8297292: java/nio/channels/FileChannel/FileExtensionAndMap.java is too slow

[bplb]

Reduce the test’s disk space requirement by one third and the total number of files tested by half. With this change, the test was observed to still fail with a SIGBUS using JDK 11.0.15 on Linux 5.15.0-58. The test’s run time decreased by about two thirds: for one sample run from 29m56s to 10m13s in the CI on Linux-x64. A run with 50 repeats had no failures.

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Issue

• JDK-8297292: java/nio/channels/FileChannel/FileExtensionAndMap.java is too slow

Reviewers

• Jaikiran Pai (@jaikiran - Reviewer) ⚠️ Review applies to 31d5700b

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[mlbridge]

Webrevs

• 02: Full - Incremental (44bc728a)
• 01: Full - Incremental (0be05b22)
• 00: Full (31d5700b)

[jaikiran]

Hello Brian, the change looks fine to me. FileExtensionAndMap.java will need a copyright year update before integrating.

[openjdk]

@bplb 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:

8297292: java/nio/channels/FileChannel/FileExtensionAndMap.java is too slow

Reviewed-by: jpai

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 40 new commits pushed to the master branch:

• 4539899: 8301480: Replace NULL with nullptr in os/posix
• 1428db7: 8301224: Replace NULL with nullptr in share/gc/shared/
• c25b4f4: 8301578: Perform output outside synchronization in Module.class
• 5830c03: 8302004: InlineTree should consult replay file in release build
• c8ace48: 8301072: Replace NULL with nullptr in share/oops/
• 1c7b09b: 8302069: javax/management/remote/mandatory/notif/NotifReconnectDeadlockTest.java update
• 837d464: 8302125: Make G1 full gc abort the VM after failing VerifyDuringGC verification
• 723433d: 8302117: IgnoreUnrecognizedVMOptions flag causes failure in ArchiveHeapTestClass
• e245620: 8293198: [vectorapi] Improve the implementation of VectorMask.indexInRange()
• b814cfc: 8178806: Better exception logging in crypto code
• ... and 30 more: https://git.openjdk.org/jdk/compare/638d612c6b7c08c1f7be0d4e75e9f8a6dca1ef19...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.

[AlanBateman]

10mins is still very slow for a test in this area, I wonder if there is a better way to test this scenario that would run in a shorter time.

I checked the tier2 runs in our CI and it looks like the slowest FileChannel tests right now take no more than 1m30s, so maybe that is the ballpark should be aiming for on this one.

[bplb]

FileExtensionAndMap.java was added by the change which resolved JDK-8168628. That change was backed out of JDK 11 because it broke sparse files. The underlying issue was really Unsafe::copy[Swap]Memory not using memory guards which was tracked in JDK-8191278. The fix for this latter issue added the test test/hotspot/jtreg/runtime/Unsafe/InternalErrorTest.java which is presumably sufficient to test for the underlying cause for which FileExtensionAndMap.java is also testing. Given this quasi duplication, it appears safe to simply remove FileExtensionAndMap.java altogether.

[AlanBateman]

The deletion looks fine.

[bplb]

/integrate

[openjdk]

Going to push as commit 84e4799.
Since your change was applied there have been 44 commits pushed to the master branch:

• 57798dd: 6595142: (spec) ByteArrayInputStream treats bytes, not characters
• 880f52f: 8301638: A number of nsk/jdi invokemethod tests should be converted to create virtual threads
• db1b48e: 8302167: Avoid allocating register in fast_lock()
• 582b943: 8278965: crash in SymbolTable::do_lookup
• 4539899: 8301480: Replace NULL with nullptr in os/posix
• 1428db7: 8301224: Replace NULL with nullptr in share/gc/shared/
• c25b4f4: 8301578: Perform output outside synchronization in Module.class
• 5830c03: 8302004: InlineTree should consult replay file in release build
• c8ace48: 8301072: Replace NULL with nullptr in share/oops/
• 1c7b09b: 8302069: javax/management/remote/mandatory/notif/NotifReconnectDeadlockTest.java update
• ... and 34 more: https://git.openjdk.org/jdk/compare/638d612c6b7c08c1f7be0d4e75e9f8a6dca1ef19...master

Your commit was automatically rebased without conflicts.

[openjdk]

@bplb Pushed as commit 84e4799.

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