Re: [HTCondor-users] sharing CPU

[Todd Tannenbaum <tannenba@xxxxxxxxxxx>]

On 3/2/2015 11:37 AM, Ricardo Oda wrote:
> That's really nice, Thanks Todd.
> Some questions:
>
>
>     Although it is a bit inelegant, you can achieve what you want right
>     now by telling HTCondor your machine has more CPU cores than it
>     really does via the NUM_CPUS config settings, which defaults to
>     $(DETECTED_CPUS). So for instance, you could tell HTCondor a machine
>     has 4 times the cores it really does via the following in
>     condor_config :
>
>         NUM_CPUS = 4 * $(DETECTED_CPUS)
>
>
> When I do what is told above, will Condor correctly assign each core for
> exactly 4 slots?
> Are cores hard mapped to slots?

By default, HTCondor will create one static slot for each CPU core it 
thinks exist on the system, and divide RAM amongst the number of slots. 
 But you can put knobs in the condor_config file to override this and 
create an arbitrary number of slots where each slot can contain an 
arbitrary number of resources like cpu cores, memory, disk, gpu devices, 
etc.  There is a section of the HTCondor Manual that talks about 
"Dividing System Resources in Multi-core Machines" that covers these 
settings; see http://goo.gl/FbhFQE

Feel free to ask here for help if you have trouble, many folks on this 
list have sliced and diced big servers in all sorts of creative ways and 
can write these configuration settings in their dreams :).

> And you think this trick of increasing the number of detected cores will
> also work with dynamic slots?

Yes.

regards,
Todd