feat(ext4): pack metadata + larger flex group on rootfs mkfs#2566
Closed
ValentaTomas wants to merge 1 commit intomainfrom
Closed
feat(ext4): pack metadata + larger flex group on rootfs mkfs#2566ValentaTomas wants to merge 1 commit intomainfrom
ValentaTomas wants to merge 1 commit intomainfrom
Conversation
Pass -G 64 (flex group size, default 16) and -E packed_meta_blocks=1 to mkfs.ext4. Both options improve spatial clustering of ext4 metadata on disk: - -G 64 packs inode tables and bitmaps for 64 block groups into one contiguous run instead of 16, so small-file metadata churn is more likely to dirty blocks within the same 4 MiB GCS chunk. - packed_meta_blocks places all metadata at the start of the disk so superblock / group descriptor / inode table / bitmap dirties cluster together rather than being interleaved with data regions. Net effect: fewer distinct 4 MiB chunks per snapshot diff, fewer GCS round-trips on cold resume. mkfs-time only; affects newly-built bases.
PR SummaryMedium Risk Overview Reviewed by Cursor Bugbot for commit 5c017fc. Bugbot is set up for automated code reviews on this repo. Configure here. |
![gemini-code-assist[bot]](https://avatars.githubusercontent.com/in/956858?s=60&v=4){kind=small}
❌ 98 Tests Failed:
View the full list of 104 ❄️ flaky test(s)
To view more test analytics, go to the Test Analytics Dashboard |
CI Feedback 🧐A test triggered by this PR failed. Here is an AI-generated analysis of the failure:
|
Member
Author
|
Close for now, will reopen after measuring later. |
Member
Author
|
Close for now, will reopen after measuring later. |
Member
Author
|
Close for now, will reopen after measuring later. |
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
2 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.
Pass
-G 64and-E packed_meta_blocks=1tomkfs.ext4on rootfs creation. Both options cluster ext4 metadata more tightly on disk so small-file metadata dirties land in fewer 4 MiB GCS chunks per snapshot.mkfs-time only, no semantic change. Pairs with #2563 (inline_data).