Newsgroups: comp.parallel.mpi
From: prakash@cs.ucla.edu (Sundeep Prakash)
Subject: MPI on IBM-SP2 question
Organization: UCLA Computer Science Dept.
Date: 12 Jul 1996 19:51:40 GMT
Message-ID: <4s6acc$f0b@delphi.cs.ucla.edu>

  Hello,
   What is the size of the default buffer used for "MPI_Bsend"ing
 messages in the MPI implementation on the IBM-SP? I know that users
 can attach their own buffers using MPI_Buffer_attach, but if there
 isnt any such call in the user program, what (if any) buffer is used 
 and how large is it? Also,
 at what point does MPI_Send switch from MPI_Bsend to MPI_Ssend
 (I suspect the condition is (msg size > 5K || default buffer overflow))?
 Is this correct? I probably could find these details through experimentation,
 but I'm hoping someone can save me the trouble. You could send me email
 instead of replying to the post.

 Thanks very much in advance,

 Sundeep Prakash
 (prakash@cs.ucla.edu)

