[MPI3-IO] Non blocking collective I/O ticket

[Rajeev Thakur]

> All input arguments
> should not be modified, and all output buffers should not be accessed before
> the completion call. 

Instead of all input arguments, I would just say input buffers since there are no other array arguments and datatypes are refcounted. So the sentence could say

"Input buffers should not be modified and output buffers should not be accessed before the completion call."

I was wondering if there is a way to forward reference this section somewhere earlier since it appears so late in the chapter.

I also noticed that ln 2-3 on pg 446 needs to be marked as a change in MPI-3 (color).

Rajeev



On Dec 14, 2011, at 10:17 AM, Mohamad Chaarawi wrote:

> I updated the draft and attached it to the ticket with Fab's comments, which included moving the entire split collective section to the deprecated chapter, and emphasizing more the progress rules.
> 
> I would like to get some feedback especially on the nonblocking Collective I/O section on page 484, which I updated to emphasize the progress rules which wasn't very clear in the first draft.
> 
> Right now it reads as:
> 
> \subsection{Nonblocking Collective File Operations}
> %--------------------------------------                                                                                                                                                               ;              
> \label{sec:io-semantics-nb-collective}
> Nonblocking collective file operations are subject to the same restrictions as
> blocking collective I/O operations. All processes, belonging to the
> communicator that was used to open the file, must call collective I/O
> operations (blocking and nonblocking) in the same order. In particular, once a
> process calls a collective I/O operation, all other processes, belonging to
> the communicator used to open the file, must eventually call the same
> collective I/O operation, and no other collective I/O operation on the same
> file handle in between.
> 
> Nonblocking collective I/O operations do not match with blocking collective
> I/O operations. Multiple nonblocking collective I/O operations can be
> outstanding on a single file handle.  Quality MPI implementations should be
> able to support a large number of pending nonblocking I/O operations.
> 
> All calls are local and return immediately, irrespective of the status of
> other processes. The call initiates the operation which may progress
> independently of any communication, computation, or I/O. The call returns a
> request handle, which must be passed to a completion call. All input arguments
> should not be modified, and all output buffers should not be accessed before
> the completion call. The same progress rules described for nonblocking
> collective operations apply for nonblocking collective I/O operations. For a
> complete discussion, please refer to the semantics set forth in
> Section~\ref{sec:nbcoll} on page~\pageref{sec:nbcoll}.
> 
> 
> Thanks,
> Mohamad
> 
> On 12/13/2011 04:49 PM, Mohamad Chaarawi wrote:
>> Hi All, 
>> 
>> I think enough people have joined to post to this list now.. 
>> Quincey will present ticket 273 (immediate non-blocking collective I/O operations) for a first reading at the January meeting. I attached an updated draft for IO chapter authors (or others) to review before sending it out on the general mailing list. 
>> Last time there was an issue with deprecating the split collective routines. Let me know if you have any comments. 
>> 
>> ticket url: 
>> https://svn.mpi-forum.org/trac/mpi-forum-web/ticket/273 
>> 
>> Thanks, 
>> Mohamad 
>> 
>> 
>> 
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