package. A number of filesets that have been
collected into a single installable image of program
products, or LPPs. Multiple filesets can be bundled
together for installing groups of software together. See
also
fileset
and
Licensed Program Product
.
parallelism. The degree to which parts of a program
may be concurrently executed.
parallelize. To convert a serial program for parallel
execution.
Parallel Operating Environment (POE). An execution
environment that smooths the differences between
serial and parallel execution. It lets you submit and
manage parallel jobs. It is abbreviated and commonly
known as POE.
parameter. * (1) In Fortran, a symbol that is given a
constant value for a specified application. (2) An item in
a menu for which the operator specifies a value or for
which the system provides a value when the menu is
interpreted. (3) A name in a procedure that is used to
refer to an argument that is passed to the procedure.
(4) A particular piece of information that a system or
application program needs to process a request.
partition. (1) A fixed-size division of storage. (2) In
terms of the IBM RS/6000 SP, a logical definition of
nodes to be viewed as one system or domain. System
partitioning is a method of organizing the SP into
groups of nodes for testing or running different levels of
software of product environments.
Partition Manager. The component of the Parallel
Operating Environment (POE) that allocates nodes, sets
up the execution environment for remote tasks, and
manages distribution or collection of standard input
(STDIN), standard output (STDOUT), and standard
error (STDERR).
pdbx. pdbx is the parallel, symbolic command line
debugging facility of PE. pdbx is based on the dbx
debugger and has a similar interface.
PE. The IBM Parallel Environment for AIX program
product.
performance monitor. A utility which displays how
effectively a system is being used by programs.
POE. See Parallel Operating Environment.
pool. Groups of nodes on an SP that are known to the
Resource Manager, and are identified by a number.
point-to-point communication. A communication
operation which involves exactly two processes or
tasks. One process initiates the communication through
a
send
operation. The partner process issues a
receive
operation to accept the data being sent.
procedure. (1) In a programming language, a block,
with or without formal parameters, whose execution is
invoked by means of a procedure call. (2) A set of
related control statements that cause one or more
programs to be performed.
process. A program or command that is actually
running the computer. It consists of a loaded version of
the executable file, its data, its stack, and its kernel data
structures that represent the process's state within a
multitasking environment. The executable file contains
the machine instructions (and any calls to shared
objects) that will be executed by the hardware. A
process can contain multiple threads of execution.
The process is created via a fork() system call and
ends using an exit() system call. Between fork and
exit, the process is known to the system by a unique
process identifier (pid).
Each process has its own virtual memory space and
cannot access another process's memory directly.
Communication methods across processes include
pipes, sockets, shared memory, and message passing.
prof. A utility which produces an execution profile of
an application or program. It is useful to identifying
which routines use the most CPU time. See the man
page for prof.
profiling. The act of determining how much CPU time
is used by each function or subroutine in a program.
The histogram or table produced is called the execution
profile.
Program Marker Array. An X-Windows run time
monitor tool provided with Parallel Operating
Environment, used to provide immediate visual
feedback on a program's execution.
pthread. A thread that conforms to the POSIX
Threads Programming Model.
Rreduction operation. An operation, usually
mathematical, which reduces a collection of data by one
or more dimensions. For example, the arithmetic SUM
operation is a reduction operation which reduces an
array to a scalar value. Other reduction operations
include MAXVAL and MINVAL.
remote host. Any host on a network except the one at
which a particular operator is working.
192 IBM PE for AIX V2R4.0: Messages