Commit Graph

5 Commits

Author SHA1 Message Date
Peter Oberparleiter 338bea49c2 chpstat: Clarify scope of --scale option
Add a man page note to clarify that BPS value scaling only applies to
human-readable output format.

Reviewed-by: Vineeth Vijayan <vneethv@linux.ibm.com>
Signed-off-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>
2025-09-15 11:12:15 +02:00
Peter Oberparleiter d15e36cf24 chpstat: Add options to select IEC units for scaling
Add options to select power-of-two based IEC units such as KiB/s
(1024 B/s) for scaling throughput values in human readable reports.

Option            Scaling factor
================================
--scale ki        1024
--scale mi        1048576
--scale gi        1073741824
--scale auto-iec  IEC units

Reviewed-by: Jimmy Brisson <jbrisson@linux.ibm.com>
Reviewed-by: Vineeth Vijayan <vneethv@linux.ibm.com>
Signed-off-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>
2025-09-15 11:12:15 +02:00
Peter Oberparleiter 4b76530788 chpstat: Use SI units for default scaling
chpstat uses power-of-two based IEC units such as KiB/s (1024 B/s) when
scaling throughput values in human readable reports. A user interpreting
these numbers can easily be confused by chpstat's default column header
("B/s") to assume that numbers are scaled using power-of-ten based SI
units such as kB/s (1000 B/s).

In addition, users that have worked with similar z/OS tooling to display
channel path activity are used to SI-based scaling, which increases the
chance of chpstat reports being misinterpreted.

To reduce this confusion, use SI units for throughput scaling:

Option          Old factor      New factor
==========================================
--scale k       1024            1000
--scale m       1048576         1000000
--scale g       1073741824      1000000000
--scale auto    IEC units       SI units

Note that machine-readable format produced via option --format is not
affected by scaling.

Reviewed-by: Jimmy Brison <jbrisson@linux.ibm.com>
Reviewed-by: Vineeth Vijayan <vneethv@linux.ibm.com>
Signed-off-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>
2025-09-15 11:12:15 +02:00
Peter Oberparleiter 482bd93e2e chpstat: Add support for new CMG types
New machine models introduce CHPIDs with two new CMG types 4 and 5.
Add support for decoding the associated channel-measurement data.

Reviewed-by: Vineeth Vijayan <vneethv@linux.ibm.com>
Signed-off-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
2024-11-29 15:52:24 +01:00
Peter Oberparleiter cb77faeae7 chpstat: add tool to display channel-path statistics
Add a new tool named chpstat that can be used to view channel-path
statistics such as utilization and I/O throughput, and to query and
control the status of the channel-path statistics function.

Note: Channel-path statistics are only available on systems running in
      an LPAR or DPM partition.

When run without further options, data for all channel-paths is
displayed repeatedly with a 5 second delay in table format.

Example output:

      CHANNEL-PATH       UTILIZATION(%)   READ(B/s)  WRITE(B/s)
  ID TYP CMG SHR SPEED  PART TOTAL  BUS  PART TOTAL  PART TOTAL
  1d  25   2   1     -  7.16  7.50 7.50  129M  129M  0.00  161K
  21  1b   2   1   32G  0.00  0.00 0.00  0.00  0.00  0.00  0.00
  34  1b   2   1   32G  0.00  0.00 0.00  0.00  0.00  0.00  0.00
  61  25   2   1     -  0.00  0.01 0.00  0.00 2.00K  0.00  307K
  63  25   2   1     -  0.00  0.01 0.00  0.00  0.00  0.00  381K
  bd  11   2   1   10G     -     -    - 529.8 532.1 616.3 616.3

Reviewed-by: Vineeth Vijayan <vneethv@linux.ibm.com>
Signed-off-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>
2024-05-27 16:52:27 +02:00