The channel-measurement facility

.//arch/s390/include/asm/cmb.h — Document generation inconsistency
enable_cmf — switch on the channel measurement for a specific device
disable_cmf — switch off the channel measurement for a specific device
cmf_read — read one value from the current channel measurement block
cmf_readall — read the current channel measurement block

The channel-measurement facility provides a means to collect measurement data which is made available by the channel subsystem for each channel attached device.