on a different CEC or Plane with scheduling affinity domain 5.
S3hrd: (-a, -d flag) The percentage of local thread dispatches on this logical processor.
S4hrd: (-a, -d flag) The percentage of near thread dispatches on this logical processor.
S5hrd: (-a, -d flag) The percentage of far thread dispatches on this logical processor.
lpa: (Only default) Logical processor affinity. The percentage of logical processor re-dispatches within the scheduling affinity domain 3.
sysc: (Default, -a flag) Number of system calls.
us: (Default, -a flag, -v flag) The percentage of physical processor utilization that occurred while executing at the user level (application).
If the -v flag is used, then utilization is based on the virtual processor.
sy: (Default, -a flag, -v flag) The percentage of physical processor utilization that occurred while executing at the system level (kernel).
If the -v flag is used, then utilization is based on the virtual processor.
wa: (Default, -a flag, -v flag) The percentage of time that the logical processor was idle during which it had an outstanding disk I/O request.
If the -v flag is used, then utilization is based on the virtual processor.
id: (Default, -a flag, -v flag) The percentage of time that the logical processor was idle and it did not have an outstanding disk I/O request.
If the -v flag is used, then utilization is based on the virtual processor.
pc: (Default, -a flag, -h flag, -v flag) The number or fraction of physical processor consumed. It is displayed in both a shared partition and a dedicated partition. For the default flag in the dedicated partition, it is not displayed when both donation and simultaneous multithreading are disabled.
The pc of the cpuid U row represents the number of unused physical processors.
%ec: (Default, -a flag) The percentage of entitled capacity consumed by the logical processor. The %ec of the ALL CPU row represents the percentage of entitled capacity consumed. Because the time base over which this data is computed can vary, the entitled capacity percentage can sometimes exceed 100%. This excess is noticeable only with small sampling intervals. The attribute is displayed only in a shared partition.
ilcs: (-a, -d, -h flag) Number of involuntary logical processor context switches, displayed only in shared partition. For the -h and -a flags, it is also displayed in dedicated partition.
vlcs: (-a, -d, -h flag) Number of voluntary logical processor context switches. Displayed only in shared partition. For the -h and -a flags, it is also displayed in dedicated partition.
lcs: (Default) Total number of logical processor context switches. Displayed only in shared partition or when a dedicated partition is donating.
%idon: (-a, -h flag) Shows the percentage of physical processor utilization that occurs while explicitly donating idle cycles. Displayed only in dedicated partition that is donating.
%bdon: (-a, -h flag) Shows the percentage of physical processor utilization that occurs while donating busy cycles. Displayed only in dedicated partition that is donating.
%istol: (-a, -h flag) Shows the percentage of physical processor utilization that occurs while the Hypervisor is stealing idle cycles. Displayed only in dedicated partition.
%bstol: (-a, -h flag) Shows the percentage of physical processor utilization that occurs while the Hypervisor is stealing busy cycles. Displayed only in dedicated partition.
%nsp: (-a, -d flag) Shows the current average processor speed as a percentage of nominal speed. Displayed only if the hardware uses Scaled Processor Utilization Resource Register (SPURR).
vcpu: (-v flag) Shows the virtual processor id.
lcpu: (-v flag) Shows the logical processor id.
pbusy: (-v, -E flag) Shows the percentage of physical time during which the physical processor is busy.
VTB: (-v flag) Shows the time taken for a virtual processor in milliseconds.
physc: (-E flag) Shows the number of physical processors that are used by the logical processor.
freq: (-E flag) Shows the operating frequency in GHz.
scaled physc: (-E flag) Shows the number of physical processors that are used by the logical processor based on SPURR.

The mpstat command displays all the above statistics for every logical processor in the partition. When running a shared partition, a special processor row with the cpuid U can be displayed when the entitled processing capacity has not entirely been consumed.

The mpstat command also displays a special processor row with the cpuid ALL which shows the partition-wide utilization. On that row, except for uncapped partitions with current physical processor consumption above their entitled capacity, the percentages are relative to the entitled processing capacity. For dedicated partitions, the entitled processing capacity is the number of physical processors. And for a WPAR , the processors present in the associated resource set, if any, are indicated by asterisks (*) only when the -s or -@ flag is used.

