8268390: G1 concurrent gc upgrade to full gc not working

[kstefanj]

Please review this small change to enable concurrent GCs to be upgraded to Full collections when there are no free regions.

Summary
During the review of PR #4342 it was noted that we currently never upgrade concurrent GCs (from VM_G1TryInitiateConcMark::doit()) to full collections. In should_upgrade_to_full_gc() there was a check to always return false for "concurrent" GC-causes. There is no obviously good reason for this, and this change will enable concurrent GCs to be upgraded.

This could not be included in PR #4342 because that would make us hit the same problem as reported in JDK-8195158. The fix back then was to not upgrade concurrent GCs. The approach used now, which was added by PR #4357, is to use another GC cause for upgraded GCs.

What this change does is basically just removing the should_do_concurrent_full_gc() check from should_upgrade_to_full_gc() and once that is done has_regions_left_for_allocation() might as well be folded into should_upgrade_to_full_gc()

Testing
Manual testing to verify this does not cause the assertion failure from JDK-8195158. Currently running Mach5 testing.

---

Progress

• Change must not contain extraneous whitespace
• Commit message must refer to an issue
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Issue

• JDK-8268390: G1 concurrent gc upgrade to full gc not working

Reviewers

• Kim Barrett (@kimbarrett - Reviewer)
• Thomas Schatzl (@tschatzl - Reviewer)

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.java.net/jdk pull/4435/head:pull/4435
$ git checkout pull/4435

Update a local copy of the PR:
$ git checkout pull/4435
$ git pull https://git.openjdk.java.net/jdk pull/4435/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 4435

View PR using the GUI difftool:
$ git pr show -t 4435

Using diff file

Download this PR as a diff file:
https://git.openjdk.java.net/jdk/pull/4435.diff

[bridgekeeper]

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[openjdk]

@kstefanj The following label will be automatically applied to this pull request:

• hotspot-gc

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[mlbridge]

Webrevs

• 00: Full (0acddf1a)

[kimbarrett]

Looks good.

[openjdk]

@kstefanj 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:

8268390: G1 concurrent gc upgrade to full gc not working

Reviewed-by: kbarrett, tschatzl

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 17 new commits pushed to the master branch:

• d4377af: 8263303: C2 compilation fails with assert(found_sfpt) failed: no node in loop that's not input to safepoint
• dd1cbad: 8268285: vmTestbase/nsk/jvmti/GetThreadState/thrstat002 failed with "Wrong thread "thr1" (...) state after SuspendThread"
• ece3ae3: 8268388: Update large pages information in Java manpage
• 2623b0b: 8268475: execute runtime/InvocationTests w/ -UseVtableBasedCHA
• f839308: 8268407: ProblemList sun/tools/jstat/jstatLineCountsX.sh on linux-aarch64 due to JDK-8268211
• 58ba48b: 8268192: LambdaMetafactory with invokespecial causes VerificationError
• b41f3f8: 8268478: JVMCI tests failing after JDK-8268052
• 7ff6e7b: 8267954: Shared classes that failed to load should not be loaded again
• 991ca14: 8267430: GraphicsDevice.setDisplayMode(REFRESH_RATE_UNKNOWN) throws IAE: Unable to set display mode!
• bf29a01: 8228343: JCMD and attach fail to work across Linux Container boundary
• ... and 7 more: https://git.openjdk.java.net/jdk/compare/caf7f49887db3ea26ee302f37941f196b3a76f3f...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.

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

[kstefanj]

Testing looks good, tier1 - tier3 + additional GC tests.

[tschatzl]

Lgtm.

[kstefanj]

Thanks @tschatzl and @kimbarrett.

/integrate

[openjdk]

@kstefanj Since your change was applied there have been 28 commits pushed to the master branch:

• e0c0b13: 8268534: some serviceability/jvmti tests should be run in driver mode
• 92f0b6d: 8268532: several serviceability/attach tests should be run in driver mode
• 964118f: 8268538: mark hotspot serviceability/logging tests which ignore external VM flags
• 05090fc: 8268536: mark hotspot serviceability/dcmd tests which ignore external VM flags
• ae29f9c: 8268530: resourcehogs/serviceability/jvmti/GetObjectSizeOverflow.java should be run in driver mode
• ea19b04: 8268481: Delete JAWT test files for mac
• f271eb8: 8268303: Incorrect casts in JfrWriterHost::write for Ticks and Tickspan
• ab01cb5: 8268339: Upstream: 8267989: Exceptions thrown during upcalls should be handled
• 1fd8146: 8268461: ARM32: vector intrinsics reaches ShouldNotReachHere
• 78b09ab: 8268463: Windows 32bit build fails in DynamicCodeGenerated\libDynamicCodeGenerated.cpp
• ... and 18 more: https://git.openjdk.java.net/jdk/compare/caf7f49887db3ea26ee302f37941f196b3a76f3f...master

Your commit was automatically rebased without conflicts.

Pushed as commit f770f77.

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