cpu_count(logical=False) returns big number on Linux

[giampaolo]

This occurs on Ubuntu 18.04 (it didn't on 16.04) with kernel 4.15.0-29:

======================================================================
FAIL: psutil.tests.test_system.TestSystemAPIs.test_cpu_count
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/giampaolo/svn/psutil/psutil/tests/test_system.py", line 275, in test_cpu_count
    self.assertGreaterEqual(logical, physical)
AssertionError: 8 not greater than or equal to 65534

For some reason /proc/cpuinfo reports 65534:

$ cat /proc/cpuinfo
...
processor   : 7
vendor_id   : GenuineIntel
cpu family  : 6
model       : 94
model name  : Intel(R) Core(TM) i7-6700HQ CPU @ 2.60GHz
stepping    : 3
microcode   : 0xc2
cpu MHz     : 1553.590
cache size  : 6144 KB
physical id : 0
siblings    : 8
core id     : 3
cpu cores   : 65534
...

[giampaolo]

lscpu utility correctly reports the number of cores ("Core(s) per socket"):

Architecture:        x86_64
CPU op-mode(s):      32-bit, 64-bit
Byte Order:          Little Endian
CPU(s):              8
On-line CPU(s) list: 0-7
Thread(s) per core:  2
Core(s) per socket:  4
...

lscpu source code:
https://github.com/karelzak/util-linux/blob/master/sys-utils/lscpu.c

[giampaolo]

I am no longer able to reproduce this. I suppose it was a kernel bug which got fixed after an update or something... Closing.