Use small page size/flags for Sparse Virtual Memory - #7164
Merged
Conversation
Contributor
Author
|
@amicic please review. |
amicic
approved these changes
Oct 30, 2023
Contributor
Author
|
@babsingh Would you please help to merge this change?
|
Contributor
|
https://github.com/eclipse/omr/blob/master/CONTRIBUTING.md#commit-guidelines The title (first line) shouldn't end with a period: Otherwise, the changes LGTM. |
Currently Sparse Virtual Memory uses page size Object Heap is allocated with. We want to use small pages for Sparse Heap always regardless. Also Sparse Virtual Memory uses page flags "requested" for Object Heap. This is the bug. Page flags should be paired with the page size. Please note, that current MM_SparseVirtualMemory implementation can use double mapping instead of off-heap. This is an experimental feature never used in the code and not planned to be used. This feature uses hidden assumption that memory page size/flags should be the same for Object and Sparse heaps. This PR can break it potentially in the case memory page settings in the Object Heap and Sparse heap are different. We are going to be aware about this if we need another round of experimental testing with double mapping support. Signed-off-by: Dmitri Pivkine <Dmitri_Pivkine@ca.ibm.com>
dmitripivkine
changed the title
Contributor
Author
Sorry, fixed. Thank you! |
Contributor
|
jenkins build all |
This file contains hidden or 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
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
3 participants
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Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be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.
Currently Sparse Virtual Memory uses page size Object Heap is allocated with. We want to use small pages for Sparse Heap always regardless. Also Sparse Virtual Memory uses page flags "requested" for Object Heap. This is the bug. Page flags should be paired with the page size.
Please note, that current MM_SparseVirtualMemory implementation can use double mapping instead of off-heap. This is an experimental feature never used in the code and not planned to be used. This feature uses hidden assumption that memory page size/flags should be the same for Object and Sparse heaps. This PR can break it potentially in the case memory page settings in the Object Heap and Sparse heap are different. We are going to be aware about this if we need another round of experimental testing with double mapping support.