Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

8268906: gc/g1/mixedgc/TestOldGenCollectionUsage.java assumes that GCs take 1ms minimum #4531

Conversation

tschatzl
Copy link
Contributor

@tschatzl tschatzl commented Jun 18, 2021

Hi,

can I have reviews for this change to a test that incorrectly assumed that GCs take 1ms minimum?

At the end of the test, MXBeans' getCollectionTime() is compared against one taken two gcs earlier. If these two gcs are very short, getCollectionTime() returns the same value as before because its resolution is 1ms.

The getCollectionTime() documentation states:

Returns the approximate accumulated collection elapsed time in milliseconds. This method returns -1 if the collection elapsed time is undefined for this collector.

The Java virtual machine implementation may use a high resolution timer to measure the elapsed time. This method may return the same value even if the collection count has been incremented if the collection elapsed time is very short.

Which is what the test tested

Testing: test does not fail any more after some VM hack so that getCollectionTime() returns very low values.

Thanks,
Thomas


Progress

  • Change must not contain extraneous whitespace
  • Commit message must refer to an issue
  • Change must be properly reviewed

Issue

  • JDK-8268906: gc/g1/mixedgc/TestOldGenCollectionUsage.java assumes that GCs take 1ms minimum

Reviewers

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.java.net/jdk pull/4531/head:pull/4531
$ git checkout pull/4531

Update a local copy of the PR:
$ git checkout pull/4531
$ git pull https://git.openjdk.java.net/jdk pull/4531/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 4531

View PR using the GUI difftool:
$ git pr show -t 4531

Using diff file

Download this PR as a diff file:
https://git.openjdk.java.net/jdk/pull/4531.diff

@bridgekeeper
Copy link

@bridgekeeper bridgekeeper bot commented Jun 18, 2021

👋 Welcome back tschatzl! 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 openjdk bot added the rfr label Jun 18, 2021
@openjdk
Copy link

@openjdk openjdk bot commented Jun 18, 2021

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

  • hotspot-gc

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.

@openjdk openjdk bot added the hotspot-gc label Jun 18, 2021
@mlbridge
Copy link

@mlbridge mlbridge bot commented Jun 18, 2021

Webrevs

Copy link

@kimbarrett kimbarrett left a comment

Looks good.

@openjdk
Copy link

@openjdk openjdk bot commented Jun 18, 2021

@tschatzl 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:

8268906: gc/g1/mixedgc/TestOldGenCollectionUsage.java assumes that GCs take 1ms minimum

Reviewed-by: kbarrett, ayang, lkorinth

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 153 new commits pushed to the master branch:

  • ee0247f: 8263461: jdk/jfr/event/gc/detailed/TestEvacuationFailedEvent.java uses wrong mechanism to cause evacuation failure
  • 3ad20fc: 8269571: NMT should print total malloc bytes and invocation count
  • b969136: 8245877: assert(_value != __null) failed: resolving NULL _value in JvmtiExport::post_compiled_method_load
  • ee526a2: Merge
  • 0d745ae: 8269034: AccessControlException for SunPKCS11 daemon threads
  • d042029: 8269529: javax/swing/reliability/HangDuringStaticInitialization.java fails in Windows debug build
  • 401cb0a: 8269232: assert(!is_jweak(handle)) failed: wrong method for detroying jweak
  • b8a16e9: 8268884: C2: Compile::remove_speculative_types must iterate top-down
  • 25f9f19: 8249646: Runtime.exec(String, String[], File) documentation contains literal {@link ...}
  • 0d83dc2: 8268699: Shenandoah: Add test for JDK-8268127
  • ... and 143 more: https://git.openjdk.java.net/jdk/compare/5ae9a12858a20361c163e1dfe6b67970f27e4e40...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.

@openjdk openjdk bot added the ready label Jun 18, 2021
@tschatzl
Copy link
Contributor Author

@tschatzl tschatzl commented Jun 21, 2021

Thanks @kimbarrett for your review.

Copy link
Contributor

@lkorinth lkorinth left a comment

Looks good to me.

@tschatzl
Copy link
Contributor Author

@tschatzl tschatzl commented Jun 30, 2021

Thanks @kimbarrett @lkorinth @albertnetymk for your reviews.

/integrate

@openjdk
Copy link

@openjdk openjdk bot commented Jun 30, 2021

Going to push as commit a0f32cb.
Since your change was applied there have been 153 commits pushed to the master branch:

  • ee0247f: 8263461: jdk/jfr/event/gc/detailed/TestEvacuationFailedEvent.java uses wrong mechanism to cause evacuation failure
  • 3ad20fc: 8269571: NMT should print total malloc bytes and invocation count
  • b969136: 8245877: assert(_value != __null) failed: resolving NULL _value in JvmtiExport::post_compiled_method_load
  • ee526a2: Merge
  • 0d745ae: 8269034: AccessControlException for SunPKCS11 daemon threads
  • d042029: 8269529: javax/swing/reliability/HangDuringStaticInitialization.java fails in Windows debug build
  • 401cb0a: 8269232: assert(!is_jweak(handle)) failed: wrong method for detroying jweak
  • b8a16e9: 8268884: C2: Compile::remove_speculative_types must iterate top-down
  • 25f9f19: 8249646: Runtime.exec(String, String[], File) documentation contains literal {@link ...}
  • 0d83dc2: 8268699: Shenandoah: Add test for JDK-8268127
  • ... and 143 more: https://git.openjdk.java.net/jdk/compare/5ae9a12858a20361c163e1dfe6b67970f27e4e40...master

Your commit was automatically rebased without conflicts.

@openjdk openjdk bot closed this Jun 30, 2021
@openjdk openjdk bot added integrated and removed ready rfr labels Jun 30, 2021
@openjdk
Copy link

@openjdk openjdk bot commented Jun 30, 2021

@tschatzl Pushed as commit a0f32cb.

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

@tschatzl tschatzl deleted the submit/8268906-collector-has-not-run-some-more branch Jun 30, 2021
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Labels
hotspot-gc integrated
4 participants