Each batch element is an independent backtest session with its own
$35k starting capital. The CMDP kernel had been summing per-batch
rewards into a single ISV slot — at b=1024 the accumulator grew
b_size× faster than the -$3500 single-account DD limit, tripping
session_dd_triggered globally in ~250 steps (cluster alpha-rl-2j9k9
step 320: session_pnl_usd=-$5775, all 1024 sessions locked out).
Same flaw on consec_loss_count: any 10 losses across the batch in a
single step triggered cooldown for the entire fleet.
Refactor — every Layer-1 state shard is per-batch:
session_pnl_per_batch_d [b_size] f32
session_dd_triggered_per_batch_d [b_size] f32
consec_loss_per_batch_d [b_size] f32
cooldown_remaining_per_batch_d [b_size] f32
`actions_to_market_targets` now reads per-batch DD-triggered + cooldown,
so one account hitting its limit does not lock out the other 1023.
Summary ISV slots (RL_SESSION_PNL_USD, RL_CONSEC_LOSS_COUNT,
RL_SESSION_DD_TRIGGERED, RL_COOLDOWN_REMAINING_STEPS) are now
kernel-OUT only — they expose worst-account / any-triggered / max
aggregates for diag + the single IQN-τ consumer ("be pessimistic
when ANY session is in trouble").
3 raw `actions_to_market_targets_fn.cu_function()` launch sites in
integrated.rs were updated atomically per `feedback_no_partial_refactor`
— public wrapper + 2 internal step_with_lobsim sites. The first
attempt hit CUDA_ERROR_INVALID_VALUE in integrated_trainer_smoke
because only the public wrapper had been updated.
Validation:
- 12/12 risk_stack_invariants pass on per-batch semantics (G1-G4
rewritten to seed per-batch buffers via write_slice_f32_d_pub).
- 20/20 trade_management_kernels still pass (actions gating intact).
- integrated_trainer_smoke passes end-to-end.
- Local b=128 1k smoke: 1000/1000 steps clean, no NaN. CMDP behavior
matches design: worst-of-128 hit DD (-$34k > $3500 limit), other 127
unaffected. IQN τ floored at 0.1 (worst-account drawdown >>10%),
Kelly = 0.0 (observed edge negative: wr=0.21, R=1.57).
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