[mpich-discuss] MPI_File_set_view Error: ADIOI_Count_contiguous_blocks

[Robert Latham]

On Fri, May 30, 2008 at 12:56:41PM +0200, Ingo Bojak wrote:
> One more question perhaps: The file is being only written to by all  
> ranks (no read), in sequential order (one window after the other, with  
> each rank writing to different parts of one window via the fileview) and  
> collectively (MPI_File_write_all). I know how much each process writes  
> every time (as is specified also by the fileview). I wonder if it is  
> then advantageous to provide hints with INFO? I'm particularly thinking  
> of "collective_buffering", but I do not quite understand what values the  
> different "cb" variables would have to be set to...

Hi Ingo.  

We'll need a lot of information before we can advise you on hints.
- How many processes are writing?
- About how much data is each process writing?
- Is the data noncontiguous in memory? file? both?
- What's the interconnect for this machine?
- How fast is your storage?

Thanks
==rob

-- 
Rob Latham
Mathematics and Computer Science Division    A215 0178 EA2D B059 8CDF
Argonne National Lab, IL USA                 B29D F333 664A 4280 315B