fix(turbomind): restore INT8 KV quant-param offset in block layout - #4764
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After InternLM#4717 flattened per-layer layout to a byte offset, k_param() dropped the data-region base (old layer_param = layer_data + head_data(head_num)), so INT8 scale/zero writes overlapped K/V data and crashed (often surfacing later in MoE). quant_policy=0 was unaffected because params are unused.
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Pull request overview
This PR fixes the Turbomind attention KV-cache block memory layout so that INT8 (quantized) KV quantization parameters (scale/zero) are placed after the complete K/V data region for all heads, restoring the intended offset behavior.
Changes:
- Adjust
Layout::k_param()to add the base offset for the full K/V data region (head_data(head_num)) before indexing into per-head/per-token parameter storage. - Add an inline comment clarifying the intended layout and referencing the pre-#4717 behavior.
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lvhan028
approved these changes
Jul 20, 2026
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