Commonly used event sets, Modifying the event interval value – HP XC System 3.x Software User Manual

Page 38

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event_set_name

Specifies an event set name.

value

Specifies the event interval, which is the number of times an event is
recorded by the PMU before generating an interrupt for hpcpid to record
a sample.

Range: 2000-65535

Default: 60000

Commonly Used Event Sets

Table 4-1

describes some of the more commonly used event sets. To see a complete list and the

events contained in each group, use the hpcpid -show-event-sets command.

Table 4-1 Commonly Used Event Sets

Description

Event Set Name

A large number (approximately 20) of events, including metrics for instruction
counts, instruction bubbles, and cache delays.

HelpMeEvents

Events for computing instructions per cycle (IPC).

Computing IPC for Itanium processors requires multiple events. See

“Itanium

Instruction Metrics” (page 57)

for more information.

IPCEvents

Events for floating point units (FPUs).

FPUEvents

Events for execution stalls. On AMD processors, this is a moderate number
of events. On Itanium systems, this is a large number of events.

StallEvents

Events for data cache misses. Includes cache misses at different levels.

CacheMissEvents

Data cache events.

DCacheEvents

Instruction cache events.

ICacheEvents

Branch-related events. For example, branch taken, branch not taken, predicted,
mispredicted, predicted correct target, and predicted wrong target.

BranchEvents

Additional branch-related events. Supported on Itanium processors only.

BranchEvents2

Events for basic servers, such as CPU cycles used, stalls, memory loads with
long delays, and retired instructions.

ServerEvents

Events for High Performance Computing (HPC) systems.

HPCEvents

TIP:

If you do not want to run your application multiple times, you can collect a large number

of metrics with the HelpMeEvents event set. This event set enables you to run your application
once and capture events for deriving useful metrics. You can run the HPCPI display utilities
multiple times and select different events for the output.

Modifying the Event Interval Value

Decreasing the event interval value increases the number of interrupts generated to schedule
hpcpid

, which can affect the statistics collected.

If you specify multiple event or event set names with an -events option, the interval qualifier
applies to all specified events or event sets. If you specify an interval qualifier for an event set
and all events in the set have the same default interval, the specified interval applies to all events
in the set. If the events in the set do not have the same default interval, the specified interval
applies to the first event in the set and hpcpid changes the intervals for the other events in the
set to values that retain the relative proportions of the intervals.

38

Using HPCPI

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