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Please do not use the torque directive mppnppn in your job scrpts

August 2, 2013 (0 Comments)

As of 8/15 12:30 PDT, the submit filter was updated to allow the #PBS -l nodes directive to be used in the jobs submitted through batch scripts. We are still experimenting with this directive, please report any problem you see with this directive. 8/21/2013

 

Edison has some issues with the explicit use of #PBS -l mppnppn=48  to use Hyper-Threading (HT). Please do not use it. To run with Hyper-Threading, please request needed nodes as you would normally do for a non-HT job, ie., use mppwidth/24 to request the number of nodes you need, and then use the aprun option -j2 to use all the cores on the nodes. So the following job script is appropriate to use 2 nodes and use all 96 logical cores on the two nodes.

#PBS -l mppwidth=48

...

aprun -j 2 -n 96 ./a.out

Please note, the mppnppn is not used explicitly, which means then the default value of mppnppn=24 is used.

Or alternatively, you can use the nodes directive to request nodes.

qsub -I -l nodes=2 -q debug

...

aprun -j2 -n96 ./a.out

 

 


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