HP Caliper User's Guide

4.84 85.02 4 42 10.5 25 50 25 0 0 0 0 0
libc.so.1::_arena_rmutex
4.72 89.75 5 41 8.2 40 60 0 0 0 0 0 0 Process Data Region
The Data Entry column shows the global variable name, process region name, or
unknown data address.
The process regions are:
• Process Text Region - the address space occupied by the process text/instructions
• Process Data Region - the address space occupied by initialized data and
uninitialized data (.bss)
• Heap - the address space where dynamically allocated memory resides
• Data and Heap combined - when HP Caliper cannot discover the data and heap
regions separately
• Process Stack Region - the user stack area
• Shared mem - all the shared memory areas mapped to the process
• RSE Stack - the RSE stack area
• Memory mapped shared library - the data area of the shared libraries mapped to
the process
• Memory mapped region - all other memory mapped regions
If there is more than one region of the same type, they are combined and reported as
a single entry.
The Data Summary report is generated per-process. For a per-thread report, use the
--thread all option. For a per-module report, use the --per-module-data True
option.
The Data Summary report can be merged or differenced across two databases that
contain the Data Summary information.
If a process exec()s, HP Caliper does not discover the process regions. In this case,
the data addresses are mapped to global variables, and any unassigned samples are
reported as unknown samples. A diagnostics message is generated with the report.
How Data Cache Metrics Are Obtained
HP Caliper obtains data cache 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 cache metrics
are obtained from the PMU's data event address register (D-EAR). Both sets of metrics
focus on the L1 cache, with notable exceptions.
HP Caliper takes samples every Nth data cache miss, where N is defined in the dcache
measurement configuration file in the HP Caliper home directory config subdirectory.
At each sample point, HP Caliper records both the instruction that resulted in a data
cache miss and the latency (number of clock cycles) incurred by the miss. You can
override the value in the measurement configuration file by using the -s option.
For data cache miss sampling, the PMU can monitor only one data cache load at a time.
Since there are likely to be multiple loads in progress at any given moment, the PMU
dcache Measurement Report Description 257