8373347: [lworld] Minor cleanups in the memory directory

[stefank]

There are a few left-over blank line changes, redundant includes, and unused code in the memory/ directory. I suggest that we clean those out to make it nicer to review the patch.

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Issue

• JDK-8373347: [lworld] Minor cleanups in the memory directory (Enhancement - P4)

Reviewers

• Paul Hübner (@Arraying - Author)
• Frederic Parain (@fparain - Committer)

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[openjdk]

@stefank This change now passes all automated pre-integration checks.

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8373347: [lworld] Minor cleanups in the memory directory

Reviewed-by: phubner, fparain

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[mlbridge]

Webrevs

• 00: Full (1fb37c3c)

[Arraying]

LGTM, although maybe someone knows the historic reason of why we had do_oop_no_buffering to begin with.

[fparain]

It is a remain of an experiment to use a small thread-local area to store buffered values, which are often short lived, with a kind of automatic reclamation based on frame exits (I'm simplifying here). The idea was to avoid filling the Java heap with those buffered values. It worked but performance was bad. Browsing interpreter frames to find which values in this thread-local area were still alive was expensive, and the ratio cost/amount_of_memory_freed was not good. At the end, the Java heap GC was more efficient to handle those short lived buffered values, especially with generational GCs.

[stefank]

Thanks for the reviews. This passed tier1 testing.
/integrate

[openjdk]

@stefank
Your change (at version 1fb37c3) is now ready to be sponsored by a Committer.

[fparain]

/sponsor

[openjdk]

Going to push as commit 6e15674.

[openjdk]

@fparain @stefank Pushed as commit 6e15674.

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