Hi John, On Thu, Apr 3, 2014 at 6:36 AM, Biddiscombe, John A. <[email protected]> wrote: > Greetings > > > > I've been forwarded some info regarding a hang on hdf5 read from a user of > enzo. > > The problem appears when 512 (or more) processes open a file in serial and > each independently read a hyperslab (non overlapping, I believe, but this > may not be correct).
Looking at the stack trace, this is indeed a set of non-overlapping hyperslabs, as it occurs during what Enzo refers to as ParallelRootGridIO. > > I asked for a stack trace and the attached screenshot was sent to me. > > > > My advice to them was to open the file in parallel using the mpio driver > rather than in serial and the problem with probably go away. I suspect this would probably require a rather large and somewhat invasive change to the Enzo codebase, particularly as there are incompatibilities with MPI-enabled HDF5 in other areas of Enzo. -Matt > > But I'd like to ask if from the stacktrace you can tell if this is a known > bug? > > The problem occurs with 1.8.12 and 1.9.something > > > > thanks > > > > JB > > > > -- > > John Biddiscombe, email:biddisco @.at.@ cscs.ch > > http://www.cscs.ch/ > > CSCS, Swiss National Supercomputing Centre | Tel: +41 (91) 610.82.07 > > Via Trevano 131, 6900 Lugano, Switzerland | Fax: +41 (91) 610.82.82 > > > > > _______________________________________________ > Hdf-forum is for HDF software users discussion. > [email protected] > http://mail.lists.hdfgroup.org/mailman/listinfo/hdf-forum_lists.hdfgroup.org > _______________________________________________ Hdf-forum is for HDF software users discussion. [email protected] http://mail.lists.hdfgroup.org/mailman/listinfo/hdf-forum_lists.hdfgroup.org
