HP Caliper User's Guide

Table B-14 Information in dtlb Measurement Reports (continued)
DescriptionColumn
Percent of sampled data TLB misses that were handled by software for the given program
object.
% DTLB Soft
Fill
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 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 Data TLB Metrics Are Obtained
HP Caliper obtains L1 data TLB 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 data TLB metrics
are obtained from the PMU's data event address register (D-EAR).
HP Caliper takes samples every Nth data TLB miss, where N is defined in the dtlb
measurement configuration file in the HP Caliper home directory config subdirectory.
At each sample point, HP Caliper records both the instruction that resulted in an L1
data TLB miss and the level of the TLB hierarchy that satisfied the miss, L2 data TLB,
HPW, or software. 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
the extreme case of taking one sample for each TLB miss event, the kernel will trap on
every event, making the resulting data of limited value.
264 Descriptions of Measurement Reports