./kernelbenchhardv3runsclaude · claude-opus-4-7
claude / claude-opus-4-7 session: 400239da-f68f-4aa1-8a16-bfbfbe931013 cwd: /home/infatoshi/cuda/KernelBench-Hard
INCOMPLETE SESSION. harness exited with code 143. The transcript below is usable but may be missing the agent's final tool calls or summary. Don't score this run as a clean failure or success.
harness
claude
model
claude-opus-4-7
turns
76
tools called
50
events
141
input toks
106
output toks
3,620
cache hit
7,305,478
solution.py
final answer
benchmark.log
check.log
result.json
"""Custom KDA forward (chunk form) using Triton kernels for SM120.

Implementation notes:
  - g is rescaled by RCP_LN2 so we can use exp2 throughout (faster than exp).
  - In-chunk cumsum on g is fused into the intra kernel via tl.cumsum.
  - Phase 1 (intra): per-chunk forward substitution on the (I + L) factor and
    materialize the chunk-local Akk_inv, w, u tensors.
  - Phase 2 (inter): sequential per-(b, h) loop over chunks computing the state
    h and the output o, with the V dim split into BV-tiles for parallelism.
"""
from __future__ import annotations

import torch
import torch.nn as nn
import triton
import triton.language as tl

RCP_LN2 = 1.4426950408889634  # log2(e), so exp(x) = exp2(x * RCP_LN2)


@triton.jit
def _kda_intra_kernel(
    k_ptr,
    v_ptr,
    g_in_ptr,
    g_out_ptr,
    beta_ptr,
    A_ptr,
    w_ptr,
    u_ptr,
    T,
    H: tl.constexpr,
    K: tl.constexpr,
    V: tl.constexpr,
    BT: tl.constexpr,
    SCALE_LOG: tl.constexpr,
):
    """Per-chunk preparation: cumsum g; build Akk_inv*beta_col; w, u.

    Grid: (B*H, NT)
    """
    i_bh = tl.program_id(0)
    i_n = tl.program_id(1)
    i_b = i_bh // H
    i_h = i_bh % H
    NT = T // BT

    offs_t = tl.arange(0, BT)
    offs_k = tl.arange(0, K)
    offs_v = tl.arange(0, V)

    # ---------- Pointers ----------
    # k, g: (B, T, H, K) — strides (T*H*K, H*K, K, 1)
    k_base = i_b * T * H * K + i_n * BT * H * K + i_h * K
    g_base = k_base
    # v: (B, T, H, V)
    v_base = i_b * T * H * V + i_n * BT * H * V + i_h * V
    # beta: (B, T, H)
    beta_base = i_b * T * H + i_n * BT * H + i_h
    # A: (B, NT, H, BT, BT) contiguous on the last two dims
    A_base = i_b * NT * H * BT * BT + i_n * H * BT * BT + i_h * BT * BT

    # ---------- Load k, g, beta ----------
    kg_ptrs_t = offs_t[:, None] * H * K + offs_k[None, :]
    b_k = tl.load(k_ptr + k_base + kg_ptrs_t)            # (BT, K) bf16
    b_g_raw = tl.load(g_in_ptr + g_base + kg_ptrs_t).to(tl.float32) * SCALE_LOG
    b_g = tl.cumsum(b_g_raw, axis=0)                      # (BT, K) fp32

    # Save the cumsumed g back to global (used by inter kernel).
    tl.store(g_out_ptr + g_base + kg_ptrs_t, b_g)

    b_beta = tl.load(beta_ptr + beta_base + offs_t * H).to(tl.float32)  # (BT,)

    # ---------- Akk_raw = -beta_row * (k*exp(g)) @ (k*exp(-g)).T ----------
    b_eg = tl.exp2(b_g)             # (BT, K) fp32
    b_eng = tl.exp2(-b_g)           # (BT, K) fp32
    b_kf = b_k.to(tl.float32) * b_eg
    b_kg = b_k.to(tl.float32) * b_eng
    b_A = tl.dot(b_kf.to(b_k.dtype), tl.trans(b_kg).to(b_k.dtype))  # (BT, BT) fp32
    mask_strict_lower = offs_t[:, None] > offs_t[None, :]
    b_A = tl.where(mask_strict_lower, -b_A * b_beta[:, None], 0.0)

