Path A of the blocked 1.3.b investigation: fixes two architectural
issues atomically and wires the launcher.
(1) Bug fix: dd_state_kernel.cu was recomputing new_equity =
PS_PREV_EQUITY + pnl_step and writing it back, but experience_env_step
already maintains PS_PREV_EQUITY (experience_kernels.cu:3473-3475) —
wiring as-is would silently double-accumulate equity every step.
Kernel now READS PS_PREV_EQUITY / PS_PEAK_EQUITY only; does not
modify them. pnl_step parameter dropped from both kernel and
launcher signatures.
(2) Per-env shape decision: kernel is single-thread/single-block;
production has N envs but DD ISV slots [401..407) are scalars.
Picks 'env 0 as canonical observable' — kernel reads
pos_state[0 * PS_STRIDE + ...]. Per-env redesign (per-env tiles +
reduction kernel) deferred to Phase 1.3.b-followup if L40S smoke
shows single-env DD aggregation is insufficient.
(3) Wire-up: launch added at gpu_experience_collector.rs step 5b in
launch_timestep_loop, immediately after env_step writes PS_PREV_EQUITY,
outside the exp-fwd graph capture region (which ends at line ~3829,
well before env_step). Atomic per feedback_no_partial_refactor:
kernel signature change + oracle test update + launcher call site
update all in this commit.
Eliminates the Phase 1.3 orphan launcher per feedback_wire_everything_up.
Downstream Phase 3.3 / 3.5.2 / 3.5.4 / 3.5.5 readers will receive live
DD values when their consumer wiring lands.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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