[mpich-discuss] messages queue

[Rajeev Thakur]

A queue of 100 messages of 100 bytes is not too big. What happens if you
replace MPI_Send with MPI_Isend? Can you send us a small test program?

Rajeev
 

> -----Original Message-----
> From: owner-mpich-discuss at mcs.anl.gov 
> [mailto:owner-mpich-discuss at mcs.anl.gov] On Behalf Of Jaroslaw Bulat
> Sent: Thursday, July 03, 2008 7:57 AM
> To: mpich2
> Subject: [mpich-discuss] messages queue
> 
> Hi All!
> 
> I found the following problem using MPICH2 (1.0.6 and 1.0.7 with sock
> and nemesis channel). There are 5 unique process which interchange
> messages by means of MPI_Send() and MPI_Irecv() + MPI_Waitany() or
> MPI_Testany(). Since the MPI_Send() doesn't wait until 
> receiver receive
> message and process it, it is possible to see a queue of messages
> waiting for processing at the receiver.  In such a situation my sender
> proces is crashing during calling MPI_Send() function.  Queue of
> unprocessed messages is of the length of ~100 messages of the 
> length 100
> Bytes each.
> I cannot use MPI_Ssend() which resolve this problem because 
> in this way
> my system is less responsive.
> 
> How can I control length of queue? 
> Is it possible to allocate more memory for internal MPI buffer? 
> 
> 
> Regards,
> Jarek!
> 
> 
> 
>