    # ---------- Forward substitute (BT iterations) ----------
    # for i in 1..BT-1: A[i, :i] += sum_m A[i, m] * A[m, :i]   for m < i
    for i in tl.static_range(1, BT):
        is_row = (offs_t == i)
        # row i of A (BT,)
        row_i = tl.sum(tl.where(is_row[:, None], b_A, 0.0), axis=0)
        # (row_i @ A)[j] = sum_m row_i[m] * A[m, j]
        update = tl.sum(row_i[:, None] * b_A, axis=0)
        # write only the lower part of row i
        write_mask = is_row[:, None] & (offs_t[None, :] < i)
        b_A = tl.where(write_mask, b_A + update[None, :], b_A)

    # Add identity on the diagonal
    b_A = tl.where(offs_t[:, None] == offs_t[None, :], b_A + 1.0, b_A)
    # Multiply by beta_col: A *= beta[None, :]
    b_A = b_A * b_beta[None, :]

    # ---------- Store A_inv (fp32 for downstream precision) ----------
    A_ptrs = offs_t[:, None] * BT + offs_t[None, :]
    tl.store(A_ptr + A_base + A_ptrs, b_A)

    # ---------- w = A @ (g.exp() * k) ----------
    b_w = tl.dot(b_A.to(b_k.dtype), b_kf.to(b_k.dtype))   # (BT, K) fp32
    tl.store(w_ptr + k_base + kg_ptrs_t, b_w.to(b_k.dtype))

    # ---------- u = A @ v ----------
    v_ptrs_t = offs_t[:, None] * H * V + offs_v[None, :]
    b_v = tl.load(v_ptr + v_base + v_ptrs_t)              # (BT, V) bf16
    b_u = tl.dot(b_A.to(b_v.dtype), b_v)                  # (BT, V) fp32
    tl.store(u_ptr + v_base + v_ptrs_t, b_u.to(b_v.dtype))


@triton.jit
def _kda_inter_kernel(
    q_ptr,
    k_ptr,
    g_ptr,
    w_ptr,
    u_ptr,
    o_ptr,
    scale,
    T,
    H: tl.constexpr,
    K: tl.constexpr,
    V: tl.constexpr,
    BT: tl.constexpr,
    BV: tl.constexpr,
    SCALE_LOG: tl.constexpr,
):
    """Inter-chunk recurrence: maintain state S, compute o.

    Grid: (B*H, V/BV)
    Each program handles one (b, h) pair and one V-slice. Sequential over chunks.
    """
    i_bh = tl.program_id(0)
    i_v = tl.program_id(1)
    i_b = i_bh // H
    i_h = i_bh % H
    NT = T // BT

    offs_t = tl.arange(0, BT)
    offs_k = tl.arange(0, K)
    offs_v = tl.arange(0, BV)

    v_lo = i_v * BV

    # Strict-upper mask for Aqk (zero out strict-upper, keep diag and below)
    mask_su = offs_t[:, None] < offs_t[None, :]

    # State S: (K, BV) fp32
    b_S = tl.zeros((K, BV), dtype=tl.float32)

    for i_n in range(NT):
        # Pointers
        k_base = i_b * T * H * K + i_n * BT * H * K + i_h * K
        v_base = i_b * T * H * V + i_n * BT * H * V + i_h * V + v_lo

        kg_ptrs_t = offs_t[:, None] * H * K + offs_k[None, :]
        v_ptrs_t = offs_t[:, None] * H * V + offs_v[None, :]

        # Load q, k, g, w, u_slice
        b_q = tl.load(q_ptr + k_base + kg_ptrs_t)              # (BT, K) bf16
        b_k = tl.load(k_ptr + k_base + kg_ptrs_t)              # (BT, K) bf16
        b_g = tl.load(g_ptr + k_base + kg_ptrs_t)              # (BT, K) fp32
        b_w = tl.load(w_ptr + k_base + kg_ptrs_t)              # (BT, K) bf16
        b_u = tl.load(u_ptr + v_base + v_ptrs_t)               # (BT, BV) bf16

