HP-MPI User's Guide (11th Edition)

Glossary
derived data types
Glossary312
derived data types User-defined
structures that specify a sequence of basic
data types and integer displacements for
noncontiguous data. You create derived data
types through the use of type-constructor
functions that describe the layout of sets of
primitive types in memory. Derived types
may contain arrays as well as combinations
of other primitive data types.
determinism A behavior describing
repeatability in observed parameters. The
order of a set of events does not vary from
run to run.
domain decomposition Breaking down an
MPI application’s computational space into
regular data structures such that all
computation on these structures is identical
and performed in parallel.
executable A binary file containing a
program (in machine language) which is
ready to be executed (run).
explicit parallelism Programming style
that requires you to specify parallel
constructs directly. Using the MPI library is
an example of explicit parallelism.
functional decomposition Breaking down
an MPI application’s computational space
into separate tasks such that all
computation on these tasks is performed in
parallel.
gather Many-to-one collective operation
where each process (including the root)
sends the contents of its send buffer to the
root.
granularity Measure of the work done
between synchronization points.
Fine-grained applications focus on execution
at the instruction level of a program. Such
applications are load balanced but suffer
from a low computation/communication
ratio. Coarse-grained applications focus on
execution at the program level where
multiple programs may be executed in
parallel.
group Set of tasks that can be used to
organize MPI applications. Multiple groups
are useful for solving problems in linear
algebra and domain decomposition.
intercommunicators Communicators that
allow only processes in two different groups
to exchange data.
intracommunicators Communicators that
allow processes within the same group to
exchange data.
instrumentation Cumulative statistical
information collected and stored in ASCII
format. Instrumentation is the
recommended method for collecting profiling
data.
latency Time between the initiation of the
data transfer in the sending process and the
arrival of the first byte in the receiving
process.
load balancing Measure of how evenly the
work load is distributed among an
application’s processes. When an application
is perfectly balanced, all processes share the
total work load and complete at the same
time.
locality Degree to which computations
performed by a processor depend only upon
local data. Locality is measured in several
ways including the ratio of local to nonlocal
data accesses.