OAR Setup¶
CPUSET¶
The cpusets are a linux mechanism allowing to assign resources (CPU cores, memory) to processes. Cpusets are used in OAR to isolate jobs. At the time of writing, this separation is only performed for CPU cores in our GPU cluster. It is not configured for memory, although this can be useful to prevent a single user from using the RAM of the whole node.
After installing a GPU node as detailed in the machine installation tutorial, it is necessary to check if the cpuset property is configured correctly.
The number of virtual cores should be evenly distributed among the resources of a node.
For example with gpuhost22, there are 16 virtual cores (cat /proc/cpuinfo | grep processor) and 2 ressources (41 and 42) corresponding to the two GPU cards installed.
Consequently, each resource should use 8 cores.
This configuration should be performed on edgar by running these 2 commands as root:
oarnodesetting -r 41 --property "cpuset=0,1,2,3,4,5,6,7"
oarnodesetting -r 42 --property "cpuset=8,9,10,11,12,13,14,15"
You can check that cpusets are set properly with oarnodes | grep gpuhostXX and look at the cpuset property.