RMA: remove reference to MPI-2 RMA

[devreal]

Problem

The RMA chapter in the section on dynamic windows refers to all but the dynamic window creation functions as the MPI-2 RMA model:

12.2.4 Window of Dynamically Attached Memory The MPI-2 RMA model requires the user to identify the local memory that may be a target of RMA calls at the time the window is created. This has advantages for both the programmer (only this memory can be updated by one-sided operations and provides greater safety) and the MPI implementation (special steps may be taken to make onesided access to such memory more efficient). However, consider implementing a modifiable linked list using RMA operations; as new items are added to the list, memory must be allocated. In a C or C++ program, this memory is typically allocated using malloc or new respectively. In MPI-2 RMA, the programmer must create a window with a predefined amount of memory and then implement routines for allocating memory from within the window’s memory. In addition, there is no easy way to handle the situation where the predefined amount of memory turns out to be inadequate. To support this model, the routine MPI_WIN_CREATE_DYNAMIC creates a window that makes it possible to expose memory without remote synchronization. It must be used in combination with the local routines MPI_WIN_ATTACH and MPI_WIN_DETACH.

Proposal

The previously described window creation procedures require the user to identify the local memory that may be a target of RMA calls at the time the window is created. This has advantages for both the programmer (only this memory can be updated by one-sided operations and provides greater safety) and the MPI implementation (special steps may be taken to make onesided access to such memory more efficient). However, consider implementing a modifiable linked list using RMA operations; as new items are added to the list, memory must be allocated. In a C or C++ program, this memory is typically allocated using malloc or new respectively. With the previously described window creation procedures, the programmer must create a window with a predefined amount of memory and then implement routines for allocating memory from within the window’s memory. In addition, there is no easy way to handle the situation where the predefined amount of memory turns out to be inadequate. To support this model, the routine MPI_WIN_CREATE_DYNAMIC creates a window that makes it possible to expose memory without remote synchronization. It must be used in combination with the local routines MPI_WIN_ATTACH and MPI_WIN_DETACH.

Changes to the Text

See above

Impact on Implementations

None

Impact on Users

Forget about MPI-2

References and Pull Requests

TBD