HP Caliper User's Guide

processor is being delayed during bus request arbitration, probably due to excessive
bus utilization by a priority agent (I/O).
• AVG IOQ Live Entries Per Cycle
The in-order queue (IOQ) monitors all outstanding bus transactions generated by
any bus agent. Requests are loaded into the IOQ during the bus transaction request
phase. Transactions are retired from the IOQ on receipt of a positive response
status from the bus. This metric provides an estimate of the number of bus
transactions that are live in the IOQ on a per-cycle basis. A high value for this
metric would be indicative of high system bus utilization (many transactions in
flight).
• AVG OOQ Live Entries Per Cycle
If a deferred response is received while a request is live in the IOQ, it is moved to
the out-of-order queue (OOQ). When the response for the deferred transaction is
received, the OOQ entry is moved to the end of the IOQ to complete the processing
of the transaction. This metric provides the average number of requests that are
live in the OOQ per cycle. High numbers of OOQ entries indicates excessive snoop
response timing.
snoop Event Set
Available only on Itanium 9300 quad-core processor systems.
The snoop event set provides data about snoop responses.
If you use this event set, the default is to make the measurements irrespective of CPU
operating state (that is, user, system, or interrupt states). By default, the idle state is
not included in the measurement. You can use command-line options to limit the scope
of the measurement. Specifically, you can:
• Limit measurement to a specific privilege level: -m
event_set[:all|user|kernel]
• Include idle: --exclude-idle False
• Exclude the interruption state: --measure-on-interrupts off
• Only measure the interruption state: --measure-on-interrupts only
Metrics Available from this Measurement
The following metrics are available from this event set. These descriptions do not take
into account any command-line options you might use.
The metrics are:
• Snoops Per Sec
Number of all snoops per second.
• Code
Percentage of snoops that are code snoops.
snoop Event Set 337