[SYCLTLA] Fix FlashAttention FWD performance on PVC #2415
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Pull request overview
Fixes a performance regression on PVC by correcting a missing else statement that caused a kernel to be launched twice. The PR also adds missing CUTLASS_DEVICE annotations to device functions.
- Fixed conditional branching for kernel launch based on subgroup size
- Added
CUTLASS_DEVICEannotations to device-only functions
Reviewed changes
Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.
| File | Description |
|---|---|
| src/ATen/native/transformers/xpu/flash_attn/sycltla/mha_fwd.cpp | Fixed missing else statement that was causing duplicate kernel launches |
| src/ATen/native/transformers/xpu/flash_attn/sycltla/kernel/xe_sdpa_fwd_bshd.h | Added CUTLASS_DEVICE annotations to device functions |
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LuFinch
changed the title
EikanWang
approved these changes
Nov 28, 2025
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Author
|
Can we merge this PR? |
Contributor
|
Sure. |
EikanWang
approved these changes
Nov 28, 2025
EikanWang
approved these changes
Nov 30, 2025
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I missed a
elsewhen launch kernel so that it launchs kernel twice on PVC..