[cfarm-users] Fixing CPU/core/threads count

[Baptiste Jonglez]

Hi,

Following up on a thread from 2018 [1], we still have issue with counting
the number of CPU, cores and threads on "exotic" machines.

I gave a try at hwloc on all farm machines, below is the result where:

M = machine
N = node (NUMA node)
P = package
C = core
T = pu (thread)


gcc10   M1 N4 P2 C24 T24
gcc13   M1 N2 P2 C4 T4
gcc14   M1 N P2 C8 T8
gcc22   M1 N P C2 T2
gcc23   M1 N P C2 T2
gcc45   M1 N P C4 T4
gcc67   M1 N P1 C4 T8
gcc70   M1 N P1 C1 T2
gcc110  M1 N2 P16 C16 T64
gcc112  M1 N4 P4 C20 T160
gcc113  M1 N P C8 T8
gcc114  M1 N P C8 T8
gcc115  M1 N P C8 T8
gcc116  M1 N P C8 T8
gcc117  M1 N P4 C8 T8
gcc120  M1 N2 P2 C16 T32
gcc121  M1 N2 P2 C16 T32
gcc122  M1 N2 P2 C16 T32
gcc123  M1 N2 P2 C16 T32
gcc135  M1 N2 P2 C32 T128
gcc202  M1 N1 P1 C8 T64
gcc203  M1 N2 P4 C4 T32

Can someone with experience with each kind of machine make sense of this
data, and determine which field we should use for "CPU" (sockets), "cores"
and "thread" in https://cfarm.tetaneutral.net/machines/list/ ?

From a first look, cores and threads seem to be correctly detected.
To get the number of CPU sockets, "NUMA node" seems rather unreliable
compared to "package", but both sometimes give strange results
(e.g. gcc110).

Maybe we should just stop trying to determine the number of CPU sockets
except on x86 systems?  Does anybody need this kind of data?


The data above was obtained with "hwloc-calc -N $type all", the full command is:

    # echo M$(hwloc-calc -N machine all) N$(hwloc-calc -N numanode all 2>/dev/null) P$(hwloc-calc -N package all 2>/dev/null) C$(hwloc-calc -N core all) T$(hwloc-calc -N pu all)

Thanks,
Baptiste

[1] https://lists.tetaneutral.net/pipermail/cfarm-users/2018-November/000424.html
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