On Nov 17, 2010, at 6:58 AM, Ricardo Reis wrote:
> Thanks for the explanation. Then this should be updated in the spec no...?
You have no idea. :-)
The MPI Forum has been debating about exactly this issue for over a year. It
turns out to be a surprisingly complex, subtle issue (i.e., it's
Ricardo Reis wrote:
On Wed, 17 Nov 2010, Gus Correa wrote:
For what is worth, the MPI addresses (a.k.a. pointers)
in the Fortran bindings are integers, of standard size 4 bytes, IIRR.
Take a look at mpif.h, mpi.h and their cousins to make sure.
Unlike the Fortran FFTW "plans", you don't
On Wed, 17 Nov 2010, Gus Correa wrote:
For what is worth, the MPI addresses (a.k.a. pointers)
in the Fortran bindings are integers, of standard size 4 bytes, IIRR.
Take a look at mpif.h, mpi.h and their cousins to make sure.
Unlike the Fortran FFTW "plans", you don't declare MPI addresses as
Ricardo Reis wrote:
On Wed, 17 Nov 2010, Pascal Deveze wrote:
I think the limit for a write (and also for a read) is 2^31-1 (2G-1).
In a C program, after this value, an integer becomes negative. I
suppose this is also true in
Fortran. The solution, is to make a loop of writes (reads) of no
On Wed, 17 Nov 2010, Pascal Deveze wrote:
This is due to the interface defined for MPI_File_write that specifies an
integer for the length. The positive value of an integer are coded
in hexadecimal from to 7FFF FFF and negative values are coded from
8000 to .
(7FFF
This is due to the interface defined for MPI_File_write that specifies
an integer for the length. The positive value of an integer are coded
in hexadecimal from to 7FFF FFF and negative values are coded
from 8000 to .
(7FFF is exactly 2^31-1).
Pascal
Ricardo Reis
On Tue, 16 Nov 2010, Gus Correa wrote:
Ricardo Reis wrote:
and sorry to be such a nuisance...
but any motive for an MPI-IO "wall" between the 2.0 and 2.1 Gb?
Salve Ricardo Reis!
Is this "wall" perhaps the 2GB Linux file size limit on 32-bit systems?
No. This is a 64bit machine and if
Ricardo Reis wrote:
and sorry to be such a nuisance...
but any motive for an MPI-IO "wall" between the 2.0 and 2.1 Gb?
Salve Ricardo Reis!
Is this "wall" perhaps the 2GB Linux file size limit on 32-bit systems?
Gus
(1 mpi process)
best,
Ricardo Reis
'Non Serviam'
PhD candidate
and sorry to be such a nuisance...
but any motive for an MPI-IO "wall" between the 2.0 and 2.1 Gb?
(1 mpi process)
best,
Ricardo Reis
'Non Serviam'
PhD candidate @ Lasef
Computational Fluid Dynamics, High Performance Computing, Turbulence
http://www.lasef.ist.utl.pt
Cultural
