DOKK / manpages / debian 11 / powerpc-ibm-utils / vcpustat.8.en
VCPUSTAT(8) Linux on Power Service Tools VCPUSTAT(8)

vcpustat - Report logical partition (LPAR) dispatch statistics.

/usr/sbin/vcpustat [ options ] [ <interval> [ count ] ]

The vcpustat command provides a report of logical processor (vcpu) dispatch statistics. This command provides a display of the logical processor dispatch dispersions, relative to the previous dispatch, as well as relative to the logical processor's home node as indicated by the Hypervisor.

The vcpustat command with no options will generate a single report containing raw dispatch counts since the last time statistics were enabled. This is useful if dispatch statistics have been previously enabled persistently using the -e option.

The following information is displayed in the report for each logical processor:

Represents logical processor dispatch dispersions, relative to the previous dispatch and includes the below columns:
Indicates the total number of dispatches of this logical processor. This is only displayed if numeric or raw values are being shown.
Indicates the number of times this logical processor was dispatched within the same core.
Indicates the number of times this logical processor was dispatched in a different core, but within the same chip.
Indicates the number of times this logical processor was dispatched in a different chip, but within the same socket. This is only seen on Multi Chip Modules.
Indicates the number of times this logical processor was dispatched outside the socket.
Represents logical processor dispatch dispersions, relative to the logical processor's home node and includes the below columns:
Indicates the number of times this logical processor was dispatched in its home node.
Indicates the number of times this logical processor was dispatched in the adjacent node.
Indicates the number of times this logical processor was dispatched in a further node.

Enable gathering dispatch statistics persistently, and not only when this command is active.
Disable gathering dispatch statistics.
Display the values in numbers, rather than percentages.
Display the raw values, rather than the delta.
Display the usage of vcpustat.
Display the vcpustat version information.
The interval parameter specifies the amount of time between each report.
The count parameter specifies how many reports will be displayed.

The preferred invocation of vcpustat is by specifying interval and an optional count to monitor logical processor dispatch dispersions over a desired interval of time. This enables in-kernel gathering of logical processor dispatch dispersions and provides a view of the same at the desired monitoring interval. With this form of invocation, the statistics are only gathered when the program is active resulting in minimal kernel overhead.

Long-term statistics can be obtained by enabling gathering of statistics in-kernel through the use of -e option, followed by invocations of vcpustat without any options, or using the -r option to display raw values, rather than the difference in each monitoring interval. This should only be used when long-term statistics are desired and results in additional kernel load. It is imperative that the statistics be disabled using -d option once monitoring is complete.

/proc/powerpc/vcpudispatch_stats

Written by Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>.

Mar 2020 Linux