8347126: gc/stress/TestStressG1Uncommit.java gets OOM-killed

[shipilev]

One of my testing nodes caught the OOM kill for the VM carrying the test. The default configuration turns the VM that test runs as the driver into a memory hog. On 48-core / 64G machine, the test configured itself to take 13 workers each allocating 1G. This ballooned the heap size to 13G -- e.g. about 25% of host memory -- which is well beyond the usual footprint for a single test VM (~2GB). Naturally, this runs into a high chance of being OOM killed under high test parallelism.

I think the solution is to cut down the heap size we run with, and balance the number of workers a bit more finely. I looked around at sibling tests and 1G seems to be a common heap size for these tests.

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Issue

• JDK-8347126: gc/stress/TestStressG1Uncommit.java gets OOM-killed (Bug - P4)

Reviewers

• Thomas Schatzl (@tschatzl - Reviewer)
• Guoxiong Li (@lgxbslgx - Reviewer)

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[shipilev]

On my M1, the test now configures to much more reasonable occupancy.

# Before
0s: Using 7 workers, each allocating: ~936M (=6552M total)

# After
0s: Using 9 workers, each allocating: ~91M (=819M total)

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8347126: gc/stress/TestStressG1Uncommit.java gets OOM-killed

Reviewed-by: tschatzl, gli

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At the time when this comment was updated there had been 42 new commits pushed to the master branch:

• 4d18e5a: 8346872: tools/jpackage/windows/WinLongPathTest.java fails
• 92ad8a1: 8346052: JFR: Incorrect average value in 'jfr view'
• 672c413: 8345337: JFR: jfr view should display all direct subfields for an event type
• afe5434: 8347163: Javadoc error in ConstantPoolBuilder after JDK-8342468
• f696d9c: 8346239: Improve memory efficiency of JimageDiffGenerator
• cbabc04: 8332506: SIGFPE In ObjectSynchronizer::is_async_deflation_needed()
• 9872421: 8347094: Inline CollectedHeap::increment_total_full_collections
• b741f3f: 8343629: More MergeStore benchmark
• b0c935c: 8347047: Cleanup action passed to MemorySegment::reinterpret keeps old segment alive
• bcefab5: 8342468: Improve API documentation for java.lang.classfile.constantpool
• ... and 32 more: https://git.openjdk.org/jdk/compare/f1d85ab3e61f923b4e120cf30e16109e04505b53...master

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