Specifying nodes several times in the hostfile or with the --host
parameter seems to just add up the number of slots availible for the
given node. It doesn't seem to affect the mapping of the ranks. I think
this is due to how the hostfile is read into the structure that holds this
information in the source code.
Adding the host several times to the hostfile was the first thing I tried,
and I've also gotten that suggestion from others, so it might seem that it
would make sense to make it work that way.
I've hacked the source to be able to take a ranks-parameter in the
hostfile like this:
so I guess it's not a problem any more, but I would love to know if there
is a way of doing it without changing the source code.
You're very right about the unix scripting part. It makes sense to create
the hostfile this way.
On Mon, 1 Oct 2007, Christian Bell wrote:
> How about a hostfile such as
> % cat -n ~/tmp/hostfile
> 1 node0
> 2 node0
> 3 node1
> 4 node0
> 5 node1
> 6 node1
> Looks like the function to express the mapping is not anything simple. If it's
> an expressible function but too complicated for open mpi, you'll have to make
> your own script to generate the function. This shouldn't be hard to do with
> any standard unix scripting.
> . . christian
> On Mon, 01 Oct 2007, Torje Henriksen wrote:
>> Oh man, sorry about that, and thanks for the fast response.
>> Let me try again, please :)
>> I want to manually specify what ranks should run on what node.
>> Here is an example of a mapping that I can't seem to be able to do, since
>> it isn't a round-robin type of mapping.
>> hosts ranks
>> node0 0,1,3
>> node1 2,4,5
>> No matter what I do, I either get
>> node0: 0,1,2
>> node1: 3,4,5
>> node0: 0,2,4
>> node1: 1,3,5
>> Hope I got it right this time, and thank you again.
>> On Mon, 1 Oct 2007, jody wrote:
>>>> hosts ranks
>>>> node0 1,2,4
>>>> node1 3,4,6
>>> I guess there must be a typo:
>>> You can't assign one rank (4) to two nodes....
>>> And ranks start from 0 not from 1.
>>> Check this site,
>>> there might be some inforegarding your problem.
>>> users mailing list
>> users mailing list
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