[CK] fix moe memset size which is bigger than alloc#5225
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Mar 16, 2026
[CK] fix moe memset size which is bigger than alloc ## Motivation Fix an out-of-bounds hipMemsetAsync in DeviceMoeGemmBlockScale that crashes split-K MOE GEMM with "HIP runtime error: invalid argument". When KBatch > 1, the invoker zeroes the output buffer using arg.M * arg.N as the byte count. However, arg.M is the padded sorted-token-id length from MOE routing, which can be much larger than the actual output allocation (NumTokens * TopK * N). This causes hipMemsetAsync to write beyond the buffer, and the silently-swallowed HIP error propagates to the subsequent kernel launch via hipGetLastError(). This patch replaces arg.M with arg.NumTokens * arg.TopK so the memset matches the actual output size. ## Technical Details <!-- Explain the changes along with any relevant GitHub links. --> ## Test Plan <!-- Explain any relevant testing done to verify this PR. --> ## Test Result <!-- Briefly summarize test outcomes. --> ## Submission Checklist - [x] Look over the contributing guidelines at https://github.com/ROCm/ROCm/blob/develop/CONTRIBUTING.md#pull-requests.
jovanau
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Mar 19, 2026
## Motivation Fix an out-of-bounds hipMemsetAsync in DeviceMoeGemmBlockScale that crashes split-K MOE GEMM with "HIP runtime error: invalid argument". When KBatch > 1, the invoker zeroes the output buffer using arg.M * arg.N as the byte count. However, arg.M is the padded sorted-token-id length from MOE routing, which can be much larger than the actual output allocation (NumTokens * TopK * N). This causes hipMemsetAsync to write beyond the buffer, and the silently-swallowed HIP error propagates to the subsequent kernel launch via hipGetLastError(). This patch replaces arg.M with arg.NumTokens * arg.TopK so the memset matches the actual output size. ## Technical Details <!-- Explain the changes along with any relevant GitHub links. --> ## Test Plan <!-- Explain any relevant testing done to verify this PR. --> ## Test Result <!-- Briefly summarize test outcomes. --> ## Submission Checklist - [x] Look over the contributing guidelines at https://github.com/ROCm/ROCm/blob/develop/CONTRIBUTING.md#pull-requests.
johannes-graner
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Mar 20, 2026
## Motivation Fix an out-of-bounds hipMemsetAsync in DeviceMoeGemmBlockScale that crashes split-K MOE GEMM with "HIP runtime error: invalid argument". When KBatch > 1, the invoker zeroes the output buffer using arg.M * arg.N as the byte count. However, arg.M is the padded sorted-token-id length from MOE routing, which can be much larger than the actual output allocation (NumTokens * TopK * N). This causes hipMemsetAsync to write beyond the buffer, and the silently-swallowed HIP error propagates to the subsequent kernel launch via hipGetLastError(). This patch replaces arg.M with arg.NumTokens * arg.TopK so the memset matches the actual output size. ## Technical Details <!-- Explain the changes along with any relevant GitHub links. --> ## Test Plan <!-- Explain any relevant testing done to verify this PR. --> ## Test Result <!-- Briefly summarize test outcomes. --> ## Submission Checklist - [x] Look over the contributing guidelines at https://github.com/ROCm/ROCm/blob/develop/CONTRIBUTING.md#pull-requests.
This was referenced Mar 31, 2026
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Motivation
Fix an out-of-bounds hipMemsetAsync in DeviceMoeGemmBlockScale that crashes split-K MOE GEMM with "HIP runtime error: invalid argument".
When KBatch > 1, the invoker zeroes the output buffer using arg.M * arg.N as the byte count. However, arg.M is the padded sorted-token-id length from MOE routing, which can be much larger than the actual output allocation (NumTokens * TopK * N). This causes hipMemsetAsync to write beyond the buffer, and the silently-swallowed HIP error propagates to the subsequent kernel launch via hipGetLastError().
This patch replaces arg.M with arg.NumTokens * arg.TopK so the memset matches the actual output size.
Technical Details
Test Plan
Test Result
Submission Checklist