JDK-8312625: Test serviceability/dcmd/vm/TrimLibcHeapTest.java failed: RSS use increased

[tstuefe]

Trivial patch.

The test just fires jcmd System.trim_native_heap, but without preparing any special memory allocation conditions. Typically, we end up firing the command when VM initialization is done, and therefore end up trimming a lot of memory. But once in a blue moon concurrent allocations may be ongoing, so we may not trim anything, or even see increased RSS.

The patch just loosens the success condition to succeed if the trim happened, irregardless of how much memory had been trimmed.

---

Progress

• Change must be properly reviewed (1 review required, with at least 1 Reviewer)
• Change must not contain extraneous whitespace
• Commit message must refer to an issue

Issue

• JDK-8312625: Test serviceability/dcmd/vm/TrimLibcHeapTest.java failed: RSS use increased (Bug - P4)

Reviewers

• Kevin Walls (@kevinjwalls - Committer)
• David Holmes (@dholmes-ora - Reviewer)

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.org/jdk.git pull/15009/head:pull/15009
$ git checkout pull/15009

Update a local copy of the PR:
$ git checkout pull/15009
$ git pull https://git.openjdk.org/jdk.git pull/15009/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 15009

View PR using the GUI difftool:
$ git pr show -t 15009

Using diff file

Download this PR as a diff file:
https://git.openjdk.org/jdk/pull/15009.diff

Webrev

Link to Webrev Comment

[bridgekeeper]

👋 Welcome back stuefe! 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]

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

• serviceability

When this pull request is ready to be reviewed, an "RFR" email will be sent to the corresponding mailing list. If you would like to change these labels, use the /label pull request command.

[mlbridge]

Webrevs

• 00: Full (0c8e4ae3)

[kevinjwalls]

Looks good to me.

[tstuefe]

Thank you @kevinjwalls ! Unfortunately, you are not a Reviewer yet, so I guess I need a second one. @dholmes-ora ?

[dholmes-ora]

Okay I guess, though now all we are testing is that we fired of the right DCmd, not that the DCmd actually did something that worked.

Thanks.

[openjdk]

@tstuefe 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:

8312625: Test serviceability/dcmd/vm/TrimLibcHeapTest.java failed: RSS use increased

Reviewed-by: kevinw, dholmes

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 25 new commits pushed to the master branch:

• 2d05d35: 8312979: Fix assembler_aarch64.hpp after JDK-8311847
• 78a8a99: 8312488: tools/jpackage/share/AppLauncherEnvTest.java fails with dynamically linked libstdc++
• cb82c95: 8312415: Expand -Xlint:serial checks to enum constants with specialized class bodies
• c6396dc: 8039165: [Doc] MessageFormat null locale generates NullPointerException
• 36f3bae: 8312401: SymbolTable::do_add_if_needed hangs when called in InstanceKlass::add_initialization_error path with requesting length exceeds max_symbol_length
• e554fde: 8311592: ECKeySizeParameterSpec causes too many exceptions on third party providers
• 9606cbc: 8312524: [JVMCI] serviceability/dcmd/compiler/CompilerQueueTest.java fails
• 91fe032: 8312818: Incorrect format specifier in a HttpClient log message
• bd09880: 8312512: sspi.cpp avoid some NULL checks related to free and delete
• b35ccb2: 8312533: JFR: No message for JFR.view when data is missing
• ... and 15 more: https://git.openjdk.org/jdk/compare/f3ade388dac0b882e671462caa762138f44817fb...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.

[tstuefe]

Okay I guess, though now all we are testing is that we fired of the right DCmd, not that the DCmd actually did something that worked.

Thanks.

True, but unlike runtime/os/TestTrimNative.java, this old test did nothing to provoke a malloc spike we then could trim and measure anyway.

Thanks, David!

/integrate

[openjdk]

Going to push as commit 117f42d.
Since your change was applied there have been 25 commits pushed to the master branch:

• 2d05d35: 8312979: Fix assembler_aarch64.hpp after JDK-8311847
• 78a8a99: 8312488: tools/jpackage/share/AppLauncherEnvTest.java fails with dynamically linked libstdc++
• cb82c95: 8312415: Expand -Xlint:serial checks to enum constants with specialized class bodies
• c6396dc: 8039165: [Doc] MessageFormat null locale generates NullPointerException
• 36f3bae: 8312401: SymbolTable::do_add_if_needed hangs when called in InstanceKlass::add_initialization_error path with requesting length exceeds max_symbol_length
• e554fde: 8311592: ECKeySizeParameterSpec causes too many exceptions on third party providers
• 9606cbc: 8312524: [JVMCI] serviceability/dcmd/compiler/CompilerQueueTest.java fails
• 91fe032: 8312818: Incorrect format specifier in a HttpClient log message
• bd09880: 8312512: sspi.cpp avoid some NULL checks related to free and delete
• b35ccb2: 8312533: JFR: No message for JFR.view when data is missing
• ... and 15 more: https://git.openjdk.org/jdk/compare/f3ade388dac0b882e671462caa762138f44817fb...master

Your commit was automatically rebased without conflicts.

[openjdk]

@tstuefe Pushed as commit 117f42d.

💡 You may see a message that your pull request was closed with unmerged commits. This can be safely ignored.