Reading statistics for a PCIe device

Red Hat Enterprise Linux 9.2 LPAR mode z/VM guest KVM guest

Use the statistics attribute file to see measurement data for a PCIe device.

About this task

All PCIe devices collect measurement data by default. You can read the data in a sysfs attribute file in the debug file system, by default mounted at /sys/kernel/debug.

You can turn data collection on and off. To switch off measurement data collecting for the current session, write "0" to the statistics attribute. To enable data collection again, write "1" to the statistics attribute.

Example

To read measurement data for a (RoCE) function named 0000:00:00.0 use:

# cat /sys/kernel/debug/pci/0000:00:00.0/statistics

The statistics attribute file might look similar to this example:

FMB @ 0000000078cd8000
Update interval: 4000 ms
Samples: 14373
Last update TOD: cefa44fa50006378
           Load operations:     1002780  
          Store operations:     1950622
    Store block operations:     0
        Refresh operations:     0
            Received bytes:     0
          Received packets:     0
         Transmitted bytes:     0
       Transmitted packets:     0
           Allocated pages:     9104
              Mapped pages:     16633
            Unmapped pages:     2337