sstable: perf improvement for ResetForReuse #4081
Merged
Conversation
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 change is |
Resetting iterators takes a non-trivial amount of time (15% in the RandSeekInSST benchmark). Most of it is because we're copying fairly large structures by value. We change `ResetForReuse` to reset the iterator in-place, and we use an unsafe trick to clear out only a section of `singleLevelIterator`. Benchmark (baseline includes a few other in-flight PRs): ``` name old time/op new time/op delta RandSeekInSST/v4/single-level-10 1.15µs ± 0% 1.02µs ± 1% -10.84% (p=0.001 n=7+7) RandSeekInSST/v4/two-level-10 1.99µs ± 2% 1.71µs ± 2% -13.85% (p=0.000 n=8+8) RandSeekInSST/v5/single-level-10 944ns ± 1% 823ns ± 1% -12.86% (p=0.000 n=8+8) RandSeekInSST/v5/two-level-10 1.44µs ± 1% 1.24µs ± 7% -13.79% (p=0.000 n=7+8) ```
RaduBerinde
force-pushed
the
optimizer-reset
branch
from
ca88b3b
to
e9a3844
Compare
jbowens
approved these changes
Oct 19, 2024
There was a problem hiding this comment.
Reviewed 9 of 9 files at r1, all commit messages.
Reviewable status:complete! all files reviewed, all discussions resolved (waiting on @RaduBerinde)
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
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Outdated suggestions cannot be applied.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.
Resetting iterators takes a non-trivial amount of time (15% in the
RandSeekInSST benchmark). Most of it is because we're copying fairly
large structures by value.
We change
ResetForReuseto reset the iterator in-place, and we usean unsafe trick to clear out only a section of
singleLevelIterator.Benchmark (baseline includes a few other in-flight PRs):