8366037: Remove oopDesc::mark_addr()

[kimbarrett]

Please review this change that removes the function oopDesc::mark_addr().
It's kind of a suspicious function, since it is casting away the volatile for
a location that has concurrent reads and writes. But there isn't any code that
examines the value at the obtained address. Instead, it's just used as the
base address for a few prefetches. We change those places accordingly, and
remove the now unused mark_addr function.

Testing: mach5 tier1

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Progress

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Issue

• JDK-8366037: Remove oopDesc::mark_addr() (Enhancement - P4)

Reviewers

• Aleksey Shipilev (@shipilev - Reviewer)
• Stefan Karlsson (@stefank - Reviewer)
• Thomas Schatzl (@tschatzl - Reviewer)

Reviewing

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[openjdk]

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

ℹ️ This project also has non-automated pre-integration requirements. Please see the file CONTRIBUTING.md for details.

After integration, the commit message for the final commit will be:

8366037: Remove oopDesc::mark_addr()

Reviewed-by: shade, stefank, tschatzl

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At the time when this comment was updated there had been 25 new commits pushed to the master branch:

• 68abf76: 8366105: Update link to the external RuleBasedBreakIterator documentation
• 5013d69: 8365633: Incorrect info is reported on hybrid CPU
• e38c6f9: 8365656: [ubsan] G1CSetCandidateGroup::liveness() reports division by 0
• ... and 22 more: https://git.openjdk.org/jdk/compare/09aad0aea8b9f9fda14c5b18ae67b30ffce817d9...master

As there are no conflicts, your changes will automatically be rebased on top of these commits when integrating. If you prefer to avoid this automatic rebasing, please check the documentation for the /integrate command for further details.

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[mlbridge]

Webrevs

• 01: Full - Incremental (15b34fcf)
• 00: Full (fc5f763b)

[shipilev]

This looks fine.

[stefank]

Looks good.

I wonder though if it would make sense to have a function, say, void* oopDesc::base_addr() and use that instead of the added casts?

[kimbarrett]

I wonder though if it would make sense to have a function, say, void* oopDesc::base_addr() and use that instead of the added casts?

I like that better, so changed accordingly. Will need re-review from everyone.
@shipilev @stefank @tschatzl

[shipilev]

This looks fine. TIL that you can overload methods with cv-qualifiers.

[kimbarrett]

Thanks for reviews @shipilev @stefank @tschatzl

[kimbarrett]

/integrate

[openjdk]

Going to push as commit c203e70.
Since your change was applied there have been 34 commits pushed to the master branch:

• 2b44ed7: 8365807: (fs) Two-arg UnixFileAttributes.getIfExists should not use exception for control flow
• 6a480ad: 8366126: Feedback on two errors in JSR 400
• caaef3a: 8350920: Allow inherited member summaries to be viewed inline
• ... and 31 more: https://git.openjdk.org/jdk/compare/09aad0aea8b9f9fda14c5b18ae67b30ffce817d9...master

Your commit was automatically rebased without conflicts.

[openjdk]

@kimbarrett Pushed as commit c203e70.

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