On Sep 18, 2014, at 2:43 AM, XingFENG <xingf...@cse.unsw.edu.au> wrote:
> a. How to get more information about errors? I got errors like below. This > says that program exited abnormally in function MPI_Test(). But is there a > way to know more about the error? > > *** An error occurred in MPI_Test > *** on communicator MPI_COMM_WORLD > *** MPI_ERR_TRUNCATE: message truncated > *** MPI_ERRORS_ARE_FATAL: your MPI job will now abort For the purpose of this discussion, let's take a simplification that you are sending and receiving the same datatypes (e.g., you're sending MPI_INT and you're receiving MPI_INT). This error means that you tried to receive message with too small a buffer. Specifically, MPI says that if you send a message that is X element long (e.g., 20 MPI_INTs), then the matching receive must be Y elements, where Y>=X (e.g., *at least* 20 MPI_INTs). If the receiver provides a Y where Y<X, this is a truncation error. Unfortunately, Open MPI doesn't report a whole lot more information about these kinds of errors than what you're seeing, sorry. > b. Are there anything to note about asynchronous communication? I use > MPI_Isend, MPI_Irecv, MPI_Test to implement asynchronous communication. My > program works well on small data sets(10K nodes graphs), but it exits > abnormally on large data set (1M nodes graphs). Is it failing due to truncation errors, or something else? -- Jeff Squyres jsquy...@cisco.com For corporate legal information go to: http://www.cisco.com/web/about/doing_business/legal/cri/
