Plan 4 Task 5 Mode A. Light, ISV-only, no model parameters added,
no checkpoint break.
ISV tail-append:
- [87] VSN_MAG_EMA_INDEX
- [88] VSN_DIR_EMA_INDEX
- [89] MAMBA2_RETENTION_EMA_INDEX
- Fingerprint shifted [85,86] → [90,91]; ISV_TOTAL_DIM 87 → 92
Producer (attention_focus_ema_kernel.cu):
- Single kernel, 3-block multi-reduction, fully GPU-driven
- Block 0 reduces magnitude-branch VSN-weight slice of params buffer
- Block 1 reduces direction-branch VSN-weight slice
- Block 2 reduces mamba2_h_enriched buffer
- Each block: 256-thread smem tree-reduce → mean |x| → EMA-update
ISV slot via pinned device-mapped (no explicit DtoH)
- Adaptive α matches Plan 3 Task 3 convention
GPU-only correction (per user direction "no dtoh, pinned memory"):
First-pass agent implementation used host-DtoH + CPU loop for the
Mamba2 retention scalar (mirroring the pre-existing
per_branch_vsn_mean() pattern). User flagged this as a violation
of spec §4.C.6 GPU-drives-CPU-reads even on cold path. Rewrote
the kernel to do all 3 reductions on-device via smem block-reduce,
reading params/mamba2 buffers via raw_ptr() and writing to pinned
ISV slots directly. Removed mamba2_retention_mean() from
GpuDqnTrainer + FusedTrainingCtx (was the host-DtoH culprit).
Read-only AttentionMonitor mirrors PlanThresholdMonitor pattern.
StateResetRegistry: all 3 slots FoldReset.
Smoke fold-2 best Sharpe 95.09, avg best_val_metric 10.98 — within
Plan 3 baseline range. ISV slots populate non-zero from epoch 2.
Pearl: cold-path is not an exception to GPU-drives-CPU-reads. If
the producer is computing a value (not just reading a CPU-side
constant), the compute belongs on GPU regardless of frequency.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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