On Wed, 30 Jul 2003, choy hau yan wrote:
> can we call distributed memory? because it also got 2 processors share
> the same memory but they also connecting with another CPU.
Yes, but only the MPI layer knows that. Your processes act as if they
have completely separate memory spaces. You still use MPI_SEND/MPI_RECV
to move data around, it just happens to use shared memory instead of a
network.
> If master sending small value array,all the data is correct. if sending
> big array, it got problem. Is that posible use some command do the clear
> off in buffer before use another mpi_send.
It's probably easiest to just execute a do loop over the array and set all
the values to a specific sentinel value. This is, obviously, not good for
performance, but it's just for debugging.
> (I used many mpi_send in one time).
I'm not sure what you mean here -- are you writing a multi-threaded
program?
> Is that posible some data lost or change when sending big data form one
> processors to another ? this happen because of data lost in network wire
> while transfering.
LAM is using TCP between your processes, which is a reliable transport
mechanism. This should not happen without some kind of detectable error.
--
{+} Jeff Squyres
{+} jsquyres_at_[hidden]
{+} http://www.lam-mpi.org/
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