Edgar, Thanks - this is exactly what I was looking for. I started going through the code in earnest and trying to figure out exactly where the magic happens. I may have more questions :-)
Ognen Gabriel, Edgar via users writes: > the ompio software infrastructure has multiple frameworks. > > fs framework: abstracts out file system level operations (open, close, etc) > > fbtl framework: provides the abstractions and implementations of *individual* > file I/O operations (seek,read,write, iread,iwrite) > > fcoll framework: provides the abstractions and implementations of > *collective* file I/O operations ( read_all, write_all, etc.) > > sharedfp framework: provides the abstractions and implementations *shared > file pointer* file I/O operations (read_shared, write_shared, read_ordered, > write_ordered). > > Feel free to ping me also directly if you need more assistance. If you are > looking for a reference and more explanations, please have a look at the > following paper: > > Mohamad Chaarawi, Edgar Gabriel, Rainer Keller, Richard Graham, George > Bosilca and Jack Dongarra, 'OMPIO: A Modular Software Architecture for MPI > I/O', in Y. Cotronis, A. Danalis, D. Nikolopoulos, J. Dongarra, (Eds.) > 'Recent Advances in Message Passing Interface', LNCS vol. 6960, pp. 81-89, > Springer, 2011. > > http://www2.cs.uh.edu/~gabriel/publications/EuroMPI11_OMPIO.pdf > > Best regards > Edgar > > -----Original Message----- > From: users <users-boun...@lists.open-mpi.org> On Behalf Of Ognen Duzlevski > via users > Sent: Monday, November 2, 2020 7:54 AM > To: Open MPI Users <users@lists.open-mpi.org> > Cc: Ognen Duzlevski <mak...@sdf.org> > Subject: Re: [OMPI users] ompe support for filesystems > > Gilles, > > Thank you for replying. > > I took a look at the code and am curious to understand where the actual > read/write/seek etc. operations are implemented. From what I can > see/understand - what you pointed me to implements file open/close etc. > operations that pertain to particular filesystems. > > I then tried to figure out the read/write/seek etc. operations and can see > that a MPI_File structure appears to have a f_io_selected_module member, > whose v_2_0_0 member seems to have the list of pointers to all the > functionals dealing with the actual file write/read/seek functionality. Is > this correct? > > What I would like to figure out is where the actual writes or reads happen > (as in the underlying filesystem's implementations). I imagine for some > filesystems a write, for example, is not just a simple call to the write onto > disk but involves a bit more logic/magic. > > Thanks! > Ognen > > > Gilles Gouaillardet via users writes: > >> Hi Ognen, >> >> MPI-IO is implemented by two components: >> - ROMIO (from MPICH) >> - ompio ("native" Open MPI MPI-IO, default component unless running >> on Lustre) >> >> Assuming you want to add support for a new filesystem in ompio, first >> step is to implement a new component in the fs framework the framework >> is in /ompi/mca/fs, and each component is in its own directory (for >> example ompi/mca/fs/gpfs) >> >> There are a some configury tricks (create a configure.m4, add Makefile >> to autoconf, ...) to make sure your component is even compiled. >> If you are struggling with these, feel free to open a Pull Request to >> get some help fixing the missing bits. >> >> Cheers, >> >> Gilles >> >> On Sun, Nov 1, 2020 at 12:18 PM Ognen Duzlevski via users >> <users@lists.open-mpi.org> wrote: >>> >>> Hello! >>> >>> If I wanted to support a specific filesystem in open mpi, how is this >>> done? What code in the source tree does it? >>> >>> Thanks! >>> Ognen
