Merge branch 'map-charge-cleanup'

Roman Gushchin says:

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During my work on memcg-based memory accounting for bpf maps
I've done some cleanups and refactorings of the existing
memlock rlimit-based code. It makes it more robust, unifies
size to pages conversion, size checks and corresponding error
codes. Also it adds coverage for cgroup local storage and
socket local storage maps.

It looks like some preliminary work on the mm side might be
required to start working on the memcg-based accounting,
so I'm sending these patches as a separate patchset.
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Signed-off-by: Alexei Starovoitov <ast@kernel.org>