[ExecuTorch][WebGPU] Optimize reduction-family kernels to cooperative shared-memory#21225
Open
JCNTH wants to merge 1 commit into
Open
[ExecuTorch][WebGPU] Optimize reduction-family kernels to cooperative shared-memory#21225JCNTH wants to merge 1 commit into
JCNTH wants to merge 1 commit into
Conversation
🔗 Helpful Links🧪 See artifacts and rendered test results at hud.pytorch.org/pr/pytorch/executorch/21225
Note: Links to docs will display an error until the docs builds have been completed. ❗ 1 Active SEVsThere are 1 currently active SEVs. If your PR is affected, please view them below: ❌ 46 New Failures, 3 Unrelated FailuresAs of commit 1880c84 with merge base 266e0dc ( NEW FAILURES - The following jobs have failed:
FLAKY - The following jobs failed but were likely due to flakiness present on trunk:
BROKEN TRUNK - The following job failed but were present on the merge base:👉 Rebase onto the `viable/strict` branch to avoid these failures
This comment was automatically generated by Dr. CI and updates every 15 minutes. |
This was referenced Jul 22, 2026
This was referenced Jul 22, 2026
meta-cla
Bot
added
the
CLA Signed
This PR needs a
|
psiddh
approved these changes
Jul 23, 2026
psiddh
left a comment
psiddh
left a comment
Contributor
There was a problem hiding this comment.
Approving full WebGPU stack
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Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be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.
Stack from ghstack (oldest at bottom):
Problem: The reduction ops (amax/amin/argmax/sum/mean), softmax/log_softmax, and native_group_norm's reduce pass used naive one-thread-per-row serial loops — far below Vulkan's optimization level, where backends/vulkan/runtime/graph/ops/glsl/reduce.glsl uses a cooperative shared-memory reduction.
Solution: Rewrite each to Vulkan's cooperative design — one workgroup per reduction row/group, each thread reduces a strided slice into a workgroup shared array, thread 0 aggregates the partials. Dispatch changed to one workgroup per row. argmax preserves torch's first-index tie-break; softmax keeps numerical stability + the log variant.
Differential Revision: D112257649