HP PAK Performance Analysis Tools User's Guide

40 Glossary
Glossary
Recursion collapsing A Puma
analysis mechanism for reporting
on the recursion of a program.
When you request recursion
collapsing, Puma may not make a
new node in a tree of call chains if
it encounters a recursive call
(depending on the type of recursion
collapsing you specify). Instead
Puma creates a recursive stub that
represents the recursion and refers
to the place higher up the call
chain where the same routine
occurs. Puma then jumps up in the
tree to that point and continues
playing out the stack trace.
Resources See Performance
statistics.
Sample The data obtained from
one interruption of an executing
program. The sample includes
statistical information and a stack
trace.
Sample interval The period of
time between samples taken
during data collection.
Samples per second The number
of samples Puma gathers per
second that a target program has
been allowed to run during data
collection.
Sibling A procedure with the
same parent as the given
procedure.
Stack Trace The sequence of
procedure calls leading to the
program counter at any given time.
Step To reconstruct the execution
of a program one sample at a time.
Target program A program from
which Puma collects performance
data.
Thread An independent stream
of program execution. A program
may be made up of one or more
threads; multiple threads in a
program cooperate in solving a
common problem.
Virtual CPU time The time the
processing unit spends in the
user's program, excluding time
spent waiting for I/O or executing
other programs.
Wall-clock time The total time
taken for program execution,
including disk and memory
accesses, I/O, and operating system
overhead.