Measure Reference Manual

Counter type: Queue.
PRES-PAGES-START
Number of pages in main memory sponsored by the measured process at the start of the
measurement interval.
Counter type: Snapshot.
READY-TIME
The time that the measured process spent on the ready list or executing.
To keep the measurement overhead to a minimum, this counter is not turned off during certain
system activities. This counter includes:
• Time required to dispatch the process.
• Time spent in software interrupts that are invoked asynchronously to the executing process.
• Time spent waiting for a page fault to be satisfied by the memory manager. (D-series)
• Time spent in message system routines. (D-series)
• Time spent in low-level message system routines when the process receives data or a message
and the data transfer is not complete. The process is then suspended without being taken off
the ready list timer. For example, a process might remain in the ready timer, not executing,
while waiting for completion of a transfer of ServerNet or FOX data. (G-series)
Due to changes in memory handling, the results of the READY-TIME counter for G05 and later
RVUs are not directly comparable to earlier measurements. Previously, the ready list timer for a
process remained active while waiting for a page fault even if the memory manager subsequently
stalled waiting on I/O for the needed page. As of G05, each process handles its own page fault
requests. If a request stalls while waiting for an I/O completion for the needed page, the ready
timer is turned off.
Counter type: Busy.
NOTE: Measure data can exhibit a combination of high PROCESS.READY-TIME and
CPU.CPU-QTIME while having low PROCESS.CPU-BUSY-TIME and low overall processor utilization.
Prior to G05, this was due to the suspension of PROCESS.CPU-BUSY-TIME while waiting for
completion of a page fault. However, in all RVUs, a process can also be suspended while waiting
for incomplete message system transfers to attempt completion. In either case, the
PROCESS.READY-TIME and CPU.CPU-QTIME counters continue to accumulate. Although this
message system behavior is rare, its occurrence might signal congested FOX or ServerNet/FX
networks, possibly the result of paths in the network being marked as down, underlying hardware
problems in the network, or data overload.
RECEIVED-BYTES
Number of message bytes received by the listener process. The message bytes are also included
in the SENT-BYTES counter of the linker process that sent the message.
In G-series and earlier RVUs, this is a 32-bit counter. In H-series and J-series RVUs, this is a 64-bit
counter.
The G-series RECEIVED-BYTES-F field is a 64-bit version of RECEIVED-BYTES.
Counter type: Accumulating.
RECEIVED-CBYTES
Number of protocol control bytes received by the message system on behalf of this process. This
counter is updated when the process is acting as a listener process. The protocol control bytes are
not included in the counter RECEIVED-BYTES.
306 Entities and Counters