sysctl-6.6-rc1

Long ago we set out to remove the kitchen sink on kernel/sysctl.c arrays and
placings sysctls to their own sybsystem or file to help avoid merge conflicts.
Matthew Wilcox pointed out though that if we're going to do that we might as
well also *save* space while at it and try to remove the extra last sysctl
entry added at the end of each array, a sentintel, instead of bloating the
kernel by adding a new sentinel with each array moved.

Doing that was not so trivial, and has required slowing down the moves of
kernel/sysctl.c arrays and measuring the impact on size by each new move.

The complex part of the effort to help reduce the size of each sysctl is being
done by the patient work of el señor Don Joel Granados. A lot of this is truly
painful code refactoring and testing and then trying to measure the savings of
each move and removing the sentinels. Although Joel already has code which does
most of this work, experience with sysctl moves in the past shows is we need to
be careful due to the slew of odd build failures that are possible due to the
amount of random Kconfig options sysctls use.

To that end Joel's work is split by first addressing the major housekeeping
needed to remove the sentinels, which is part of this merge request. The rest
of the work to actually remove the sentinels will be done later in future
kernel releases.

At first I was only going to send his first 7 patches of his patch series,
posted 1 month ago, but in retrospect due to the testing the changes have
received in linux-next and the minor changes they make this goes with the
entire set of patches Joel had planned: just sysctl house keeping. There are
networking changes but these are part of the house keeping too.

The preliminary math is showing this will all help reduce the overall build
time size of the kernel and run time memory consumed by the kernel by about
~64 bytes per array where we are able to remove each sentinel in the future.
That also means there is no more bloating the kernel with the extra ~64 bytes
per array moved as no new sentinels are created.

Most of this has been in linux-next for about a month, the last 7 patches took
a minor refresh 2 week ago based on feedback.
-----BEGIN PGP SIGNATURE-----
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=sq2p
-----END PGP SIGNATURE-----