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

8313798: [aarch64] sun/tools/jhsdb/HeapDumpTestWithActiveProcess.java sometimes times out on aarch64 #15183

Closed
wants to merge 1 commit into from

Conversation

plummercj
Copy link
Contributor

@plummercj plummercj commented Aug 7, 2023

Make sure when walking the stack that the "sender" frame is not at a lower or the same address as the current frame, which can result in an infinite loop.

Tested with tier1 and stress testing sun/tools/jhsdb and hotspot/jtreg/serviceability/sa tests.


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-8313798: [aarch64] sun/tools/jhsdb/HeapDumpTestWithActiveProcess.java sometimes times out on aarch64 (Bug - P4)

Reviewers

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.org/jdk.git pull/15183/head:pull/15183
$ git checkout pull/15183

Update a local copy of the PR:
$ git checkout pull/15183
$ git pull https://git.openjdk.org/jdk.git pull/15183/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 15183

View PR using the GUI difftool:
$ git pr show -t 15183

Using diff file

Download this PR as a diff file:
https://git.openjdk.org/jdk/pull/15183.diff

Webrev

Link to Webrev Comment

@bridgekeeper
Copy link

bridgekeeper bot commented Aug 7, 2023

👋 Welcome back cjplummer! 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 changed the title 8313798 8313798: [aarch64] sun/tools/jhsdb/HeapDumpTestWithActiveProcess.java sometimes times out on aarch64 Aug 7, 2023
@openjdk openjdk bot added the rfr Pull request is ready for review label Aug 7, 2023
@openjdk
Copy link

openjdk bot commented Aug 7, 2023

@plummercj 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.

@openjdk openjdk bot added the serviceability serviceability-dev@openjdk.org label Aug 7, 2023
@mlbridge
Copy link

mlbridge bot commented Aug 7, 2023

Webrevs

Copy link
Contributor

@kevinjwalls kevinjwalls left a comment

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Looks good to me, although do you think it could return null rather than throw a RuntimeException? Concerned we might not always want the Tool to fail and end there.

Copy link
Contributor

@sspitsyn sspitsyn left a comment

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Looks good.
Thanks,
Serguei

@openjdk
Copy link

openjdk bot commented Aug 10, 2023

@plummercj 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:

8313798: [aarch64] sun/tools/jhsdb/HeapDumpTestWithActiveProcess.java sometimes times out on aarch64

Reviewed-by: kevinw, sspitsyn

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 46 new commits pushed to the master branch:

  • 79be8d9: 8312259: StatusResponseManager unused code clean up
  • 1875b28: 8314061: [JVMCI] DeoptimizeALot stress logic breaks deferred barriers
  • bd1b942: 8313905: Checked_cast assert in CDS compare_by_loader
  • 9b53251: 8313654: Test WaitNotifySuspendedVThreadTest.java timed out
  • e7c83ea: 8312194: test/hotspot/jtreg/applications/ctw/modules/jdk_crypto_ec.java cannot handle empty modules
  • 23fe2ec: 8313616: support loading library members on AIX in os::dll_load
  • f47767f: 8313882: Fix -Wconversion warnings in runtime code
  • 0cb9ab0: 8313239: InetAddress.getCanonicalHostName may return ip address if reverse lookup fails
  • 028b3ae: 8313874: JNI NewWeakGlobalRef throws exception for null arg
  • 83adaf5: 8313421: [JVMCI] avoid locking class loader in CompilerToVM.lookupType
  • ... and 36 more: https://git.openjdk.org/jdk/compare/87b08b6e0192d88025c2275c7dd2c4bdecda58e8...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 Pull request is ready to be integrated label Aug 10, 2023
@theRealAph
Copy link
Contributor

I wonder what triggers this problem. Maybe there's an underlying bug, or maybe it's just to do with AArch64's weakly-consistent memory model.

@plummercj
Copy link
Contributor Author

Looks good to me, although do you think it could return null rather than throw a RuntimeException? Concerned we might not always want the Tool to fail and end there.

I chose throwing an exception, because this is what more commonly happens when you get a bad frame. You end up with some sort of AddressException, NPE, or a WrongTypeException while exploring garbage. See JDK-8313800, especially the following comment:

There are also other exceptions being thrown with similar stack traces (they didn't cause the JDK-8313798 timeout because an exception was thrown instead of getting in an infinite loop):

@plummercj
Copy link
Contributor Author

plummercj commented Aug 10, 2023

I wonder what triggers this problem. Maybe there's an underlying bug, or maybe it's just to do with AArch64's weakly-consistent memory model.

Yes, you are correct, and I already filed JDK-8313800. As noted in this JDK-8313800, you really shouldn't ever see issues at this point in the stack walk:

Note, usually stack walking issues with an active thread are with the topmost frame (the first frame that is visited), because it might be in an inconsistent state (not fully pushed or popped). If the state of the first frame is valid, then walking the rest of the stack should have no issues. But in all the above cases we eventually run into an issue with a frame higher up the stack, so this suggests that the stack walking code is broken in certain situations. Basically there is a frame somewhere in the middle of the stack that the stack walking code doesn't know how to get past. This seems to be unique to aarch64.

This could be SA not understanding how to properly walk the frame. For example, maybe an issue like JDK-8247351, which has been fixed.

That being said, the fix for this PR is still warranted because it could happen if the first frame is not in a valid state.

@plummercj
Copy link
Contributor Author

Thanks for the reviews Serguei and Kevin!

/integrate

@openjdk
Copy link

openjdk bot commented Aug 11, 2023

Going to push as commit 8f1c134.
Since your change was applied there have been 55 commits pushed to the master branch:

  • 1232677: 8313244: NM flags handling in configure process
  • 6ffc032: 8314113: G1: Remove unused G1CardSetInlinePtr::card_at
  • 62adeb0: 8311648: Refactor the Arena/Chunk/ChunkPool interface
  • 43462a3: 8313224: Avoid calling JavaThread::current() in MemAllocator::Allocation constructor
  • 9abb2a5: 8312461: JNI warnings in SunMSCApi provider
  • 42758cb: 8312882: Update the CONTRIBUTING.md with pointers to lifecycle of a PR
  • 88b4e3b: 8304292: Memory leak related to ClassLoader::update_class_path_entry_list
  • 6f5c903: 8313899: JVMCI exception Translation can fail in TranslatedException.
  • d97de82: 8313633: [macOS] java/awt/dnd/NextDropActionTest/NextDropActionTest.java fails with java.lang.RuntimeException: wrong next drop action!
  • 79be8d9: 8312259: StatusResponseManager unused code clean up
  • ... and 45 more: https://git.openjdk.org/jdk/compare/87b08b6e0192d88025c2275c7dd2c4bdecda58e8...master

Your commit was automatically rebased without conflicts.

@openjdk openjdk bot added the integrated Pull request has been integrated label Aug 11, 2023
@openjdk openjdk bot closed this Aug 11, 2023
@openjdk openjdk bot removed ready Pull request is ready to be integrated rfr Pull request is ready for review labels Aug 11, 2023
@openjdk
Copy link

openjdk bot commented Aug 11, 2023

@plummercj Pushed as commit 8f1c134.

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

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Labels
integrated Pull request has been integrated serviceability serviceability-dev@openjdk.org
4 participants