INDICATE MULTITHREAD

Authorization

Privilege Class: E

Purpose

Use INDICATE MULTITHREAD to display the system's multithreading (MT) status and processor core utilization information.

Usage Notes

For information about configuring multithreading, see the Multithreading Statement in z/VM: CP Planning and Administration. To display thread information, use the QUERY MULTITHREAD command.
To modify the multithreading configuration, use the SET MULTITHREAD
The values listed as rates or utilization are averaged over the interval time. These values might differ from the values obtained from other sources (such as Performance Toolkit for z/VM), which use different algorithms.
The values for productivity, utilization, capacity factor, and maximum capacity factor are rounded to the nearest whole number. More precise numbers and core run times are available from sample monitor records.
The interval time is listed on the second line of output when multithreading is enabled. Usually this interval time will be 30 seconds; however, certain long running tasks (for example, SNAPDUMP) might cause the interval time to be longer.

Responses

Response 1:

The Multithreading Facility is not installed.

is displayed if the multithreading facility is not installed on the hardware or the logical partition, or if the z/VM® system is running as a guest.

Response 2:

Multithreading is disabled.

is displayed if the processor or configuration supports multithreading but multithreading is disabled. There are a number of reasons why multithreading might be disabled. For example, a MULTITHREADING statement might not be included in the system configuration file. Review the system initialization messages in the operator's console log.

Response 3:

Multithreading is enabled.
An error occurred in the HISMT service. Use of the service is disabled.

is displayed if the processor or configuration supports multithreading but an error occurred while setting up the HISMT service to collect multithreading statistics. At the time of the error, an MTC001 soft abend should have been generated. Collect the dump and contact your IBM® Support Center personnel.

Response 4:

Multithreading is enabled.
Statistics from the interval hh:mm:ss - hh:mm:ss
Core Type xxxx Busy bbb%   TD ee.ee of tt   Prod ddd%   Util ggg%
  CF ffff%   MaxCF mmmm%
Core Type xxxx Busy bbb%   TD ee.ee of tt   Prod ddd%   Util ggg%
  CF ffff%   MaxCF mmmm%
⋮

is displayed if the processor or configuration supports multithreading and multithreading is enabled in the system configuration file. A Core Type section is displayed if a core of that CPU type is online in the configuration.

hh:mm:ss

is the time stamp for the start and end times of the statistics interval shown in this response. Leading zeros are not removed.

Core Type xxxx

indicates the start of a section of information about cores of a certain CPU type. A Core Type section is displayed for each CPU type with at least one processor online in the configuration. The core type xxxx is one of the following:

CP: indicates this section pertains to central processor (that is, general-purpose processor) cores.
IFL: indicates this section pertains to IBM Integrated Facility for Linux® processor cores.
ZIIP: indicates this section pertains to IBM z Integrated Information Processor cores.
ICF: indicates this section pertains to Internal Coupling Facility processor cores.

Busy bbb%

indicates the multithreading core busy time for cores of a certain CPU type. Multithreading core busy time is the percentage of the interval time that the core was in use. The value bbb is a decimal number 0 - 100 with leading zeros removed. If all cores of this type were recently varied online, or if there was an error collecting data, the value will be ---.

TD ee.ee

indicates the average of the multithreading core thread density for cores of a certain CPU type. Multithreading core thread density is the average number of threads in use while the core was in use. Periods of time when no thread was in use are ignored. The value ee.ee is dependent on the number of threads per core. Leading zeros are removed. If all cores of this type were recently varied online, or if there was an error collecting data, the value will be -----.

of tt

indicates the number of online (activated) threads per core for this CPU type. This number is based on the available hardware, software, and information from the system configuration file. The value tt is a 1- to 2-digit decimal number with leading zeros removed. For the definition of activated threads, see the explanation of the Activated Threads field in the response for the QUERY MULTITHREAD command.

Prod ddd%

indicates the multithreading core productivity for cores of a certain CPU type. Multithreading core productivity is the percentage of the maximum core capacity that was used while the logical core was dispatched on physical hardware. The value ddd is a decimal number 0 - 100 with leading zeros removed. If the value is 100, all threads on the core are executing work and all core resources are being used. If all cores of this type were recently varied online, or if there was an error collecting data, the value will be ---.

