[NetBSD] virtual_memory() metrics are completely wrong

[giampaolo]

Summary

• OS: NetBSD 8.0
• Architecture: amd64
• Type: core

Description

$ python3 scripts/meminfo.py
MEMORY
------
Total      :  972.7M
Available  :  959.1M
Percent    :     1.4
Used       :    1.1G
Free       :  173.6M
Active     :  434.3M
Inactive   :  258.4M
Buffers    :  509.4M
Cached     :  692.9M
Shared     :    0.0B
Wired      :  280.0K

In here:

• available mem is almost the same as total (unrealistic)
• used is higher than total; there's also a failing test:

======================================================================
FAIL: psutil.tests.test_system.TestMemoryAPIs.test_virtual_memory
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/vagrant/psutil/psutil/tests/test_system.py", line 286, in test_virtual_memory
    raise self.fail("%r > total (total=%s, %s=%s)"
          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
AssertionError: 'used' > total (total=1019899904, used=1210896384)