Re: [boost] [BGL] Trying to get a correclty working Parallel BFS code

Subject: Re: [boost] [BGL] Trying to get a correclty working Parallel BFS code
From: Jeremiah Willcock (jewillco_at_[hidden])
Date: 2009-10-27 02:29:17

On Mon, 26 Oct 2009, Sandeep Gupta wrote:

> Hi All,
>  I  have spent significant effort on parallel bfs. Currently its almost
> working. I would really appreciate some help to get it running correctly. I
> have attached the code (self contained and requires no input file).
> I think I have followed all the guidelines regarding distributed property
> maps mentioned in the docs (
> http://www.osl.iu.edu/research/pbgl/documentation/graph/breadth_first_search.html
> ).
> I am out of ideas of where things can could have gone wrong.

The graph is distributed by source vertex across all processors, and so 
you need to add them on every processor (or at least on the processor that 
owns them, which is probably not processor 0).  Thus, your graph is 
missing whichever edges would be on processor 1, leading to incorrect 
results.  Try adding all of the edges on all processors and see if this 
fixes your problem.

-- Jeremiah Willcock