Gahow Wang 65a2264227 docs: Phase T14 — fused flash-attention design ...

Design doc for the hand-written single fused flash-attention kernel:
online softmax tiled over KV, NEVER materializing the [bh,S,S] score
matrix; flash-style backward (recompute scores from saved logsumexp +
D=ΣdO·O, dQ/dK/dV). Opt-in --flash; composed T10 path stays default.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

2026-06-17 23:10:16 +08:00

..

runs

docs: run v8 — dim1024 capacity helps (val 2.98)

2026-06-17 15:12:01 +08:00

00-build-chain.md

docs: backfill T1 build-chain

2026-06-15 15:12:55 +08:00

01-tensor.md

docs: Phase T2 — tensor abstraction

2026-06-15 15:12:55 +08:00

02-gemm-autodiff.md

docs: Phase T3 — GEMM fwd/bwd + finite-diff

2026-06-15 15:27:03 +08:00

03-autograd-engine.md

docs: Phase T4 — autograd engine

2026-06-15 15:53:55 +08:00

04-tiny-transformer.md

docs: Phase T5 — tiny transformer

2026-06-15 16:09:30 +08:00

05-training-loop.md

docs: Phase T6 — training loop

2026-06-15 16:30:14 +08:00

06-performance.md

docs: Phase T7 — performance

2026-06-15 17:00:29 +08:00

07-distributed.md

docs: Phase T8 — distributed data parallel

2026-06-15 17:15:49 +08:00

08-export-xserv.md

docs: T9 verification results (xserv == xtrain, dash5)

2026-06-15 17:37:46 +08:00

09-batched-forward.md

docs: Phase T10 — batched forward

2026-06-16 00:44:50 +08:00

10-caching-allocator.md

perf: KI-5 FIXED — single-GPU 40K->93K tok/s, DDP scaling 1.3x->5x@8

2026-06-16 11:15:02 +08:00

11-bf16-mixed-precision.md

perf: KI-2 FIXED — dim768 bf16 fits batch 32, tok/s 31.5K→40.8K

2026-06-16 14:28:20 +08:00

12-activation-recompute.md

perf: KI-3 fixed — dim1024 batch32 fits, mem 31.1→14.6GB, tok/s 39.7K→31.5K

2026-06-17 09:50:29 +08:00

13-flash-attention.md

docs: Phase T14 — fused flash-attention design

2026-06-17 23:10:16 +08:00

evolution.md

docs: run v8 — dim1024 capacity helps (val 2.98)

2026-06-17 15:12:01 +08:00

known-issues.md

perf: KI-3 fixed — dim1024 batch32 fits, mem 31.1→14.6GB, tok/s 39.7K→31.5K

2026-06-17 09:50:29 +08:00