[MPICH] Availability of the Driller library

[Darius Buntinas]

> 
>> Is there a way to split a vma and share only part of it?  That would 
>> be interesting as well.
> 
> Hmmm that would be possible, but the cost of sharing part or all of a 
> given memory region is roughly the same, so why would you want to do this?

Well I was thinking that in MPI, when a call to, say MPI_Send is made, 
the process is not allowed to access the buffer being sent until the 
call returns.  So, I was thinking that if the remapping were done in 
MPI_Send, then we wouldn't have to worry about other threads modifying 
the data.  That assumes, that the rest of the segment (not being 
remapped) would not have to be copied.

-d