HP Caliper User Guide Release 5.5 (5900-2351, August 2012)

cycles Measurement Metrics
See Table 20 (page 190).
In this table, “program object” refers to any of the following:
• Thread
• Load module
• Function
• Source statement
• Instruction bundle
Table 20 Information in cycles Measurement Reports
DescriptionColumn
Percent of the total IP samples attributable to a given program object.% Total IP Samples
(ETB)
Running sum of the percent of total IP samples accounted for by the given program object and
those listed above it.
Cumulat % of Total
Total number of IP samples attributed to the given program object.IP Samples (ETB)
Kernel Thread ID suffixed with the the name of the routine that the thread will execute once it
is created.
Kernel Thread
Identification Number
Shared library or the main executable.Load Module
Routine from your application.Function
Source file associated with a function.File
The average number of cycles elapsed to retire the bundle. If there are no stalls, it should take
exactly one cycle to retire a bundle. If the Cycles Per Bundle information is more than 1, this
means that many additional cycles of stall were seen on that bundle.
Cycles Per Bundle
If the Cycles per Bundle information is prefixed with an asterisk (*), that means that instructions
from that bundle are split issued.
The column contains one of these:Line |
Slot |
Col,Offset
• A source-code line number for rows showing statements
• An instruction slot number for rows showing instructions not on a bundle boundary
• A source-code column number followed by an offset from the beginning address of a function
for rows showing instructions on a bundle boundary
Column and line numbers are preceded by “~” when they are approximate due to optimization.
The column contains either a source statement preceded by “>” or a disassembled instruction.
Statements that are out of order due to optimization are preceded by “*>”.
>Statement |
Instruction
How cycles Metrics Are Obtained
HP Caliper obtains cycles metrics using the execution trace buffer (ETB) of the performance
monitoring unit (PMU). The ETB is configured to capture IPs of retired instructions. When a bundle
is retired, the IP address and the number of elapsed cycles to retire the bundle are recorded in the
ETB. The dual-core Itanium 2 and Itanium 9300 quad-core processor ETB is a circular buffer and
can contain up to 16 entries.
HP Caliper takes samples by using the overflow of one of the PMU's event counters as a sampling
trigger. Samples are taken every Nth PMU event, where both N and the sampling event are defined
in the cycles measurement configuration file in the HP Caliper home directory in the config
subdirectory. You can override the value in the measurement configuration file by using the -s
option.
190 Descriptions of Measurement Reports