        # Aqk[c, c'] = q[c] * exp(g[c] - g[c']) * k[c']
        # = (q * exp(g))[c] @ (k * exp(-g))[c'].T
        b_eg = tl.exp2(b_g)
        b_eng = tl.exp2(-b_g)
        # apply scale to q here so q @ S also gets scaled
        b_qe = (b_q.to(tl.float32) * b_eg * scale).to(b_q.dtype)
        b_kf = (b_k.to(tl.float32) * b_eng).to(b_k.dtype)
        b_Aqk = tl.dot(b_qe, tl.trans(b_kf))                   # (BT, BT) fp32
        b_Aqk = tl.where(mask_su, 0.0, b_Aqk)

        # v_new = u - w @ S        (BT, BV)
        b_v_new = b_u.to(tl.float32) - tl.dot(b_w, b_S.to(b_w.dtype))

        # o = (q*exp(g)*scale) @ S + Aqk @ v_new
        b_o = tl.dot(b_qe, b_S.to(b_qe.dtype))
        b_o += tl.dot(b_Aqk.to(b_w.dtype), b_v_new.to(b_w.dtype))

        # Store o
        tl.store(o_ptr + v_base + v_ptrs_t, b_o.to(b_q.dtype))

        # Update S: S = exp(g_last) * S + (k * exp(g_last - g)).T @ v_new
        # g_last = g[BT-1, :]
        g_last_off = (BT - 1) * H * K
        b_g_last = tl.load(g_ptr + k_base + g_last_off + offs_k)  # (K,) fp32
        b_S = b_S * tl.exp2(b_g_last)[:, None]
        b_state_term = (b_k.to(tl.float32) * tl.exp2(b_g_last[None, :] - b_g)).to(b_k.dtype)
        b_S = b_S + tl.dot(tl.trans(b_state_term), b_v_new.to(b_state_term.dtype))


def kda_forward(
    q: torch.Tensor,
    k: torch.Tensor,
    v: torch.Tensor,
    g: torch.Tensor,
    beta: torch.Tensor,
    scale: float,
    chunk_size: int = 64,
) -> torch.Tensor:
    """KDA forward (chunk form). Returns o of shape (B, T, H, V) with v's dtype."""
    B, T, H, K = q.shape
    V = v.shape[-1]
    BT = chunk_size
    assert T % BT == 0
    NT = T // BT
    assert q.is_contiguous() and k.is_contiguous() and v.is_contiguous() and beta.is_contiguous()

    # Workspaces
    g_cum = torch.empty_like(g)                                       # fp32, (B, T, H, K)
    A_inv = torch.empty(B, NT, H, BT, BT, device=q.device, dtype=torch.float32)
    w = torch.empty_like(k)                                           # bf16, (B, T, H, K)
    u = torch.empty_like(v)                                           # bf16, (B, T, H, V)
    o = torch.empty_like(v)                                           # bf16, (B, T, H, V)

    # Phase 1: intra-chunk preparation
    grid_intra = (B * H, NT)
    _kda_intra_kernel[grid_intra](
        k, v, g, g_cum, beta, A_inv, w, u,
        T,
        H=H, K=K, V=V, BT=BT,
        SCALE_LOG=RCP_LN2,
        num_warps=4,
        num_stages=2,
    )

    # Phase 2: inter-chunk recurrence
    BV = 32  # split V into BV-sized tiles
    assert V % BV == 0
    grid_inter = (B * H, V // BV)
    _kda_inter_kernel[grid_inter](
        q, k, g_cum, w, u, o, scale,
        T,
        H=H, K=K, V=V, BT=BT, BV=BV,
        SCALE_LOG=RCP_LN2,
        num_warps=4,
        num_stages=2,
    )
    return o


class Model(nn.Module):
    """KDA forward (chunk form). Mirror of reference.Model — no learned params."""

    def __init__(self, B: int, T: int, H: int, K: int, V: int, chunk_size: int = 64):
        super().__init__()
        self.B, self.T, self.H, self.K, self.V = B, T, H, K, V
        self.chunk_size = chunk_size
        self.scale = float(K) ** -0.5
        self.register_buffer("_dummy", torch.zeros(1), persistent=False)

    def forward(
        self,
        q: torch.Tensor,
        k: torch.Tensor,
        v: torch.Tensor,
        g: torch.Tensor,
        beta: torch.Tensor,
    ) -> torch.Tensor:
        return kda_forward(q, k, v, g, beta, scale=self.scale, chunk_size=self.chunk_size)


