JDK-8275608: runtime/Metaspace/elastic/TestMetaspaceAllocationMT2 too slow

[tstuefe]

Small tweaks to make these elastic metaspace stress tests faster.

Before, runtime for individual tests was wobbling between 40+ seconds and some rare timeouts at 3+ minutes, depending on machine load and random luck. Now, we get a steadfast 35-37 seconds.

I tested this manually, checking the numbers that we really test what we want to test (a lot of arena activity). Also GHAs and SAP nightlies.

Thanks, Thomas

---

Progress

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Issue

• JDK-8275608: runtime/Metaspace/elastic/TestMetaspaceAllocationMT2 too slow

Reviewers

• Matthias Baesken (@MBaesken - Reviewer) ⚠️ Review applies to cea64e9
• Aleksey Shipilev (@shipilev - Reviewer) ⚠️ Review applies to 8b5ebfd

Reviewing

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[openjdk]

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[mlbridge]

Webrevs

• 04: Full - Incremental (20841723)
• 03: Full - Incremental (c934a0c3)
• 02: Full - Incremental (7101f3df)
• 01: Full - Incremental (8b5ebfd8)
• 00: Full (cea64e93)

[MBaesken]

Looks good to me; you might want to update the copyright headers too (no new review needed for that of course).

[openjdk]

@tstuefe 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:

8275608: runtime/Metaspace/elastic/TestMetaspaceAllocationMT2 too slow

Reviewed-by: mbaesken, shade

You can use pull request commands such as /summary, /contributor and /issue to adjust it as needed.

At the time when this comment was updated there had been 3 new commits pushed to the master branch:

• 15fd8a3: 8276102: JDK-8245095 integration reverted JDK-8247980
• e89b2c0: 8276086: Increase size of metaspace mappings
• 24cf480: 8276047: G1: refactor G1CardSetArrayLocker

Please see this link for an up-to-date comparison between the source branch of this pull request and the master branch.
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.

➡️ To integrate this PR with the above commit message to the master branch, type /integrate in a new comment.

[tstuefe]

Looks good to me; you might want to update the copyright headers too (no new review needed for that of course).

Thank you Matthias! Will update the copyright before pushing.

[shipilev]

Looks fine to me, some minor nits I wondered about below.

[shipilev]

Why these changes?

[shipilev]

Nevermind, got my reply.

[tstuefe]

As I wrote, I changed the test names, because I want to be able to call them individually with '#bla' and that does not work if the subtest name contains non-alphanumerics. I can do it in a separate RFE if you prefer.

[shipilev]

Yes, I don't mind doing it here.

[tstuefe]

I removed the renaming from this patch, its maybe cleaner to do it separately. Or, idk, maybe fix jtreg itself.

[shipilev]

Fixing jteg would be nice. There are plenty of tests with these dashed IDs, IIRC.

[tstuefe]

openjdk/jtreg#30

[tstuefe]

Not a committer to code-tools though. I'll need a sponsor.

[tstuefe]

Changes:

• Used volatile as Alexey suggested
• changed the breathe-in-and-out logic a bit. No need to count ticks on breathe in, the logic is:
  • allocate till we hit ceiling
  • deallocate a bit
  • again allocate until full
  • repeat 1000 times
    This leads to a reasonable small - but not 0 - number of re-created arenas, which was the intention of this test. Beforehand, allocation threads were too often recreated, we spent too much time in thread creation and -cleanup.

I also changed the test names, because I want to be able to call them individually with '#bla' and that does not work if the subtest name contains non-alphanumerics.

[tstuefe]

Thanks @shipilev and @MBaesken.
/integrate

[openjdk]

Going to push as commit d6d82f5.
Since your change was applied there have been 7 commits pushed to the master branch:

• a1ec4f9: 6854300: [TEST_BUG] java/awt/event/MouseEvent/SpuriousExitEnter/SpuriousExitEnter_3.java fails in jdk6u14 & jdk7
• 8cc5950: 8251468: X509Certificate.get{Subject,Issuer}AlternativeNames and getExtendedKeyUsage do not throw CertificateParsingException if extension is unparseable
• 4c3491b: 8017175: [TESTBUG] javax/swing/JPopupMenu/4634626/bug4634626.java sometimes failed on mac
• c0cda1d: 8273026: Slow LoginContext.login() on multi threading application
• 15fd8a3: 8276102: JDK-8245095 integration reverted JDK-8247980
• e89b2c0: 8276086: Increase size of metaspace mappings
• 24cf480: 8276047: G1: refactor G1CardSetArrayLocker

Your commit was automatically rebased without conflicts.

[openjdk]

@tstuefe Pushed as commit d6d82f5.

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