HP Caliper User's Guide

ecount Measurement Report Description
With the ecount measurement, produced by the ecount measurement configuration
file, HP Caliper measures and reports total counts of processor metrics accumulated
during an application's execution under HP Caliper control. These metrics are collected
using the processor's performance monitoring unit (PMU).
The number of metrics HP Caliper can accumulate during a single run of your
application is limited to four by PMU constraints. The processor metrics you can choose
from are listed in the file itanium2_cpu_counters.txt, located in the HP Caliper
home directory in the doc/text subdirectory.
By default, the ecount measurement is set up for recording processor events needed
for calculating cycles per instruction (CPI). If you do not change the default processor
events, HP Caliper reports CPI as well as event counts.
Example Command Line for Text Report
$ caliper ecount -o reports/ecount.txt ./wordplay thequickbrownfox
Example Command Line for CSV Report
$ caliper ecount --csv reports/csvout ./wordplay thequickbrownfox
ecount Metrics Summed for Entire Run
This section describes the metrics summed over the entire run of your application under
HP Caliper.
Metrics for Integrity Servers Itanium 2 Systems
The following CPU events are directly measured:
• IA64_INST_RETIRED — Number of retired IA-64 instructions. The count includes
all predicated on instructions and nops, but excludes hardware-inserted RSE
operations.
• NOPS_RETIRED — Number of retired nop.i, nop.m, or nop.b instructions. The
count excludes predicated off nop instructions.
• CPU_CYCLES — Number of elapsed processor cycles.
• BACK_END_BUBBLE.ALL — Number of cycles when the back end of the pipeline
was stalled.
• % of Cycles Lost Due to Stalls — Percentage of stall cycles with respect to total
number of elapsed cycles. This is calculated as the following: 100 *
BACK_END_BUBBLE.ALL / CPU_CYCLES.
• Effective CPI — Cycles per effective instruction, excluding nop instructions. This
is calculated as the following: CPU_CYCLES / (IA64_INST_RETIRED -
NOPS_RETIRED).
• Effective CPI During Unstalled Execution — Cycles per effective instruction,
excluding stall cycles and nop instructions. This is calculated as the following:
(CPU_CYCLES - BACK_END_BUBBLE.ALL) / (IA64_INST_RETIRED -
NOPS_RETIRED).
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