# Module-level shape shims (overridden by check.py / benchmark.py per shape).
B = 2
T = 1024
H = 8
K = 128
V = 128
CHUNK_SIZE = 64


def get_inputs():
    torch.manual_seed(0)
    q = torch.randn(B, T, H, K, dtype=torch.bfloat16) * 0.1
    k = torch.randn(B, T, H, K, dtype=torch.bfloat16) * 0.1
    v = torch.randn(B, T, H, V, dtype=torch.bfloat16) * 0.1
    g = (torch.randn(B, T, H, K, dtype=torch.float32) * 0.1 - 0.05)
    beta = torch.sigmoid(torch.randn(B, T, H, dtype=torch.bfloat16))
    return [q, k, v, g, beta]


def get_init_inputs():
    return [B, T, H, K, V, CHUNK_SIZE]
Let me check the current monitor and then try some optimizations. First let me precompute Aqk and see the impact.
/home/infatoshi/cuda/KernelBench-Hard/.venv/lib/python3.11/site-packages/torch/_inductor/compile_fx.py:322: UserWarning: TensorFloat32 tensor cores for float32 matrix multiplication available but not enabled. Consider setting `torch.set_float32_matmul_precision('high')` for better performance.
  warnings.warn(
PASS
{
    "problem": "02_kda_cutlass",
    "harness": "claude",
    "model": "claude-opus-4-7",
    "reasoning_effort": "max",
    "has_solution": true,
    "correct": true,
    "peak_fraction": null,
    "elapsed_seconds": 887,
    "harness_exit_code": 143,
    "session_complete": false,
    "usage": {"input_tokens": 106, "output_tokens": 3620, "cache_read_tokens": 7305478, "cache_creation_tokens": 336586, "reasoning_tokens": null, "total_cost_usd": null}
}

timeline (141 events)

system — init
session start cwd=/home/infatoshi/cuda/KernelBench-Hard model=claude-opus-4-7 permissions=bypassPermissions
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in 6out 8cache_r 16230cache_w 19056
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Bash
args
{
  "command": "pwd && ls -la",
  "description": "Check current directory and contents"
}
in 6out 8cache_r 16230cache_w 19056
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stdout (1710 chars) — TRUNCATED
/home/infatoshi/cuda/KernelBench-Hard
drwxrwxr-x infatoshi infatoshi  4.0 KB Mon Apr 27 21:56:40 2026 .
drwxr-xr-x infatoshi infatoshi  4.0 KB Tue Apr 28 00:55:24 2026 ..
.rw-rw-r-- infatoshi infatoshi  1.6 KB Fri Apr 24 00:32:28 2026 .cursorrules
drwxrwxr-x infatoshi infatoshi  4.0 KB Tue Apr 28 02:09:38 2026 .git
.rw-rw-r-- infatoshi infatoshi  262 B  Fri Apr 24 00:30:12 2026 .gitignore
drwxrwxr-x infatoshi infatoshi  4.0 KB Fri Apr 24 00:41:00 2026 .pytest_cache
.rw-rw-r-- infatoshi infatoshi    5 B  Fri Apr 24 00:30:15 2026 .python-version
drwxrwxr-x infatoshi infatoshi  4.0 KB Fri Apr 24 00:40:58 2026 .ruff_cache
drwxrwxr-x infatoshi infatoshi  4.0 KB Fri Apr 24 00:40:54 2026 .venv
.rw-rw-r-- infatoshi infatoshi 1012 B  Mon Apr 27 02:25:28 2026 AGENTS.md
.rw-rw-r-- infatoshi infatoshi  6.9 KB Mon Apr 27 02:24:34 2026 CLAUDE.md
.rw-rw-r-- infatoshi infatoshi   45 KB Mon Apr 27 21:56:40 2026 DEVLOG.md
drwxrwxr-x infatoshi infatoshi  4.0 KB Fri Apr 24 00:30:02 2026 docs
.rw-rw-r-- infatoshi infatoshi  1.0 KB Mon Apr 27 04:26:18 2026 LICENSE
drwxrwxr-x infatoshi infatoshi  4.0 KB Fri Apr 24 00:30:02 2026 outputs
drwxrwxr-x infatoshi infatoshi  4.0 KB Fri Apr 24 00:30:02 2026 problems
.rw-rw-r-- infatoshi infatoshi  663 B  Sat Apr 25 22:54:16 2026 pyproject.toml
.rw-rw-r-- infatoshi infatoshi  8.0 KB Sun Apr 26 00:07:33 2026 README.md
drwxrwxr-x infatoshi infatoshi  4.0 KB Tue Apr 28 04:05:34 2026 scripts
.rw-rw-r-- infatoshi infatoshi  6.5 KB Mon Apr 27 02:25:12 2026 SPEC.md

