Rob,
Thanks for sharing your "jumpshot" experiment for demonstrating my point of
view
I really appreciate the result !
Pascal
De :Rob Latham
A : Open MPI Users
Date : 05/07/2011 17:34
Objet : Re: [OMPI users] File seeking with shared filepointer issues
On Mon, Jun 27, 2011 at 03:20:36PM +0200, pascal.dev...@bull.net wrote:
>
> Christian,
>
> Suppose you have N processes calling the first MPI_File_get_position_shared
> ().
>
> Some of them are running faster and could execute the call to
> MPI_File_seek_shared() before all the other have got th
, I do not have any real interest in the filesize
read this way.
Christian
<-Original Message->
>From: Rob Latham [r...@mcs.anl.gov]
>Sent: 7/1/2011 11:13:29 PM
>To: jsquy...@cisco.com
>Cc: us...@open-mpi.org
>Subject: Re: [OMPI users] File seeking with shared filepoi
On Sat, Jun 25, 2011 at 06:54:32AM -0400, Jeff Squyres wrote:
> Rob -- can you comment on this, perchance? Is this a bug in ROMIO, or if
> not, how is one supposed to use this interface can get consistent answers in
> all MPI processes?
Maybe the problem here is that shared file pointers were
On Sat, Jun 25, 2011 at 06:54:32AM -0400, Jeff Squyres wrote:
> I'm not super-familiar with the IO portions of MPI, but I think that you
> might be running afoul of the definition of "collective." "Collective," in
> MPI terms, does *not* mean "synchronize." It just means that all functions
> m
rg
>Subject: Re: [OMPI users] File seeking with shared filepointer issues
>
>Christian,
>
>Suppose you have N processes calling the first
MPI_File_get_position_shared
>().
>
>Some of them are running faster and could execute the call to
>MPI_File_seek_shared() before all the
ronize all
processes just before the call to MPI_File_seek_shared().
Pascal
users-boun...@open-mpi.org a écrit sur 25/06/2011 12:54:32 :
> De : Jeff Squyres
> A : Open MPI Users
> Date : 25/06/2011 12:55
> Objet : Re: [OMPI users] File seeking with shared filepointer issues
> Envoyé
I'm not super-familiar with the IO portions of MPI, but I think that you might
be running afoul of the definition of "collective." "Collective," in MPI
terms, does *not* mean "synchronize." It just means that all functions must
invoke it, potentially with the same (or similar) parameters.
Hen
I'm having some issues with MPI_File_seek_shared. Consider the following
small test C++ program
#include
#include
#define PATH "simdata.bin"
using namespace std;
int ThisTask;
int main(int argc, char *argv[])
{
MPI_Init(&argc,&argv); /* Initialize MPI */
MPI_Comm_rank(MPI_COMM_WORLD,&ThisT
