gqa: ADR-0060/0062/0063/0064 unified GQA kernels + CPU cost model

Land the new GQA fused-attention kernels (ADR-0060) for prefill/decode
across long and short context, the TL discipline primitives they depend
on (ADR-0062 lazy load, ADR-0063 scratch_scope + copy_to), and the
per-op-type CPU issue cost model (ADR-0064). Remove the pre-ADR-0060
mesh-attention baseline now that the unified kernels supersede it.

ADR-0060 (long context)
- _gqa_decode.py: M-fold + 2-level chain reduce-to-root (Level-2
  intra-CUBE row-then-col + Level-1 inter-CUBE) — root-only output.
- _gqa_prefill.py: head-parallel + Ring KV rotation around C CUBEs,
  online-softmax merge per ring step, per-CUBE distributed output.
- Each merge stage wraps in scratch_scope() and persists running
  (m, l, O) via copy_to() to lift the 1 MiB scratch ceiling.

ADR-0060 §B.split.2 (short context, kv_per_cube in {1,2,4,8})
- _gqa_decode_short.py / _gqa_prefill_short.py: no cube-SP; each CUBE
  owns whole KV heads; PE-parallel heads with intra-group chain
  reduce. Prefill has no Ring KV (each head fully resident).

ADR-0062 (lazy tl.load): future-bearing TensorHandle, auto-wait at
first consuming op (dot/MATH/store/send/copy_to/composite).

ADR-0063 (tl.scratch_scope + tl.copy_to): scoped per-tile arena with
copy_to writeback primitive for persistent running state.

ADR-0064 (CPU issue cost model)
- common/cpu_issue_cost.py: per-op-type table (composite=40 ns,
  primitives=5 ns); ratios are load-bearing per D1.
- TLContext: issue_cost_table param; _emit_dispatch_overhead(kind)
  consults table with dispatch_cycles fallback (ADR-0046 §D6
  back-compat).
- Live PE_CPU paths (greenlet + legacy) construct TLContext with
  DEFAULT_CPU_ISSUE_COST so saturation lever (ADR-0060 §1) is
  measurable end-to-end.

P7 headline bench: milestone-gqa-headline writes per-panel
op_log_summary to 1H_milestone_output/gqa_headline/sweep.json. No
figure renderers yet (deferred).

Removals (pre-ADR-0060 baseline now superseded):
- benches: _attention_mesh_kv.py, _attention_mesh_mlo.py,
  _attention_mesh_mlo_2d.py, milestone_gqa_llama70b.py
- tests: test_attention_*, test_mesh_*, test_milestone_gqa_llama70b
- topology: llama70b_4sip.yaml (only consumer was the deleted diag)
- artifacts: 1H_milestone_output/gqa/ (sweep.json + 5 PNGs)
- tests/gqa/ plot helper + test (broken on Windows Tcl/Tkinter)
- ADR-0060/0061 references to deleted file paths cleaned up
  (EN + KO kept in sync).

Tests: 124/124 focused regression green (attention + Phase E + TL
discipline + triton_emu + pe_components). Full regression: 764 pass,
2 pre-existing test_bench_registry failures (stale EXPECTED_NAMES
across multiple benches, not introduced here).

