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
8267703: runtime/cds/appcds/cacheObject/HeapFragmentationTest.java crashed with OutOfMemory #4225
Closed
Closed
Changes from all commits
Commits
Show all changes
3 commits
Select commit
Hold shift + click to select a range
File filter
Filter by extension
Conversations
Failed to load comments.
Jump to
Jump to file
Failed to load files.
Diff view
Diff view
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
There was a problem hiding this comment.
Choose a reason for hiding this comment
The reason will be displayed to describe this comment to others. Learn more.
That's pre-existing, but this will change the number of active workers for the rest of the garbage collection. That made some sense previously as
G1FullCollector::calc_active_workers()
typically was very aggressive, but now it may limit other phases a bit, particularly marking which distributes on a per-reference basis.Overall it might not make much difference though as we are talking about the very little occupied heap case.
I.e. some rough per-full gc phase might be better and might be derived easily too.
There was a problem hiding this comment.
Choose a reason for hiding this comment
The reason will be displayed to describe this comment to others. Learn more.
This was one of the reasons I went with using "just used regions" and skipping the part that each worker will handle a set of regions. In most cases looking at used regions will not limit the workers much, and if it does we don't have much work to do. I've done some benchmarking and not seen any significant regressions with this patch. The biggest problem was not using enough workers for the bitmap-work.
Calculating workers per phase might be a good improvement to consider, but that would require some more refactoring.
There was a problem hiding this comment.
Choose a reason for hiding this comment
The reason will be displayed to describe this comment to others. Learn more.
Okay. If you think it would take too long, please file an issue for per-phase thread sizing in parallel gc then (if there isn't).
There was a problem hiding this comment.
Choose a reason for hiding this comment
The reason will be displayed to describe this comment to others. Learn more.
I'll file an RFE.