When the -s flag is specified, the mpstat command reports simultaneous multithreading utilization, if it is enabled. This report displays the virtual processor engines utilization and utilization of each thread (logical processor) associated with the virtual processor engine.

If mpstat is running in a dedicated partition and simultaneous multithreading is enabled, then only the thread (logical processor) utilization is displayed.

If mpstat is running on an interval based mode, then it would be average value calculated per second.

Flags

Item	Description
-a	Displays all the statistics.
-d	Displays detailed affinity and migration statistics for AIX® threads and dispatching statistics for logical processors.
-i	Displays detailed interrupts statistics.
-s	Displays simultaneous multithreading threads utilization, this flag is available only when mpstat runs in a simultaneous multithreading enabled partition.
-h	Displays pc and processor switches, with stolen and donation statistics for dedicated partitions.
-w	Displays wide column output, switches to wide output mode. Default is 80 column output mode.
@ wparname	Displays the statistics for the specified WPAR.
-O Options	Specifies the command option. -O options=value... Following are the supported options: sortcolumn = Name of the metrics in the mpstat command output sortorder = [asc\|desc] topcount = Number of CPUs to be displayed in the mpstat command sorted output
-X	Generates the XML output. The default file name is mpstat_DDMMYYHHMM.xml unless you specify a different file name by using with the –o option.
-o	Specifies the file name for the XML output.
-v	Displays utilization statistics at the virtual processor level. Note: The -v flag is available only for POWER8® processors, and later.
-E	Displays SPURR-based utilization metrics on a SPURR-capable processor.

Note:

The -a, -d, and -i flags implicitly turn on wide-column output.
Inside a WPAR, the -@ flag reports statistics of all processors.
Processor statistics that are displayed inside a WPAR is always system wide.
Only -o option is allowed with -X option.

Parameters

Item	Description
interval	Specifies the interval between the iterations. If interval is not specified, just one snapshot of metrics is displayed which actually reports the values from the time system is up. If interval is specified, the tool waits for that duration before printing the first set of data. Each set of data is followed by a separation line, a line with average values for each columns (except the processor, which is replaced by ALL), followed by an empty line.
count	Specifies number of iterations. If interval is specified and count is not specified then mpstat runs infinitely. count can not be specified without specifying interval.

Item

Description

interval

Specifies the interval between the iterations. If interval is not specified, just one snapshot of metrics is displayed which actually reports the values from the time system is up. If interval is specified, the tool waits for that duration before printing the first set of data. Each set of data is followed by a separation line, a line with average values for each columns (except the processor, which is replaced by ALL), followed by an empty line.

count

Specifies number of iterations. If interval is specified and count is not specified then mpstat runs infinitely. count can not be specified without specifying interval.

Examples

To see the default set of utilization metrics, enter the following command:
```
mpstat 1 1
```
To see the default set of utilization metrics in wide display mode, enter the following command:
```
mpstat –w 1 1
```
To see the detailed dispatch & affinity metrics, enter the following command:
```
 mpstat –d 1 1
```
To see the detailed interrupts report, enter the following command:
```
mpstat –i 1 1
```
To see all the statistics, enter the following command:
```
mpstat –a 1 1
```
To see simultaneous multithreading utilization, enter the following command:
```
mpstat –s 1 1
```
To see all the processor metrics of a WPAR, enter the following command:
```
mpstat -@ wparname
```
Note: To see all the processor metrics of a WPAR inside the WPAR, enter the following command:
```
mpstat -@
```
To see the sorted output for the column cs, enter the following command:
```
mpstat -d -O sortcolumn=cs
```
To see the list of the top 10 CPUs, enter the following command:
```
mpstat -a -O sortcolumn=min,sortorder=desc,topcount=10
```
To see metrics based on the virtual processor, enter the following command:
```
mpstat –v
```

Files

Item	Description
/usr/bin/mpstat	Contains the mpstat command.