... (210 more chars)
assistant
Bash
args
{
  "command": "ls problems/",
  "description": "List problems"
}
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stdout (136 chars)
01_fp8_gemm
02_kda_cutlass
03_paged_attention
04_kahan_softmax
05_topk_bitonic
06_sonic_moe_swiglu
07_w4a16_gemm
08_metal_lightning_attn
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Bash
args
{
  "command": "ls problems/02_kda_cutlass/",
  "description": "List KDA problem files"
}
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tool
stdout (76 chars)
benchmark.py
check.py
problem.yaml
PROMPT.txt
reference.py
shapes.py
sota.py
assistant
Read /home/infatoshi/cuda/KernelBench-Hard/problems/02_kda_cutlass/reference.py
args
{
  "file_path": "/home/infatoshi/cuda/KernelBench-Hard/problems/02_kda_cutlass/reference.py"
}
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stdout (5561 chars) — TRUNCATED
1	"""Naive PyTorch reference for Kimi Delta Attention (KDA) forward, chunk form.
2	
3	This is the correctness oracle, NOT the SOTA baseline. It mirrors the
4	chunk-parallel formulation in fla/ops/kda/naive.py (Songlin Yang et al.)
5	without any Triton or CUDA optimization.
6	
7	Inputs (per the FLA convention):
8	  q, k : (B, T, H, K)   bf16   -- queries / keys
9	  v    : (B, T, H, V)   bf16   -- values
10	  g    : (B, T, H, K)   fp32   -- per-channel log-decay (in-chunk cumsum applied)
11	  beta : (B, T, H)      bf16   -- write strength
12	
13	Output:
14	  o    : (B, T, H, V)   bf16
15	
16	The agent must reproduce this output (within bf16 tolerance) using a CUTLASS
17	CuTe kernel on SM120 -- NOT by calling fla.ops.chunk_kda directly.
18	"""
19	from __future__ import annotations
20	
21	import torch
22	import torch.nn as nn
23	from einops import rearrange
24	
25	OP_TYPE = "linear_attention"
26	SUPPORTED_PRECISIONS = ["bf16"]
27	HARDWARE_REQUIRED = ["RTX_PRO_6000", "H100", "B200"]
28	
29	
30	def _naive_chunk_kda(
31	    q: torch.Tensor,
32	    k: torch.Tensor,
33	    v: torch.Tensor,
34	    g: torch.Tensor,
35	    beta: torch.Tensor,
36	    scale: float,
37	    chunk_size: int = 64,
38	) -> torch.Tensor:
39	    """KDA forward, no initial state, no final state. Returns o with v's dtype."""
40	    dtype = v.dtype
41	    B, T, H, K = q.shape
42	    V = v.shape[-1]
43	    BT = chunk_size
44	    assert T % BT == 0, f"T={T} must be a multiple of chunk_size={BT}"
45	    NT = T // BT
46

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Read /home/infatoshi/cuda/KernelBench-Hard/problems/02_kda_cutlass/PROMPT.txt
args
{
  "file_path": "/home/infatoshi/cuda/KernelBench-Hard/problems/02_kda_cutlass/PROMPT.txt"
}
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1	I need you to implement Kimi Delta Attention forward (chunk form) for the RTX PRO 6000 (SM120 Blackwell, GDDR7, 1.8 TB/s). The reference implementation is in reference.py and your kernel goes in solution.py. You can make whatever mess you want in this directory — scratch files, intermediate kernels, build artifacts, profiling traces — but the final answer has to be in solution.py with the same Model, get_inputs, and get_init_inputs interface as reference.py.
2	
3	The op is the chunk-parallel KDA forward from the FLA library: q and k of shape (B, T, H, K) in bf16, v of shape (B, T, H, V) in bf16, g of shape (B, T, H, K) in fp32 (per-channel log-decay with in-chunk cumsum already applied), beta of shape (B, T, H) in bf16, scale a python float, chunk_size 64, no initial state, no final state. You return o of shape (B, T, H, V) in bf16. Correctness tolerance is 0.05 abs/rel — the long recurrence accumulates more error than a single GEMM so the bar's a bit looser than default bf16. The shapes you have to handle are B=2 T=1024 H=8 K=128 V=128 (short-context training step), B=2 T=2048 H=8 K=128 V=128 (the headline shape from the Kimi Linear paper), B=1 T=4096 H=8 K=128 V=128 (long context that stresses the inter-chunk recurrence), and B=1 T=2048 H=4 K=128 V=128 (thin batch decode).
4	
5	This needs to be a real custom kernel — the whole point of the problem is to write the chunk-parallel attention yourself, not call FLA's existing implementation. Don't import or call fla.ops.kda, f

