8270801: Print VM arguments with java -Xlog:arguments

[iklam]

It's useful to print VM arguments to the log file, especially when you are logging several JVM invocations:

$ java -cp foo -Xlog:gc:file=a.log -Xcomp com.Foo
$ java -cp foo -Xlog:gc:file=b.log -Xint com.Foo

After a while, you may forget which process created a.log and which created b.log. Adding vm arguments into the log file will help distinguishing them:

$ java -cp foo -Xlog:gc,arguments:file=a.log -Xcomp com.Foo
$ java -cp foo -Xlog:gc,arguments:file=b.log -Xint com.Foo

$ grep jvm_args a.log b.log
a.log:[0.015s][info][arguments] jvm_args: -Xlog:gc,arguments:file=a.log -Xint
b.log:[0.001s][info][arguments] jvm_args: -Xlog:gc,arguments:file=b.log -Xcomp

Here's an example of what the log looks like:

$ java -Xlog:arguments -Xshare:on -cp ~/tmp -Dxx=yy -esa HelloWorld 1 2 3
[0.001s][info][arguments] VM Arguments:
[0.001s][info][arguments] jvm_args: -Xlog:arguments -Xshare:on -Dxx=yy -esa
[0.001s][info][arguments] java_command: HelloWorld 1 2 3
[0.001s][info][arguments] java_class_path (initial): /home/user/tmp
[0.001s][info][arguments] Launcher Type: SUN_STANDARD
Hello World

---

Progress

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Issue

• JDK-8270801: Print VM arguments with java -Xlog:arguments

Reviewers

• David Holmes (@dholmes-ora - Reviewer)
• Xin Liu (@navyxliu - Committer)
• Thomas Stuefe (@tstuefe - Reviewer)
• Yumin Qi (@yminqi - Reviewer)

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[mlbridge]

Webrevs

• 00: Full (3df0dd68)

[dholmes-ora]

Hi Ioi,

This looks good and useful. I'm surprised it hasn't been done before. :)

Thanks,
David

[openjdk]

@iklam 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:

8270801: Print VM arguments with java -Xlog:arguments

Reviewed-by: dholmes, xliu, stuefe, minqi

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 85 new commits pushed to the master branch:

• 67dc1c5: 8270837: fix typos in test TestSigParse.java
• 1d8d72d: 8270540: G1: Refactor range checking in G1BlockOffsetTablePart::block_start* to asserts
• 90c219f: 8270547: java.util.Random contains unnecessary @SuppressWarnings("exports")
• 4927ee4: 8270814: ProblemList the failing serviceability/jvmti/HeapMonitor/MyPackage/HeapMonitor* tests
• 676d425: 8270459: Conflict inlining decisions by C1/C2 with the same CompileCommand
• eab959c: 8269269: [macos11] SystemIconTest fails with ClassCastException
• e35005d: 8268773: Improvements related to: Failed to start thread - pthread_create failed (EAGAIN)
• ea77ef8: 8269725: AArch64: Add VectorMask query implementation for NEON
• 7240d67: Merge
• e104ded: 8268635: Corrupt oop in ClassLoaderData
• ... and 75 more: https://git.openjdk.java.net/jdk/compare/d6c0f5fa22d2fc07a4d8957d7ad005c03df9f8d2...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.

[navyxliu]

LGTM.

[navyxliu]

I think it better off use LogMessage to guarantee multiple-lines are not separated.
then I realize that this is very beginning, other threads haven't been up yet. so it's fine.

[tstuefe]

Very useful, Ioi!

[tstuefe]

Side note, I wish we had a similar option to print the pid (and not much else). In our proprietary port, we have a -XshowPid, which I use surprisingly often, even in scripts.

[yminqi]

LGTM.

[iklam]

Side note, I wish we had a similar option to print the pid (and not much else). In our proprietary port, we have a -XshowPid, which I use surprisingly often, even in scripts.

We have a few choices:

• -Xlog:pid : but this seems too limited to introduce a new log tag
• -Xlog:identifyprocess: print all relevant info that helps identifying the process. This would include both the arguments, the pid, and perhaps some other info as well (owner id, etc??).

If the second makes sense, we should think of a good tag name :-) I will hold the integration of the current PR for now.

[tstuefe]

Side note, I wish we had a similar option to print the pid (and not much else). In our proprietary port, we have a -XshowPid, which I use surprisingly often, even in scripts.

We have a few choices:

• -Xlog:pid : but this seems too limited to introduce a new log tag
• -Xlog:identifyprocess: print all relevant info that helps identifying the process. This would include both the arguments, the pid, and perhaps some other info as well (owner id, etc??).

If the second makes sense, we should think of a good tag name :-) I will hold the integration of the current PR for now.

After thinking about this, I think either a new "-Xlog:process", or we could just log it under "-Xlog:os". The latter could maybe benefit from some cleaning up to reduce the noise at info level.

[iklam]

Side note, I wish we had a similar option to print the pid (and not much else). In our proprietary port, we have a -XshowPid, which I use surprisingly often, even in scripts.

We have a few choices:

• -Xlog:pid : but this seems too limited to introduce a new log tag
• -Xlog:identifyprocess: print all relevant info that helps identifying the process. This would include both the arguments, the pid, and perhaps some other info as well (owner id, etc??).

If the second makes sense, we should think of a good tag name :-) I will hold the integration of the current PR for now.

After thinking about this, I think either a new "-Xlog:process", or we could just log it under "-Xlog:os". The latter could maybe benefit from some cleaning up to reduce the noise at info level.

Adding to -Xlog:os seems the right place. I tried -Xlog:os with Eclipse and it wasn't too verbose -- only about 30 lines are printed.

I filed https://bugs.openjdk.java.net/browse/JDK-8270865

[iklam]

Thanks @navyxliu @tstuefe @dholmes-ora @yminqi for the review.
/integrate

[openjdk]

Going to push as commit f8ec3b6.
Since your change was applied there have been 89 commits pushed to the master branch:

• a5c9094: Merge
• 2dddcce: 8270858: Problem List java/awt/Window/MultiWindowApp/MultiWindowAppTest.java on Linux
• 1350e2b: 8270556: Exclude security/infra/java/security/cert/CertPathValidator/certification/LetsEncryptCA
• 58f1ada: 8269636: Change outputStream's print_raw() and print_raw_cr() second parameter to size_t type
• 67dc1c5: 8270837: fix typos in test TestSigParse.java
• 1d8d72d: 8270540: G1: Refactor range checking in G1BlockOffsetTablePart::block_start* to asserts
• 90c219f: 8270547: java.util.Random contains unnecessary @SuppressWarnings("exports")
• 4927ee4: 8270814: ProblemList the failing serviceability/jvmti/HeapMonitor/MyPackage/HeapMonitor* tests
• 676d425: 8270459: Conflict inlining decisions by C1/C2 with the same CompileCommand
• eab959c: 8269269: [macos11] SystemIconTest fails with ClassCastException
• ... and 79 more: https://git.openjdk.java.net/jdk/compare/d6c0f5fa22d2fc07a4d8957d7ad005c03df9f8d2...master

Your commit was automatically rebased without conflicts.

[openjdk]

@iklam Pushed as commit f8ec3b6.

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