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

Table 9 Information in alat Measurement Reports
DescriptionColumn
Percent of the total for <metric> attributable to a given program object. The <metric> is the
same as the <metric> HP Caliper uses for sorting, except when the sort metric is address,
in which case sampled misses is used.
% Total Sampled ALAT
Misses
A running sum of the percent of total for <metric> accounted for by the given program object
and those listed above it.
Cumulat % of Total
Total number of sampled failed chk.a/ld.c instructions attributed to the given program
object.
Sampled ALAT Misses
Kernel Thread ID suffixed with the the name of the routine that the thread will execute once
it is created.
Kernel Thread
Identification Number
A shared library or the main executable.Load Module
Routine from your application.Function
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 ALAT Metrics Are Obtained
HP Caliper obtains ALAT metrics from the processor's performance monitoring unit (PMU).
Exact counts are obtained from the PMU's set of performance monitor configuration
(PMC)/performance monitor data (PMD) register pairs. Sampled ALAT metrics are obtained from
the PMU's data event address register (D-EAR).
HP Caliper takes samples every Nth recorded ALAT miss, where N is defined in the alat
measurement configuration file in the HP Caliper home directory config subdirectory. At each
sample point, HP Caliper records the instruction that resulted in an ALAT miss. You can override
the value in the measurement configuration file by using the -s option.
More frequent sampling increases HP Caliper's perturbation of your application. In particular,
taking a sample could cause some of the ALAT content to be replaced. If so, the following
chk.a/ld.c instructions are more likely to fail, making the resulting data of limited value.
branch Measurement Report Description
With the branch measurement, produced by the branch measurement configuration file, HP
Caliper measures and reports two levels of information:
• Exact counts of branch prediction metrics summed across the entire run of an application
• Sampled branch prediction metrics that are associated with particular locations in the
application
The report shows measured data by thread, load module, function, statement, instruction bundle,
and instruction.
branch Measurement Report Description 171