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Subject: Re: [OMPI users] Problem with MPI_BARRIER
From: Rolf Riesen (rolf.riesen_at_[hidden])
Date: 2011-09-08 10:01:37


On Thu Sep 8, 2011 15:41:57, Ghislain Lartigue wrote:
> Ghislain These "times" have no units, it's just an example...
> Ghislain Whatever units are used, at least one process should spend a very small of time in the barrier (compared to the other processes) and this is not what I see in my code.

You seem to assume the last process to enter the barrier will be the
first process to leave the barrier. That may or may not be the case,
depending on the barrier algorithm in use.

Rolf

+++-+--+----+-------+------------+--------------------+------------------------
Rolf Riesen, Ph.D. Email: rolf.riesen_at_[hidden]
Senior Research Scientist Phone: +353 1 826-9161
IBM Research, Ireland WWW: http://bit.ly/rolfIBM
Mulhuddart, Dublin 15