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

8310264: In PhaseChaitin::Split defs and phis are leaked #14530

Closed
wants to merge 7 commits into from

Conversation

jdksjolen
Copy link
Contributor

@jdksjolen jdksjolen commented Jun 17, 2023

Hi,

defs and phis are leaked as they are resource allocated but not protected by a ResourceMark. The intention might have been for these to also live in the split_arena.. This change is the most conservative one, however, and does fix the memory leak.

Please consider, thanks.

Johan


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-8310264: In PhaseChaitin::Split defs and phis are leaked (Bug - P4)

Reviewers

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.org/jdk.git pull/14530/head:pull/14530
$ git checkout pull/14530

Update a local copy of the PR:
$ git checkout pull/14530
$ git pull https://git.openjdk.org/jdk.git pull/14530/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 14530

View PR using the GUI difftool:
$ git pr show -t 14530

Using diff file

Download this PR as a diff file:
https://git.openjdk.org/jdk/pull/14530.diff

Webrev

Link to Webrev Comment

@bridgekeeper
Copy link

bridgekeeper bot commented Jun 17, 2023

👋 Welcome back jsjolen! 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 Pull request is ready for review label Jun 17, 2023
@openjdk
Copy link

openjdk bot commented Jun 17, 2023

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

  • hotspot-compiler

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-compiler hotspot-compiler-dev@openjdk.org label Jun 17, 2023
@mlbridge
Copy link

mlbridge bot commented Jun 17, 2023

Webrevs

Copy link
Member

@TobiHartmann TobiHartmann 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.

@openjdk
Copy link

openjdk bot commented Jun 19, 2023

@jdksjolen 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:

8310264: In PhaseChaitin::Split defs and phis are leaked

Reviewed-by: thartmann, chagedorn, kvn

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 186 new commits pushed to the master branch:

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 Jun 19, 2023
Copy link
Member

@chhagedorn chhagedorn 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! I'm wondering, why we don't stack allocate both Node_List instead of new Node_List(). But regardless of that, we should indeed add a ResourceMark.

@shipilev
Copy link
Member

shipilev commented Jun 19, 2023

Looking at f0d08c0 -- it would seem that def and phi just missed the allocation in split_arena? I think it would a cleaner/safer to change def/phi to be allocated in split_arena, rather than doing the blank ResourceMark here. Are we sure nothing RA-allocated is used after we leave Split?

@jdksjolen
Copy link
Contributor Author

Hi,

In pursuit of answering your questions I saw some more opportunities for improvement. I did end up removing the ResourceMark as the size of Split makes it difficult to see whether it changes something that's used later on or not.

First of all, the VectorSets allocated their elements on the arena, but themselves on the resource area, this was another unhandled memory leak. I fixed that by allocating the VSets themselves on the arena, also. This removes a leak of spill_cnt*56 bytes.

Second of all @shipilev asked a good question, and I think that we can move defs and phis into the arena. I was worried about the sizes of these arrays being quite large and thus triggering a lot of reallocations, but they're typically quite small (I measured) while sometimes reaching to defs being 256 and phis 512 elements. I picked a conservative lower bound of 8/16.

For what it's worth, the number of VectorSets seems to strongly correlate with the size of the sets. a future RFE might make these larger by default. All of these measurements are done by running a Spring Hello World-app as a substitute for a 'real'/'typical' workload.

Copy link
Member

@TobiHartmann TobiHartmann left a comment

Choose a reason for hiding this comment

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

Good catch! Looks good to me otherwise.

Comment on lines 574 to 575
Node_List defs{split_arena, 8};
Node_List phis{split_arena, 16};
Copy link
Member

Choose a reason for hiding this comment

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

Why do you use aggregate initialization instead of constructor invocation here?

Copy link
Contributor Author

Choose a reason for hiding this comment

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

This will call the constructor, and has since C++11 I believe. However, I'm clearly being inconsistent here and with the VectorSet change above. There's no reason that I picked brace initializer other than it being the 'modern' way: https://isocpp.github.io/CppCoreGuidelines/CppCoreGuidelines#Res-list

I'll revert this change and use regular parens to be more stylistically consistent.

Copy link
Contributor Author

Choose a reason for hiding this comment

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

Looking at https://github.com/openjdk/jdk/blob/master/doc/hotspot-style.md "uniform initialization", it's OK to use.

Copy link
Member

Choose a reason for hiding this comment

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

Thanks for the background, I wasn't aware of that. I don't have a strong opinion but consistency in the same area would be nice.

Copy link
Contributor

Choose a reason for hiding this comment

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

Please, change to normal (). Using '{}' is very confusing for not modern C++ experts and affects maintainability of this code.

Copy link
Contributor Author

Choose a reason for hiding this comment

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

Thanks for the input, reverted to ().

@jdksjolen
Copy link
Contributor Author

@chhagedorn , @TobiHartmann , would you mind re-approving this PR? Thank you.

Copy link
Member

@chhagedorn chhagedorn left a comment

Choose a reason for hiding this comment

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

Update looks good!

Copy link
Member

@TobiHartmann TobiHartmann 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 too.

Copy link
Contributor

@vnkozlov vnkozlov left a comment

Choose a reason for hiding this comment

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

Good.

@jdksjolen
Copy link
Contributor Author

Thank you.

/integrate

@openjdk
Copy link

openjdk bot commented Jun 28, 2023

Going to push as commit 02b17d7.
Since your change was applied there have been 191 commits pushed to the master branch:

  • a63afa4: 8294427: Check boxes and radio buttons have rendering issues on Windows in High DPI env
  • 3df36c4: 8310061: Note if implicit annotation processing is being used
  • da0f832: 8310606: Fix signed integer overflow, part 3
  • f0c2f09: 8296972: [macos13] java/awt/Frame/MaximizedToIconified/MaximizedToIconified.java: getExtendedState() != 6 as expected.
  • 9f46fc2: 8310906: Fix -Wconversion warnings in runtime, oops and some code header files.
  • 7fffdb5: 8310405: Linker.Option.firstVariadicArg should specify which index values are valid
  • b6c789f: 8309140: ResourceHashtable failed "assert(~(_allocation_t[0] | allocation_mask) == (uintptr_t)this) failed: lost resource object"
  • 9f98136: 6956385: URLConnection.getLastModified() leaks file handles for jar:file and file: URLs
  • 46e4ee1: 8310974: NMT: Arena diffs miss the scale
  • f17bfee: 8311034: Fix typo in javac man page
  • ... and 181 more: https://git.openjdk.org/jdk/compare/955fc2fabafc4c4d79d137bf86194228d5cf8ad8...master

Your commit was automatically rebased without conflicts.

@openjdk openjdk bot added the integrated Pull request has been integrated label Jun 28, 2023
@openjdk openjdk bot closed this Jun 28, 2023
@openjdk openjdk bot removed ready Pull request is ready to be integrated rfr Pull request is ready for review labels Jun 28, 2023
@openjdk
Copy link

openjdk bot commented Jun 28, 2023

@jdksjolen Pushed as commit 02b17d7.

💡 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
hotspot-compiler hotspot-compiler-dev@openjdk.org integrated Pull request has been integrated
5 participants