8274925: Shenandoah: shenandoah/TestAllocHumongousFragment.java test failed on lock rank check

[zhengyu123]

JDK-8273917 lowered MultiArray_lock rank from nonleaf+2 to nonleaf, that results several Shenandoah tests failed on lock rank check.

This patch lowers ShenandoahAllocFailureGC_lock rank by 2 to maintain original order.

Test:

• hotspot_gc_shenandoah

---

Progress

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Issue

• JDK-8274925: Shenandoah: shenandoah/TestAllocHumongousFragment.java test failed on lock rank check

Reviewers

• Aleksey Shipilev (@shipilev - Reviewer)

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.java.net/jdk pull/5865/head:pull/5865
$ git checkout pull/5865

Update a local copy of the PR:
$ git checkout pull/5865
$ git pull https://git.openjdk.java.net/jdk pull/5865/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 5865

View PR using the GUI difftool:
$ git pr show -t 5865

Using diff file

Download this PR as a diff file:
https://git.openjdk.java.net/jdk/pull/5865.diff

[bridgekeeper]

👋 Welcome back zgu! A progress list of the required criteria for merging this PR into master will be added to the body of your pull request. There are additional pull request commands available for use with this pull request.

[openjdk]

@zhengyu123 The following labels will be automatically applied to this pull request:

• hotspot-gc
• shenandoah

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[mlbridge]

Webrevs

• 01: Full - Incremental (c224b441)
• 00: Full (bad7be7c)

[shipilev]

Hold on a sec, I have questions...

I see MultiArray_lock is safepoint. Shouldn't this be safepoint - 1 then?
I think this would basically say "you can acquire any safepoint lock", right?
Also, does the same thing apply to _gc_waiters_lock?

Changing both locks to safepoint - 1 passes hotspot_gc_shenandoah for me here.

[zhengyu123]

Hold on a sec, I have questions...

I see MultiArray_lock is safepoint. Shouldn't this be safepoint - 1 then?
You see any difference with safepoint-1 and safepoint-2?

I do agree probably should be safepoint-1 because #5869 did that.

I think this would basically say "you can acquire any safepoint lock", right? Also, does the same thing apply to _gc_waiters_lock?

I thought about that. It appears that _gc_waiters_lock is only acquired vs. SH::collect(), where I don't see it is possible holding MultiArray_lock.

Changing both locks to safepoint - 1 passes hotspot_gc_shenandoah for me here.

I will make change on _alloc_failure_waiters_lock rank, but not sure we really need to change _gc_waiters_lock, what your opinion?

[shipilev]

I do agree probably should be safepoint-1 because #5869 did that.

Yes, I think Shenandoah never takes JNICritical_lock, so it is fine to have safepoint - 1 here.

I thought about that. It appears that _gc_waiters_lock is only acquired vs. SH::collect(), where I don't see it is possible holding MultiArray_lock.

I think it is technically possible to call SH::collect() from the Java code that holds the MultiArray_lock, as part of OOM allocation? I think it would be future-proof to accept all safepoint-rank locks in ShenandoahControlThread, i.e. make all of them safepoint - 1. You probably want to run tier1, tier2 with TEST_VM_OPTS=-XX:+UseShenandoahGC to confirm.

[shipilev]

Looks good, provided the tests pass.

[openjdk]

@zhengyu123 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:

8274925: Shenandoah: shenandoah/TestAllocHumongousFragment.java test failed on lock rank check

Reviewed-by: 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 24 new commits pushed to the master branch:

• 0d80f6c: 8274379: Allow process of unsafe access errors in check_special_condition_for_native_trans
• b870468: 8274347: Passing a nested switch expression as a parameter causes an NPE during compile
• 110e38d: 8274753: ZGC: SEGV in MetaspaceShared::link_shared_classes
• b7af890: 8274430: Remove some debug error printing code added in JDK-8017163
• aaf2401: 8274927: Remove unnecessary G1ArchiveAllocator code
• c55dd36: 8275008: gtest build failure due to stringop-overflow warning with gcc11
• 3edee1e: 8272723: Don't use Access API to access primitive fields
• 49f8ce6: 8274773: [TESTBUG] UnsafeIntrinsicsTest intermittently fails on weak memory model platform
• c032186: 8272968: AArch64: Remove redundant matching rules for commutative ops
• a05873a: 8274952: jdk/jfr/api/consumer/TestRecordedFrameType.java failed when c1 disabled
• ... and 14 more: https://git.openjdk.java.net/jdk/compare/6364719cd1c57220769ea580d958da8dc2fdf7f9...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.

[zhengyu123]

/integrate

[openjdk]

Going to push as commit 75f5145.
Since your change was applied there have been 27 commits pushed to the master branch:

• 83c3771: 8273881: Metaspace: test repeated deallocations
• 3f01d03: 8275021: Test serviceability/sa/TestJmapCore.java fails with: java.io.IOException: Stack frame 0x4 not found
• 3f07337: 8273614: Shenandoah: intermittent timeout with ConcurrentGCBreakpoint tests
• 0d80f6c: 8274379: Allow process of unsafe access errors in check_special_condition_for_native_trans
• b870468: 8274347: Passing a nested switch expression as a parameter causes an NPE during compile
• 110e38d: 8274753: ZGC: SEGV in MetaspaceShared::link_shared_classes
• b7af890: 8274430: Remove some debug error printing code added in JDK-8017163
• aaf2401: 8274927: Remove unnecessary G1ArchiveAllocator code
• c55dd36: 8275008: gtest build failure due to stringop-overflow warning with gcc11
• 3edee1e: 8272723: Don't use Access API to access primitive fields
• ... and 17 more: https://git.openjdk.java.net/jdk/compare/6364719cd1c57220769ea580d958da8dc2fdf7f9...master

Your commit was automatically rebased without conflicts.

[openjdk]

@zhengyu123 Pushed as commit 75f5145.

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