Hi all, On Mar 4, 2011, at 2:22 PM, Rob Latham wrote:
> On Fri, Mar 04, 2011 at 10:09:14AM -0500, Mark Howison wrote: >> Hi Matthieu, >> >> The Integrated Performance Monitor (IPM) v2 beta has a POSIX I/O >> tracing feature. This will give you detailed output of the underlying >> POSIX calls (such as open, write and read) made by your application >> (through the pHDF layer). You can download it here: >> >> http://tools.pub.lab.nm.ifi.lmu.de/web/ipm/ >> >> To enable I/O tracing, you have to configure with >> >> ./configure --enable-posixio CFLAGS=-DHAVE_POSIXIO_TRACE >> >> You have to relink your application against the libipm.a that his >> produces (or you can enable the shared library and do an LD_PRELOAD). >> After you application runs, you'll have a text file for each MPI rank >> with the POSIX calls and their arguments. > > Matthieu Dorier was asking for a tuple of (rank,file,offset,size). > > I guess this really belongs on the ipm-hpc-help list, but IPM doesn't > actually give you the offset information. It wraps fseek(3) but HDF5 > using MPI-IO is probably going to call lseek(2), lseek64(2) some other > seek-like system call. > > IPM is pretty close, giving the file, size, and a timestamp all tucked > into a file-per-rank. We've got a small project currently in the works that gives a minimal amount of information back to the application: whether a collective I/O write/read operation completed as a collective, or was broken down into an independent operation (or some combination of those two, for chunked datasets); which should help some. I don't think we've got direct funding for more effort in this direction currently, but I'd sure like to roll it into a new set of funding (or work with someone who feels like submitting a patch for this idea). Quincey _______________________________________________ Hdf-forum is for HDF software users discussion. [email protected] http://mail.hdfgroup.org/mailman/listinfo/hdf-forum_hdfgroup.org
