GH-48004: [C++][Parquet] Fix hang in ColumnReader benchmark #48005
+15
−11
Conversation
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
The benchmark was instantiating the ColumnReader with less values than it would later attempt to read. The `ReadBatch` method would then return 0 prematurely and the loop would never progress.
|
@ursabot please benchmark lang=C++ |
|
Benchmark runs are scheduled for commit 2bba103. Watch https://buildkite.com/apache-arrow and https://conbench.ursa.dev for updates. A comment will be posted here when the runs are complete. |
github-actions
bot
added
Component: Parquet
Component: C++
awaiting review
pitrou
commented
Oct 30, 2025
Comment on lines
206
to
+207
| std::shared_ptr<Int64Reader> reader = | ||
| BuildReader(src, state.range(1), codec, schema.get()); | ||
| BuildReader(src, kNumValues, codec, schema.get()); |
There was a problem hiding this comment.
This is the fix: we were instantiating the ColumnReader with the read batch size (state.range(1)) instead of the total number of values (state.range(0)).
github-actions
bot
added
awaiting committer review
|
Thanks for your patience. Conbench analyzed the 4 benchmarking runs that have been run so far on PR commit 2bba103. There were 80 benchmark results indicating a performance regression:
The full Conbench report has more details. |
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Outdated suggestions cannot be applied.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.
Rationale for this change
The benchmark was instantiating the
ColumnReaderwith less values than it would later attempt to read. TheReadBatchmethod would then return 0 prematurely and the loop would never progress.Are these changes tested?
Manually and by continuous benchmarking.
Are there any user-facing changes?
No.