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| author | Mike McGreevy <mamcgree@hdfgroup.org> | 2011-10-05 22:00:35 (GMT) |
|---|---|---|
| committer | Mike McGreevy <mamcgree@hdfgroup.org> | 2011-10-05 22:00:35 (GMT) |
| commit | d3b7ce468989bea9ef4e8f78e53b52b2ae766da3 (patch) | |
| tree | c2a88d0f4d9a211f22df18842815ef8fac0fa8a5 /release_docs | |
| parent | 3389fa88ee3b63f4eb8c8887f8411cc37ec86c2f (diff) | |
| download | hdf5-d3b7ce468989bea9ef4e8f78e53b52b2ae766da3.zip hdf5-d3b7ce468989bea9ef4e8f78e53b52b2ae766da3.tar.gz hdf5-d3b7ce468989bea9ef4e8f78e53b52b2ae766da3.tar.bz2 | |
[svn-r21479] Merge revision 21101 from trunk to 1.8 branch:
HDFFV-7639
Purpose:
Remove H5_MPI_SPECIAL_COLLECTIVE_IO_WORKS and
H5_MPI_COMPLEX_DERIVED_DATATYPE_WORKS #defines from source.
Description:
Two advanced parallel functionalities, special collective IO and
complex derived datatypes, are not supported by older
implementations of mpi, and thus our code limits the use of these
features with #ifdefs and has checks in configure to set them (or
not). Unfortunately, configure can't actually run a parallel check
to see if these features are working (nor not) so it resorts to
looking in the config files where they are explicity enabled or
disabled based on versions of mpi, sytems being built on, or for
no documented reason at all (i.e. just set to on or off as some
'default'). Overriding these settings is easy if need be, provided
it is known that it needs to be done to get improved performance,
and oftentimes it is not.
Most new MPI implementations successfully handle the functionality
requested when these #defines are set, and many of the "turn these
features off" cases in the config files are for old (> 5 years)
versions of MPI and retired systems (such as NCSA's tungsten).
Therefore, the decision has been made to remove the support for
these old versions of MPI and systems that cannot handle these
behaviors. The #ifdefs and supporting setup in the config/ files
and configure script has been removed, and the code executed when
these options were not set removed from the source.
In passing, this commit also cleans up some whitespace issues in
both t_mpi.c and H5Dmpio.c. Furthermore, in t_mpi.c, the special
collective IO test was not getting regularly run due to it being
written to work only with four processes (we regularly test with
six, previously with three), and thus it failed when actually run
due to an out of bounds data buffer assignment. It has been
modified to run at any number of processes greater than four, and
the memory problem has been fixed so the test passes.
Tested:
Jam, h5committest, Ember
Diffstat (limited to 'release_docs')
| -rw-r--r-- | release_docs/RELEASE.txt | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/release_docs/RELEASE.txt b/release_docs/RELEASE.txt index 3d25b38..82f76e3 100644 --- a/release_docs/RELEASE.txt +++ b/release_docs/RELEASE.txt @@ -150,7 +150,12 @@ Bug Fixes since HDF5-1.8.7 Parallel Library ---------------- - - None + - Special Collective IO (IO when some processes do not contribute to the + IO) and Complex Derived Datatype MPI functionalities are no longer + conditionally enabled in the library by configure. They are always + enabled in order to take advantage of performance boosts from these + behaviors. Older MPI implementations that do not allow for these + functionalities can no longer by used by HDF5. (MAM - 2011/07/08). Tools ----- |