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
This commit is contained in:
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"""Phase 1 spec test for P2a GQA decode SP (chain reduce-to-root, Level-2 only).
P2a is the first half of DDD-0060 P2: the kernel becomes multi-PE within
one CUBE and reduces to root (PE 0) using a chain over the 1D intra-cube
ring (W direction). This **replaces the baseline's bidirectional O(N)
fan-out** where every rank ends with O — ADR-0060 §A.2's headline.
Deviation from DDD-0060 §7 P2 gate: the gate text asks for
``⌈log₂ P⌉`` reduce rounds. The intra-cube SFR install
(``configure_sfr_intracube_pe_ring``) wires only a 1D E/W ring, so a
true tree would require either multi-hop forwarding or a new SFR install
(future ADR). P2a uses a **chain reduce-to-root**: ``P-1`` rounds along
W. The architectural property the ADR cares about
(root-only output vs every-rank-has-O) is preserved; the logarithmic
collective is deferred.
P2b (deferred) covers Level-1 inter-CUBE center-mesh reduce (C>1).
Phase 1 (this commit): tests only — production code lands in Phase 2.
"""
from __future__ import annotations
from pathlib import Path
from kernbench.benches._gqa_decode import gqa_decode_kernel # noqa: F401
from kernbench.ccl.install import load_ccl_config, resolve_algorithm_config
from kernbench.ccl.sfr_config import configure_sfr_intercube_multisip
from kernbench.policy.placement.dp import DPPolicy
from kernbench.runtime_api.bench_runner import run_bench
from kernbench.runtime_api.types import resolve_device
from kernbench.sim_engine.engine import GraphEngine
from kernbench.topology.builder import resolve_topology
TOPOLOGY_DEFAULT = Path(__file__).resolve().parents[2] / "topology.yaml"
T_Q = 1
D_HEAD = 64
DTYPE = "f16"
def _ccl_cfg():
return resolve_algorithm_config(
load_ccl_config(), name="lrab_hierarchical_allreduce",
)
def _engine_factory(t, d):
return GraphEngine(getattr(t, "topology_obj", t), enable_data=True)
def _run_decode_sp(*, h_q: int, h_kv: int, P: int, S_kv: int):
"""Single-CUBE SP decode: P PEs share the work along the intra-cube ring."""
topo = resolve_topology(str(TOPOLOGY_DEFAULT))
def _bench_fn(ctx):
configure_sfr_intercube_multisip(ctx.engine, ctx.spec, _ccl_cfg())
dp_full = DPPolicy(cube="replicate", pe="replicate",
num_cubes=1, num_pes=P)
dp_kv = DPPolicy(cube="replicate", pe="row_wise",
num_cubes=1, num_pes=P)
q = ctx.zeros((T_Q, h_q * D_HEAD),
dtype=DTYPE, dp=dp_full, name=f"q_h{h_q}_kv{h_kv}_p{P}")
# KV: total S_kv split across P PEs along axis 0 (row_wise sharding).
# Each PE sees (S_kv/P, h_kv·D_HEAD).
k = ctx.zeros((S_kv, h_kv * D_HEAD),
dtype=DTYPE, dp=dp_kv, name=f"k_h{h_q}_kv{h_kv}_p{P}")
v = ctx.zeros((S_kv, h_kv * D_HEAD),
dtype=DTYPE, dp=dp_kv, name=f"v_h{h_q}_kv{h_kv}_p{P}")
o = ctx.empty((T_Q, h_q * D_HEAD),
dtype=DTYPE, dp=dp_full, name=f"o_h{h_q}_kv{h_kv}_p{P}")
ctx.launch(
f"gqa_decode_sp_h{h_q}_kv{h_kv}_p{P}",
gqa_decode_kernel,
q, k, v, o,
T_Q, S_kv, h_q, h_kv, D_HEAD,
1, P, # C=1, P=P (single-CUBE SP)
_auto_dim_remap=False,
)
return run_bench(
topology=topo,
bench_fn=_bench_fn,
device=resolve_device(None),
engine_factory=_engine_factory,
)
def _count(op_log, name: str) -> int:
return sum(1 for r in op_log if r.op_name == name)
# ── Root-only write ────────────────────────────────────────────────────
def test_sp_chain_reduce_root_only_writes_o():
"""ADR-0060 §A.2: only the root rank (PE 0) writes O. Baseline today
has every rank write the full final O (bidirectional fan-out)."""
result = _run_decode_sp(h_q=1, h_kv=1, P=8, S_kv=64)
assert result.completion.ok, f"P=8 chain reduce failed: {result.completion}"
n_writes = _count(result.engine.op_log, "dma_write")
assert n_writes == 1, (
f"reduce-to-root must produce exactly 1 dma_write (PE 0); "
f"got {n_writes}"
)
# ── Chain step count ───────────────────────────────────────────────────
def test_sp_chain_reduce_p_minus_one_ipcq_pairs():
"""Chain reduce-to-root has P-1 send→recv pairs along the W chain;
each pair logs one ``ipcq_copy`` (inbound DMA, per
``milestone_gqa_llama70b._summarize_op_log``). Each chain step ships
the triplet (m, , O) → 3 handles per step → 7 steps × 3 = 21."""
result = _run_decode_sp(h_q=1, h_kv=1, P=8, S_kv=64)
assert result.completion.ok, f"P=8 chain reduce failed: {result.completion}"
n_copy = _count(result.engine.op_log, "ipcq_copy")
expected = (8 - 1) * 3
assert n_copy == expected, (
f"chain reduce: expected {expected} ipcq_copy (P-1=7 steps × "
f"3 handles m//O); got {n_copy}"
)
# ── Real GQA × SP combined ─────────────────────────────────────────────
def test_sp_real_gqa_h_q_eight_h_kv_one_p_eight():
"""The combined unlock: real GQA (h_q=G·h_kv with G=8) AND SP
(P=8) together — neither expressible by the baseline."""
result = _run_decode_sp(h_q=8, h_kv=1, P=8, S_kv=64)
assert result.completion.ok, (
f"real GQA + SP combined run failed: {result.completion}"
)
n_writes = _count(result.engine.op_log, "dma_write")
assert n_writes == 1, (
f"root-only write must hold under M-fold too; got {n_writes}"
)
# ── Degenerate P=1 ────────────────────────────────────────────────────
def test_sp_p_one_degenerate_no_ipcq_traffic():
"""P=1: SP degenerates to a single rank. No IPCQ traffic; one dma_write."""
result = _run_decode_sp(h_q=8, h_kv=1, P=1, S_kv=16)
assert result.completion.ok, f"P=1 degenerate failed: {result.completion}"
n_send = _count(result.engine.op_log, "ipcq_send")
n_recv = _count(result.engine.op_log, "ipcq_recv")
assert n_send == 0, f"P=1 must have no ipcq_send; got {n_send}"
assert n_recv == 0, f"P=1 must have no ipcq_recv; got {n_recv}"
n_writes = _count(result.engine.op_log, "dma_write")
assert n_writes == 1, f"P=1: one dma_write; got {n_writes}"