hot spot

An instruction or set of instructions that has a higher execution count than most other instructions

 

in a program.

HP Caliper Advisor

A rules-based expert system that gives guidance about improving the performance of an

 

application. See “Using the HP Caliper Advisor” (p. 76).

HP Caliper option

A parameter in the HP Caliper command line used to customize the performance analysis. See

 

“HP Caliper Options” (p. 47).

HyperThreading

A feature of the dual-core Itanium 2 and Itanium 9300 quad-core processor that provides the

 

ability for a processor to create an additional logical processor that might allow additional

 

efficiencies of processing. A dual-core Itanium 2 processor with HyperThreading active provides

 

four logical processors, two on each core. An Itanium 9300 quad-core processor with

 

HyperThreading active provides eight logical processors. This allows the operating system to

 

schedule two threads or processes simultaneously. HyperThreading is formally called

 

Hyper-Threading Technology.

icache

A measurement, provided by the icache measurement configuration file, that measures and

measurement

reports instruction cache misses.

icache_miss

The non-preferred name for the icache measurement. This name was used in releases prior to

measurement

Release 3.9.

index value

In the HP Caliper Advisor, a number representing the approximate importance of a particular

 

piece of advice. See “Using the HP Caliper Advisor” (p. 76).

instruction bundle

In the Integrity servers processor family, a group of three instructions packed into 16 bytes. Also

 

known as bundle.

instruction

The process of mapping instructions within bundles to functional units. See “dispersal Event Set”

dispersal

(p. 227).

instruction event

The component of the Integrity servers processor that records the instruction addresses of data

address register

cache misses for loads, the instruction addresses of data TLB misses, and the instruction addresses

(I-EAR)

of instruction TLB and cache misses.

 

See also data event address register (D-EAR).

instruction pointer

In the Integrity servers processor family, a register that indicates where the computer is in its

(IP)

instruction sequence.

instruction slot

An arrangement of instructions. In the Integrity servers processor family, each instruction bundle

 

is composed of three instruction slots, numbered 0, 1, and 2. Also known as slot.

Integrity servers

A collection of HP processors using the Itanium 2 architecture. These processors include the

processor family

following processors: Itanium 2, Itanium 2 6M, Itanium 2 9M, low-voltage Itanium 2, dual-core

 

Itanium 2, and Itanium 9300 quad-core processor. Report output from HP Caliper specifies

 

whether the output refers to the Itanium 2, Itanium 2 6M, Itanium 2 9M, low-voltage Itanium 2,

 

dual-core Itanium 2, or Itanium 9300 quad-core processor.

IP-EAR

Instruction pointer address capture. This is a feature in dual-core Itanium 2 and Itanium 9300

 

quad-core processors that is intended to facilitate the correlation of performance monitoring events

 

to instruction pointers.

itlb measurement

A measurement, provided by the itlb measurement configuration file, that measures and reports

 

instruction translation lookaside buffer (TLB) misses.

itlb_miss

The non-preferred name for the itlb measurement. This name was used in releases prior to

measurement

Release 3.9.

latency bucket

A grouping of latency data associated with data accesses serviced by particular levels of CPU

 

cache and system memory. The dcache measurement provides latency bucket information.

leaf routine

A routine that is a leaf in the call graph of a program (that is, a routine that calls no other routines).

measurement

An activity performed by HP Caliper to quantify the performance of an application. Each run of

 

HP Caliper uses a particular measurement, which you can specify in the command line. A

 

measurement is actually the name of a measurement configuration file that contains parameter

 

settings for the measurement to be made. See “HP Caliper Measurement Configuration Files”

 

(p. 42).

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