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Read /home/infatoshi/cuda/KernelBench-Hard/problems/02_kda_cutlass/check.py
args
{
  "file_path": "/home/infatoshi/cuda/KernelBench-Hard/problems/02_kda_cutlass/check.py"
}
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1	"""Correctness runner for KDA forward (chunk form).
2	
3	Runs solution.Model vs reference.Model across all shapes in shapes.py, 3 seeds
4	each, with per-dtype atol/rtol (bf16 default 1e-2 plus a 5e-2 override for
5	this problem). Also rejects forbidden ops by grep.
6	"""
7	import re
8	import sys
9	from pathlib import Path
10	
11	import torch
12	import yaml
13	
14	# Make the repo's src/ importable
15	REPO_ROOT = Path(__file__).resolve().parents[2]
16	sys.path.insert(0, str(REPO_ROOT))
17	
18	from src.eval.correctness import check_correctness  # noqa: E402
19	
20	
21	def _apply_shape(reference, shape):
22	    """Override reference's module-level shape shims so get_inputs/get_init_inputs match."""
23	    for k, v in shape.items():
24	        setattr(reference, k, v)
25	
26	
27	def main():
28	    try:
29	        import reference
30	        import shapes
31	        import solution
32	    except Exception as e:
33	        print(f"FAIL: import error: {e}")
34	        sys.exit(1)
35	
36	    problem_yaml = Path("problem.yaml")
37	    meta = yaml.safe_load(problem_yaml.read_text()) if problem_yaml.exists() else {}
38	
39	    # --- Forbidden-op check ------------------------------------------------
40	    sol_src = Path("solution.py").read_text() if Path("solution.py").exists() else ""
41	    for forbidden in meta.get("forbidden", []):
42	        pat = re.escape(forbidden)
43	        if re.search(pat, sol_src):
44	            print(f"FAIL: forbidden op used: {forbidden}")
45	         

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Read /home/infatoshi/cuda/KernelBench-Hard/problems/02_kda_cutlass/benchmark.py
args
{
  "file_path": "/home/infatoshi/cuda/KernelBench-Hard/problems/02_kda_cutlass/benchmark.py"
}
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1	"""Roofline benchmark for KDA forward (chunk form).
2	
3	For each shape: times eager reference, compiled reference, SOTA (FLA's Triton
4	chunk_kda, if available on this GPU), and the agent's solution. Reports
5	achieved TFLOPS, GB/s, and peak_fraction.
6	
7	Output lines the harness picks up:
8	  shape=<idx> variant=<name> tflops=<N> gbps=<N> ms=<N>
9	  peak_fraction: <N>  (geomean over shapes of solution's peak_fraction)
10	"""
11	import sys
12	from math import exp, log
13	from pathlib import Path
14	
15	import torch
16	import yaml
17	
18	REPO_ROOT = Path(__file__).resolve().parents[2]
19	sys.path.insert(0, str(REPO_ROOT))
20	
21	from src.eval.roofline import compute_gbps, compute_tflops, peak_fraction  # noqa: E402
22	from src.eval.timing import time_fn  # noqa: E402
23	from src.hardware import get as get_hw  # noqa: E402
24	
25	
26	def _eval_formula(expr: str, vars: dict) -> float:
27	    return float(eval(expr, {"__builtins__": {}}, vars))
28	
29	
30	def _apply_shape(reference, shape):
31	    for k, v in shape.items():
32	        setattr(reference, k, v)
33	
34	
35	def main():
36	    import reference
37	    import shapes
38	    import solution
39	
40	    meta = yaml.safe_load(Path("problem.yaml").read_text())
41	    hw = get_hw(meta["hardware"][0])
42	    peak_tflops = hw.peak_tflops_dense.get(meta["peak_tflops_key"], 0.0)
43	    peak_gbps = hw.peak_bandwidth_gb_s
44	    regime = meta.get("regime", "compute")
45	    flops_formula = meta["flops_formula"]
46	    bytes_form

