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Diffstat (limited to 'release_docs/RELEASE.txt')
-rw-r--r-- | release_docs/RELEASE.txt | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/release_docs/RELEASE.txt b/release_docs/RELEASE.txt index bba27c9..ece00cc 100644 --- a/release_docs/RELEASE.txt +++ b/release_docs/RELEASE.txt @@ -1083,6 +1083,27 @@ Bug Fixes since HDF5-1.12.0 release (DER - 2021/11/23, HDFFV-11286) + - Unified handling of collective metadata reads to correctly fix old bugs + + Due to MPI-related issues occurring in HDF5 from mismanagement of the + status of collective metadata reads, they were forced to be disabled + during chunked dataset raw data I/O in the HDF5 1.10.5 release. This + wouldn't generally have affected application performance because HDF5 + already disables collective metadata reads during chunk lookup, since + it is generally unlikely that the same chunks will be read by all MPI + ranks in the I/O operation. However, this was only a partial solution + that wasn't granular enough. + + This change now unifies the handling of the file-global flag and the + API context-level flag for collective metadata reads in order to + simplify querying of the true status of collective metadata reads. Thus, + collective metadata reads are once again enabled for chunked dataset + raw data I/O, but manually controlled at places where some processing + occurs on MPI rank 0 only and would cause issues when collective + metadata reads are enabled. + + (JTH - 2021/11/16, HDFFV-10501/HDFFV-10562) + - Fixed several potential MPI deadlocks in library failure conditions In the parallel library, there were several places where MPI rank 0 |