[mpich-discuss] Is there only one ADIOI_xxx_OpenColl

[Rajeev Thakur]

See romio/adio/ad_nfs/ad_nfs_open.c and romio/adio/common/ad_opencoll_scalable.c . In general, do a recursive grep for Open in the adio directory and you will find all of them.


On Apr 24, 2012, at 3:57 AM, Ju JiaJia wrote:

> Hi all:
>    I'm runing MPI app on two nodes with MPICH2. But without NFS, I copy the app file in which calls MPI_File_open to open a file in the current dir to the same location on all the nodes.
> It failed in MPI_File_open when i run. I trace the code, It failed in MPI_File_open--->ADIO_Open----->ADIOI_OpenColl. ADIOI_OpenColl is a pointer to ADIOI_GEN_OpenColl.
> in which one process opens to create the file, all others open, by turning off ADIO_CREATE. So i understand why my app failed.
>  
> But in MPI_File_open, some comments like this:
>     /* actual opens start here */
>     /* generic open: one process opens to create the file, all others open */
>     /* nfs open: everybody opens or else you'll end up with "file not found"
>      * due to stupid nfs consistency semantics */
>     /* scalable open: one process opens and broadcasts results to everyone */
>     ADIOI_OpenColl(fd, rank, access_mode, error_code);
>  
> I searched all the source code and found  ADIOI_GEN_OpenColl only.
> So where is the other two open methods which mean nfs open and scalable open implemented?
> Does it mean i can only run MPI app in which calls MPI_File_open when all nodes can access the unique copy of the app file?
>  
> My Engllish is not good, i hope you can understand what i say.
>  
> Any explanation will be appreciated.
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