Hi Chris,
this is not correct. From the slurm.conf manpage:
CPUs:
Number of logical processors on the node (e.g. "2"). CPUs and Boards
are mutually exclusive. It can be set to the total number of sockets,
cores or threads. This can be useful when you want to schedule only
the cores on a hyper-threaded node. If CPUs is omitted, it will be set
equal to the product of Sockets, CoresPerSocket, and ThreadsPerCore.
The default value is 1.
If one only wants to schedule by cores, even if hyperthreading is
enabled, you need to set CPUs to Sockets*CoresPerSocket. See also this
part from SelectTypeParameters:
CR_Core_Memory:
Cores and memory are consumable resources. On nodes with
hyper-threads, each thread is counted as a CPU to satisfy a job's
resource requirement, but multiple jobs are not allocated threads on the
samecore. The count of CPUs allocated to a job may be rounded up to
account for every CPU on an allocated core. Setting a value for
DefMemPerCPU is strongly recommended.
Especially the part "every CPU on an allocated core".
To me it looks like CPUs is the synonym for hardware threads.
Best
Marcus
On 05/05/2018 02:42 PM, Chris Samuel wrote:
On Saturday, 5 May 2018 2:45:19 AM AEST Eric F. Alemany wrote:
With Ray suggestion i have a error message for each nodes. Here i am giving
you only one error message from a node.
sacct: error: NodeNames=radonc01 CPUs=32 doesn't match
Sockets*CoresPerSocket*ThreadsPerCore (16), resetting CPUs
The interesting thing is if you follow the
Sockets*CoresPerSocket*ThreadsPerCore formula 2x8x2 = 32 however look above
and it says (16) - Strange, no ?
No, Slurm is right. CPUS != threads. You've got 16 CPU cores, each with 2
threads. So in this configuration you can schedule 16 tasks per node and each
task can use 2 threads.
What does "slurmd -C" say on that node?
All the best,
Chris
--
Marcus Wagner, Dipl.-Inf.
IT Center
Abteilung: Systeme und Betrieb
RWTH Aachen University
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