What does "m" mean in mpstat?

Question

I check the manual of mpstat it states:

The mpstat command writes to standard output activities for each available processor, processor 0 being the first one. Global average activities among all processors are also reported. The mpstat command can be used both on SMP and UP machines, but in the latter, only global average activities will be printed. If no activity has been selected, then the default report is the CPU utilization report.

However, I didn't get the idea what does m mean in mpstat? is it multiple?

Answer 1

It's unclear exactly what the M in mpstat means. NOTE: mpstat is part of the sysstat package and so is part of a family of *stat tools:

$ rpm -ql sysstat | grep /bin/
/usr/bin/cifsiostat
/usr/bin/iostat
/usr/bin/mpstat
/usr/bin/nfsiostat-sysstat
/usr/bin/pidstat
/usr/bin/sadf
/usr/bin/sar
/usr/bin/tapestat

It's likely the case that the M stands for one of the following:

• multi-processor
• multiple-processors
• microprocessor
• machine
• monitor

Given the top of the mpstat.c source code describes it as this:

• mpstat: per-processor statistics

I'd be inclined to go with the multiple. This seems to be consistent with the source code if you glance through it, given it goes out of its way to deal with both single (UP) and multiple CPUs (SMP).

Example comments from code:

• Structures used to save CPU and NUMA nodes CPU stats
• Compute CPU "all" as sum of all individual CPU (on SMP machines and look for offline CPU.
• Read total number of interrupts received among all CPU.
• What is the highest processor number on this machine?

NOTE: One thing I find curious with this tool, is that if the M is meant to represent multi*, this word never actually appears in the source code, mpstat.c.

References

• Wikipedia - mpstat
• sysstat utilities

Answer 2

According to Linux Magazine it looks like "multi-processor". I'm sure "multiple processor" would work, too.

Answer 3

mpstat is from the first multi processor enhancements from SunOS-4.x.

There is no hint to multi processor in the source code nor in the man page, so there it could only be seen as an obvious explanation.