Adds 4 new kernel symbols alongside the existing single-sample ones —
zero changes to current call sites, so the in-flight qf5mj baseline is
unaffected. The next commit wires these into PerceptionTrainer's K
loop and exposes --batch-size in the CLI.
cfc_step_batched processes [n_batch, n_in/n_hid] tensors
cfc_step_backward_batched same; shared mem holds sd_pre[B, n_hid]
+ sdecay[n_hid] (~16 KiB at B=32, well
under L40S 48 KiB block limit). Param
grads (grad_b/grad_w_in/grad_w_rec/
grad_tau) accumulated via += — thread i
is sole writer to its row across all
samples, so no atomicAdd and no per-
batch scratch buffer.
multi_horizon_heads_batched [n_batch, 5] sigmoid outputs from
[n_batch, 128] hidden inputs.
multi_horizon_heads_backward_batched
shared mem holds sd_z[B, 5]. grad_w
/ grad_b += across batch (thread tid
sole writer). grad_h carries the
optional per-sample grad_h_carry
(cfc recurrence chain).
Design notes:
- Threading: one block of n_hid threads. Each thread loops over
b ∈ 0..B internally. This avoids cross-block races on grad_*
buffers and keeps the existing "no atomicAdd" discipline. Cost:
less raw parallelism than grid-batching, but the bottleneck is
Mamba2 (already batch-parallel via its own kernel grid).
- Per-thread accumulators: grad_b / grad_tau land in registers,
flushed once at end. grad_w_in / grad_w_rec written += per-b
(thread sole writer to its row, safe).
- All B samples processed in stream order inside one kernel launch
— saves K * (B-1) launches per sequence vs serialising B
independent calls.
77 ml-alpha tests pass (kernels not yet exercised — wiring is the
next commit).
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
829ddfa62c