Repository navigation
[executorch][cuda] Test prefix-cache reuse on CudaExecutor - #24008
Merged
Merged
Conversation
Pull Request resolved: #23732 The serving runtime's opt-in prefix cache (batching::PrefixCache, enabled by `--prefix_cache_entries`) reuses KV through Session::clone_async, which on CUDA reaches CudaExecutor::clone -> SessionTable::clone -> CellCache::seq_clone. The cell layout clones by reference: the snapshot's id joins the owner bits of the source's cells below the boundary, so reuse shares the prompt's KV instead of copying it. Nothing needed to change to enable it; this adds the coverage that shows it is correct on the GPU. PrefixCacheResumesFromACapturedPrompt, on each toy artifact (dense, sparse, device_sampling): every prompt's cold generation leaves a snapshot captured at its prompt boundary. A lookup for the same prompt reuses all but its last token and one for a prompt extending it reuses the whole snapshot; both resume on the eager greedy continuation. So the clone carried the prompt's exact KV, and the source's later decode writes, padding rows and the clones' own writes did not disturb one another. ghstack-source-id: 451855087 @exported-using-ghexport Differential Revision: [D124871960](https://our.internmc.facebook.com/intern/diff/D124871960/)
🔗 Helpful Links🧪 See artifacts and rendered test results at hud.pytorch.org/pr/pytorch/executorch/24008
Note: Links to docs will display an error until the docs builds have been completed. ⏳ No Failures, 189 PendingAs of commit d81042b with merge base 897d28f ( This comment was automatically generated by Dr. CI and updates every 15 minutes. |
meta-cla
Bot
added
the
CLA Signed
shoumikhin
approved these changes
Oct 20, 2026
This branch was successfully deployed
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.
This PR was created by the merge bot to help merge the original PR into the main branch.
ghstack PR number: #23732 by @Gasoonjia
^ Please use this as the source of truth for the PR details, comments, and reviews
ghstack PR base: https://github.com/pytorch/executorch/tree/gh/Gasoonjia/48/base
ghstack PR head: https://github.com/pytorch/executorch/tree/gh/Gasoonjia/48/head
Merge bot PR base: https://github.com/pytorch/executorch/tree/gh/Gasoonjia/47/orig
Merge bot PR head: https://github.com/pytorch/executorch/tree/gh/Gasoonjia/48/orig
Differential Revision: D124871960
@diff-train-skip-merge