Util ggg%

indicates the multithreading core utilization for cores of a certain CPU type. Multithreading core utilization is the percentage of the maximum core capacity that was used during the interval. The value ggg is a decimal number 0 - 100 with leading zeros removed. If all cores of this type were recently varied online, or if there was an error collecting data, the value will be ---.

CF ffff%

indicates the multithreading capacity factor (CF) for cores of a certain CPU type. The multithreading capacity factor is an estimate of the ratio of the amount of work that has been accomplished to the amount of work that would have been accomplished if multithreading was disabled. The value ffff is a 1- to 4-digit decimal number with leading zeros removed. A value over 100% indicates that more work was accomplished with multithreading enabled. If all cores of this type were recently varied online, or if there was an error collecting data, the value will be ----.

MaxCF mmmm%

indicates the multithreading maximum capacity factor for cores of a certain CPU type. The multithreading maximum capacity factor is an estimate of the ratio of the maximum amount of work for the current workload that could be accomplished if all activated threads of the core were kept running, to the amount of work that would have been accomplished if multithreading was disabled. The value mmmm is a 1- to 4-digit decimal number with leading zeros removed. If every thread can run this workload concurrently with no interference from the activity of other threads on the same core, the MaxCF value is the number of threads multiplied by 100%. If all cores of this type were recently varied online, or if there was an error collecting data, the value will be ----.

Response 5:

A speed change was detected during this interval.

is displayed if a change in the speed for a processor type was detected during this interval. In this case, the statistics for utilization, productivity, capacity factor, and maximum capacity factor might not be valid. Wait until the next interval to get a valid sample. This line will appear after the capacity factor information for each core type affected by the change.

Response 6:

A multithreading configuration change was detected during this
  interval for CPU types <CP  > <ZIIP> <ICF > <IFL >

is displayed if a change in the multithreading configuration for a processor type occurred during the interval or is in progress due to a request made by a SET MULITHREAD command. This response line follows the rest of the normal response and includes a list of the CPU types affected by the change. In the response for each of the affected CPU types, the statistics for utilization, productivity, capacity factor, and maximum capacity factor will usually contain dashes if they cannot be calculated due to the transition. Wait until the next interval to get a valid sample.

Example

If the ENABLE operand was specified on the MULTITHREADING statement in the system configuration file, and you issue the INDICATE MULTITHREAD command on a system that is capable of multithreading, you might see a response similar to the following example.

indicate mt
Multithreading is enabled.
Statistics from the interval 13:00:30 - 13:01:00
Core Type CP   Busy   8%   TD  1.00 of  1   Prod 100%   Util   8%
  CF  100%   MaxCF  100%
Core Type IFL  Busy  67%   TD  1.24 of  2   Prod  82%   Util  55%
  CF  107%   MaxCF  131%
Core Type ZIIP Busy   5%   TD  1.00 of  1   Prod 100%   Util   5%
  CF  100%   MaxCF  100%

If a speed change was detected for CP and specialty processors, you might see a response similar to the following example.

indicate mt
Multithreading is enabled.
Statistics from the interval 13:00:30 - 13:01:00
Core Type CP   Busy   8%   TD  1.00 of  1   Prod 100%   Util   8%
  CF  100%   MaxCF  100%
A speed change was detected during this interval.
Core Type IFL  Busy  67%   TD  1.24 of  2   Prod  82%   Util  55%
  CF  107%   MaxCF  131%
A speed change was detected during this interval.
Core Type ZIIP Busy   5%   TD  1.00 of  1   Prod 100%   Util   5%
  CF  100%   MaxCF  100%
A speed change was detected during this interval.

If an SMT configuration change is detected for IFL processors, you might see a response similar to the following example.

indicate mt
Multithreading is enabled.
Statistics from the interval 16:07:30 - 16:08:00
Core Type CP   Busy   8%   TD  1.00 of  1   Prod 100%   Util   8%
  CF  100%   MaxCF  100%
Core Type IFL  Busy ---%   TD ----- of --   Prod ---%   Util ---%
  CF ----%   MaxCF ----%
Core Type ZIIP Busy   5%   TD  1.00 of  1   Prod 100%   Util   5%
  CF  100%   MaxCF  100%
A multithreading configuration change was detected during this
interval for CPU types IFL

For an example showing the relationship among the INDICATE MULTITHREAD, QUERY MULTITHREAD, and QUERY PROCESSORS commands, see QUERY MULTITHREAD.