[Mauiusers] Questions regarding "tasks" and the cfg file.
garrick at usc.edu
Wed Sep 17 13:15:01 MDT 2008
On Wed, Sep 17, 2008 at 11:12:41AM -0500, Michael Homa alleged:
> In order to test, I wrote a simple hello_world program in C. When I submit
> the program for execution, I see that the number of tasks is 6:
> Job ID Username Queue Jobname SessID NDS TSK Memory Time S Time
> 317 mhoma dedicate hello_worl -- 1 6 --- 00:30 Q --
What did the job actually request? nodes=1:ppn=6? ncpus=6? Neither of those
requests can be answered with quad-proc machines.
> and the job remains queued because:
> "job cannot run in partition DEFAULT (idle procs do not meet requirements
> : 0 of 6 procs found)"
The job is requesting resources that can't be met by your nodes.
> The dedicated queue has three dual CPU, dual cores and was established in
> argo17-1 np=4 Linux2.i86pc dualcore amd smp dedicated
> argo18-2 np=4 Linux2.i86pc dualcore amd smp dedicated
> argo18-3 np=4 Linux2.i86pc dualcore amd smp dedicated
I don't see nodes here that can satisfy the request of nodes=1:ppn=6.
> According to the admin manual, "by default, a task maps directly to a
> single processor within a job."
> A few questions:
> 1) What configuration variable controls this setting? In other words,
> how does one change maui so that a single processor can handle
> multiple tasks from the same job. By its very nature, a hello_world
> stub should not require six processors. Of course, my job will
> queue; it's asking for six processors and there are only four
> available. But, I'm surprised that the message says "0 of 6 found".
Don't change the number of CPUs in a task. Down that road lies madness.
> 2) I'm unclear as to how the "task" number is derived? I noticed that
> my hello_world has a PE of 6. Is that a coincidence or does the
> resulting PE become the number of tasks? Why six processors for
We would need to see that actual request.
Garrick Staples, GNU/Linux HPCC SysAdmin
University of Southern California
Please avoid sending me Word or PowerPoint attachments.
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