HP Caliper 5.3 User Guide (5900-1558, February 2011)

Table 34 Information in traps Measurement Reports (continued)
DescriptionColumn
Source file associated with a function.File
The column contains one of these:
• 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.
Line |
Slot |
Col,Offset
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 traps Metrics Are Obtained
HP Caliper obtains traps metrics using the execution trace buffer (ETB) of the performance
monitoring unit (PMU). The ETB is configured to capture all changes to/from privilege level 0.
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 traps 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.
HP Caliper attributes a sample to a trap by checking which offset into the interruption vector table
(IVT) the target branches to. HP Caliper gets the IVT start address from perfmon on HP-UX and
by reading kallsyms on Linux.
218 Descriptions of Measurement Reports