| STRUCT CMBDATA(9) | The ccw bus | STRUCT CMBDATA(9) |
NAME¶
struct_cmbdata - channel measurement block data for user space
SYNOPSIS¶
struct cmbdata {
__u64 size;
__u64 elapsed_time;
__u64 ssch_rsch_count;
__u64 sample_count;
__u64 device_connect_time;
__u64 function_pending_time;
__u64 device_disconnect_time;
__u64 control_unit_queuing_time;
__u64 device_active_only_time;
__u64 device_busy_time;
__u64 initial_command_response_time;
};
MEMBERS¶
size
size of the stored data
elapsed_time
time since last sampling
ssch_rsch_count
number of ssch and rsch
sample_count
number of samples
device_connect_time
time of device connect
function_pending_time
time of function pending
device_disconnect_time
time of device disconnect
control_unit_queuing_time
time of control unit queuing
device_active_only_time
time of device active only
device_busy_time
time of device busy (ext. format)
initial_command_response_time
initial command response time (ext. format)
DESCRIPTION¶
All values are stored as 64 bit for simplicity, especially in 32 bit emulation mode. All time values are normalized to nanoseconds. Currently, two formats are known, which differ by the size of this structure, i.e. the last two members are only set when the extended channel measurement facility (first shipped in z990 machines) is activated. Potentially, more fields could be added, which would result in a new ioctl number.
AUTHOR¶
Cornelia Huck <cornelia.huck@de.ibm.com>
Author.
COPYRIGHT¶
| May 2024 | Kernel Hackers Manual 2.6. |