8273895: compiler/ciReplay/TestVMNoCompLevel.java fails due to wrong data size with TieredStopAtLevel=2,3

[chhagedorn]

TestVMNoCompLevel.java is first letting the VM crash with -XX:CICrashAt=1 (method TestMain::test()), then removes the compilation level information from the compile entry in the replay file and then replay compiles with and without tiered compilation. When running the replay file with tiered compilation off, it results in the assertion failure.

When letting the VM crash with -XX:TieredStopAtLevel=2,3 (C1 only), we get a slightly different MDO size for TestMain::test() compared to letting the VM crash with -XX:-TieredCompilation (C2 only). The C1 reported MDO for TestMain::test() is slightly smaller than the C2 MDO. The reason for that can be traced back to JDK-8251462 which changed this code in is_speculative_trap_bytecode(). This now only returns true if C2 is enabled. is_speculative_trap_bytecode() is called when initializing an MDO here:

jdk/src/hotspot/share/oops/methodData.cpp

Line 1235 in 2ef6871

needs_speculative_traps = needs_speculative_traps || is_speculative_trap_bytecode(c);

If C2 is enabled, then we reserve some extra data space for trap data. But when running with C1 only, this is no longer done since JDK-8251462, so we allocate no extra data space in the MDO for the crashing method TestMain::test().

When now crashing first with -XX:TieredStopAtLevel=2,3, we collect an MDO without the extra trap data for the replay file. But when replay compiling afterwards with -XX:-TieredCompilation, we try to compile it with C2 (we removed the compilation level from the compile entry). We initialize the MDO of TestMain::test() with the extra trap data which is a mismatch to the reported C1 only MDO without extra trap data and we fail with the assertion.

I suggest to just not run this test with -XX:TieredStopAtLevel=2,3 to not try to compile a C1 method with profiling data with C2 in order to avoid this MDO mismatch assertion failure. I'm not sure either of the value of this test as this old format is not created anymore. But we might still want to keep this test around.

Thanks,
Christian

---

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Issue

• JDK-8273895: compiler/ciReplay/TestVMNoCompLevel.java fails due to wrong data size with TieredStopAtLevel=2,3

Reviewers

• Vladimir Kozlov (@vnkozlov - Reviewer)
• Dean Long (@dean-long - Reviewer)

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[mlbridge]

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• 00: Full (63ef7889)

[vnkozlov]

Good.

[openjdk]

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

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

8273895: compiler/ciReplay/TestVMNoCompLevel.java fails due to wrong data size with TieredStopAtLevel=2,3

Reviewed-by: kvn, dlong

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 18 new commits pushed to the master branch:

• 8c022e2: 8270434: JDI+UT: Unexpected event in JDI tests
• b982904: 8271073: Improve testing with VM option VerifyArchivedFields
• bc48a0a: 8273902: Memory leak in OopStorage due to bug in OopHandle::release()
• 9c5441c: 8271569: Clean up the use of CDS constants and field offsets
• 12fa707: 8261941: Use ClassLoader for unregistered classes during -Xshare:dump
• 7e92abe: 8273710: Remove redundant stream() call before forEach in jdk.jdeps
• 59b2478: 8273659: Replay compilation crashes with SIGSEGV since 8271911
• 5e4d09c: 8273300: Check Mutex ranking during a safepoint
• c86e24d: 8271954: C2: assert(false) failed: Bad graph detected in build_loop_late
• 14dc517: 8273372: Remove scavenge trace message in psPromotionManager
• ... and 8 more: https://git.openjdk.java.net/jdk/compare/74ffe12267cb3ae63072a06f50083fd0352d8049...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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[chhagedorn]

Thanks Vladimir and Dean for your reviews!

[chhagedorn]

/integrate

[openjdk]

Going to push as commit a561eac.
Since your change was applied there have been 31 commits pushed to the master branch:

• d2388b7: 8273959: Some metaspace diagnostic switches should be develop
• dc7f452: 8273815: move have_special_privileges to os_posix for POSIX platforms
• 7c9868c: 8273454: C2: Transform (-a)(-b) into ab
• bb9d142: 8273958: gtest/MetaspaceGtests executes unnecessary tests in debug builds
• 2a2e919: 8273685: Remove jtreg tag manual=yesno for java/awt/Graphics/LCDTextAndGraphicsState.java & show test instruction
• 8302061: 8273774: CDSPluginTest should only expect classes_nocoops.jsa exists on supported 64-bit platforms
• 2f8c221: 8273681: Add Vector API vs Arrays.mismatch intrinsic benchmark
• 17f7a45: 8273913: Problem list some headful client jtreg tests that fail on macOS 12
• 27d747a: 8273877: os::unsetenv unused
• 35f6f1d: 8273808: Cleanup AddFontsToX11FontPath
• ... and 21 more: https://git.openjdk.java.net/jdk/compare/74ffe12267cb3ae63072a06f50083fd0352d8049...master

Your commit was automatically rebased without conflicts.

[openjdk]

@chhagedorn Pushed as commit a561eac.

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