[Bug 240051] top Reports Incorrect Swap File Size

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https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=240051

--- Comment #2 from John <jlmales at gmail.com> ---
(In reply to ota from comment #1)
As noted in initial bug report htop and swapinfo both report the correct swap
file size.  top does not report the correct swap file size at something less
than what is allocated for swap file size. That is the issue.

Further the amount of RAM installed does not determine what the reported size
of the swap file or sum of multiple swap files is.  Both swapinfo and htop
report the correct swap file size.  top does not report the correct swap file
size.  Therefore the issue is top failing to correctly report the swap file
size that has no bearing on the amount of ram installed.

Swap file was sized during FreeBSD install to accommodate short term and long
term RAM upgrades.

In theory there is no restriction on RAM size as function to determine swap
file size that can be allocated for any OS.  This includes IBM Mainframes that
have used Virtual Memory since the 1970s and therefore have used swap files as
a result since the 1970s.

In practice there may be limits simply due to extent of swap file/RAM page
thrashing/faults per second an OS can incur that is system/application specific
mix/active/activity and/or disk space wasted that will not be used for swap or
not used for swap much of the time.  System planning and testing enable the
swap file size and usage characterizations to be calculated.  The amount of
swap space defined during an install does not always mean the OS calculated
swap file size is taken as at time of install. The OS install calculated
default swap file size cannot take into account future system upgrades, nor
characterization usage patterns of system/applications of the swap file.

The amount of RAM currently install on the system is provided in the
information when the initial bug report was made.

I have worked with Virtual Memory based OSs since the 1970s.  I have lots of
experience with Virtual Memory and swap file space
allocations/characterizations on IBM Mainframes as well as Unix since the early
1990s (SunOS, AIX, System V, Linux, et al) based systems and some Unix
experience as early as the mid 1970s.

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