[Fuzzer] Optimize UpdateFeatureFrequency #65288
Merged
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
Instead of a linear scan, use a bitset to track rarity of features. This improves fuzzer throughput rather dramatically (close to 2x) in early exploratory phases; in steady state this seems to improve fuzzing throughput by ~15% according to perf. The benchmarks are done on an executable with ~100k features, so the results may change based on the executable that's being fuzzed. kFeatureSetSize is 2M so the bitset is adding 256 KB to sizeof(InputCorpus), but this should be fine since there's already three arrays indexed by feature index for a total of 200 MB.
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Outdated suggestions cannot be applied.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.
Instead of a linear scan, use a bitset to track rarity of features. This improves fuzzer throughput rather dramatically (close to 2x) in early exploratory phases; in steady state this seems to improve fuzzing throughput by ~15% according to perf.
The benchmarks are done on an executable with ~100k features, so the results may change based on the executable that's being fuzzed.
kFeatureSetSize is 2M so the bitset is adding 256 KB to sizeof(InputCorpus), but this should be fine since there's already three arrays indexed by feature index for a total of 200 MB.