[gridengine users] making core binding useful for MPI

Dave Love d.love at liverpool.ac.uk
Tue Jun 7 13:28:18 UTC 2011


Reuti <reuti at staff.uni-marburg.de> writes:

> Hi,
>
> Am 25.05.2011 um 17:30 schrieb Dave Love:
>
>> It seems that core binding currently isn't typically useful with MPI
>> jobs.  The pe method needs exclusive node access and a fixed  
>> allocation
>> rule that you need to know in advance, but then you could have the mpi
>> do it anyhow (e.g. openmpi paffinity_alone) which works more  
>> generally.
>> (See past discussion.)  There seem similar restrictions on the set
>> method in practice -- at least needing a fixed allocation rule, as you
>> have to specify a fixed core count.
>>
>> It looks straightforward to implement binding a number of cores  
>> equal to
>> the host-local slot count.  Does ayone see a problem with that or have
>> strong feelings how to specify it?  I'd be inclined to let bare
>> `-binding set' do it, but otherwise maybe a new type like `setslots'  
>> analogous
>> to `set'.
>
> what would be the difference to the current implementation?
>
> -- Reuti

Binding a number of cores equal to the allocated slot count for the node
rather than a fixed number.  E.g. you have 16-core nodes with $fill_up
and 24-slot (process) job, you'd probably want to bind 16 on one and 8
on another and you can't currently specify that.

-- 
Excuse the typping -- I have a broken wrist



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