[Fix][ROCm] Remove unused variables to fix build error on GFX11/12 #19891
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Signed-off-by: Hosang Yoon <[email protected]>
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Summary of Changes
Hello @hyoon1, I'm Gemini Code Assist1! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!
This pull request addresses a critical build failure on AMD Radeon GPUs (GFX11/12) by removing specific unused variables within the custom paged attention kernel. The changes are purely for compilation success and code cleanliness, with no impact on the functional behavior or performance of the existing attention mechanism.
Highlights
- Build Fix for ROCm: Removed unused local variables (
lane4idandkglobal_token_idx) from the custom paged attention kernel incsrc/rocm/attention.cu. This resolves a build error specifically on AMD Radeon GPUs (GFX11/12) that was introduced by a previous PR. - Code Clean-up: Improved code hygiene by removing variables that were declared but not utilized, ensuring the codebase remains lean and maintainable. The changes have no functional impact.
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Code Review
The pull request removes unused variables in the custom paged attention kernel to fix a build error on AMD Radeon GPUs (gfx11/12). The changes involve deleting unused local variables in the paged_attention_ll4mi_QKV_mfma16_kernel function within the csrc/rocm/attention.cu file. The variables lane4id and kglobal_token_idx are removed as they are not utilized within the kernel's logic.
| @@ -1598,7 +1598,6 @@ __launch_bounds__(NUM_THREADS, 3) void paged_attention_ll4mi_QKV_mfma16_kernel( | |||
| const int warpid = threadIdx.x / WARP_SIZE; | |||
| const int laneid = threadIdx.x % WARP_SIZE; | |||
| const int lane2id = laneid % 2; | |||
| const int lane4id = laneid % 4; | |||
| const int lane16id = laneid % 16; | |||
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This variable is no longer used and can be removed.
| @@ -1745,7 +1744,6 @@ __launch_bounds__(NUM_THREADS, 3) void paged_attention_ll4mi_QKV_mfma16_kernel( | |||
| const cache_t* k_ptr2 = k_ptr + kblock_number * kv_block_stride; | |||
| const int klocal_token_idx = | |||
| TOKENS_PER_WARP * warpid + token_depth * 16 + lane16id; | |||
| const int kglobal_token_idx = partition_start_token_idx + klocal_token_idx; | |||
| const int kphysical_block_offset = klocal_token_idx % BLOCK_SIZE; | |||
| const cache_t* k_ptr3 = k_ptr2 + kphysical_block_offset * KX; | |||
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This variable is no longer used and can be removed.
github-actions
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Retry the failed tests. Curious how the breakage was landed. |
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Oh, my PR didn't cover the old arches... sorry. |
Essential Elements of an Effective PR Description Checklist
supported_models.mdandexamplesfor a new model.Purpose
After this PR: #19796 build is failing on AMD Radeon GPU (gfx11/12)
Removed unused variables from custom paged attention kernel to fix build error
Test Plan
python setup.py develop
Test Result
Build succeeded after removing unused variables.
No functional changes.
(Optional) Documentation Update