Re: [Condor-users] GPU machines is "mixed" environment (conditional preemption)

[Lans Carstensen <Lans.Carstensen@xxxxxxxxxxxxxx>]

Greg Thain wrote:
>  On 10/07/2010 09:19 AM, Carsten Aulbert wrote:
> > However, now the big question how to address preemption. Essentially, 
> > I want
> > to ensure that the machine works as a standard compute nodes with 
> > multiple
> > cores (identically setup as others; sans vanilla universe jobs) in the 
> > absence
> > of any idle jobs which have "NeedGpu" set.
> I'm not sure I entirely understand your requirements, but I think you 
> can simply
> use the Machine RANK to prefer jobs with NeedGpu set.

I'm also a little confused as PREEMPTION_REQUIREMENTS is a 
condor_negotiator thing but you're talking about slot-level detail.  For 
that you need to use PREEMPT, which is the startd side.  You've got the 
basic formula from here:

https://condor-wiki.cs.wisc.edu/index.cgi/wiki?p=HowToReserveSlotForSpecialJobs

...but I think you're wanting to use STARTD_JOB_EXPRS so that you can 
refer to the attribute of the running job within the slot (MY.NeedsGpu) 
as well as the candidate job attribute (TARGET.NeedsGpu):

STARTD_JOB_EXPRS = NeedsGpu
PREEMPT = MY.NeedGpu =?= UNDEFINED && TARGET.NeedGpu =!= UNDEFINED

-- Lans Carstensen