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Read /home/infatoshi/cuda/KernelBench-Hard/problems/02_kda_cutlass/problem.yaml
args
{
  "file_path": "/home/infatoshi/cuda/KernelBench-Hard/problems/02_kda_cutlass/problem.yaml"
}
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1	name: 02_kda_cutlass
2	display_name: "Kimi Delta Attention (chunk forward) via CUTLASS CuTe"
3	precision: bf16
4	regime: compute
5	
6	# Approximate FLOPs per forward call. KDA forward (chunk form) breakdown per
7	# token across all heads:
8	#   - intra-chunk Aqk (q @ k.T with decay): 2*BT*K
9	#   - intra-chunk Akk + cumulative invert : ~3*BT*K + BT^2
10	#   - w = A @ (g.exp()*k):                  2*BT*K
11	#   - u = A @ v:                            2*BT*V
12	#   - inter-chunk q @ S:                    2*K*V
13	#   - inter-chunk (Aqk @ v_i):              2*BT*V
14	#   - state update S += k.T @ v_i:          2*K*V
15	# Aggregating with a constant of 4 (typical for chunked linear attention) gives
16	# the formula below. Used only for roofline reporting -- not graded directly.
17	flops_formula: "4 * B * T * H * (K*V + CHUNK_SIZE*K + CHUNK_SIZE*V)"
18	
19	# Bytes moved (lower bound): one read of q,k,v,g,beta and one write of o.
20	bytes_formula: "B*T*H*K*2 + B*T*H*K*2 + B*T*H*V*2 + B*T*H*K*4 + B*T*H*2 + B*T*H*V*2"
21	
22	hardware: [RTX_PRO_6000]
23	peak_tflops_key: bf16  # KDA's heavy work is bf16 @ bf16 -> fp32 GEMM-equivalent
24	peak_bandwidth_key: dram
25	
26	# bf16 default tolerance from src/eval/correctness.py is 1e-2 atol/rtol; KDA's
27	# long recurrence accumulates more error than a single GEMM, so we relax slightly.
28	tolerance:
29	  torch.bfloat16: 0.05  # was "5e-2" -- PyYAML parses un-dotted sci-notation as string
30	
31	# Forbidden ops -- using any in solution.py f

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Read /home/infatoshi/cuda/KernelBench-Hard/problems/02_kda_cutlass/sota.py
args
{
  "file_path": "/home/infatoshi/cuda/KernelBench-Hard/problems/02_kda_cutlass/sota.py"
}
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1	"""SOTA reference for KDA forward: fla.ops.kda.chunk_kda (Triton).
2	
3	The agent's solution is forbidden from importing this module path (see
4	problem.yaml.forbidden). This file is only used by benchmark.py to draw
5	the SOTA reference line.
6	
7	If FLA's Triton kernel does not run on SM120 (Blackwell consumer-lineage --
8	some Triton kernels in FLA target Hopper TMA), is_available() returns False
9	and benchmark.py omits the SOTA variant. The H100 reference is documented
10	in problem.yaml for context.
11	"""
12	from __future__ import annotations
13	
14	import torch
15	
16	
17	def _import_fla():
18	    try:
19	        from fla.ops.kda import chunk_kda  # noqa: F401
20	        return chunk_kda
21	    except Exception:
22	        return None
23	
24	
25	def sota_forward(
26	    q: torch.Tensor,
27	    k: torch.Tensor,
28	    v: torch.Tensor,
29	    g: torch.Tensor,
30	    beta: torch.Tensor,
31	    scale: float | None = None,
32	) -> torch.Tensor:
33	    """Run FLA's Triton chunk_kda. Returns o (B, T, H, V) in v's dtype."""
34	    chunk_kda = _import_fla()
35	    if chunk_kda is None:
36	        raise RuntimeError("fla.ops.kda.chunk_kda unavailable")
37	    # FLA's chunk_kda has a richer signature (A_log, dt_bias, l2norm, gates, ...).
38	    # We need the bare forward: pass A_log/dt_bias as None, gates off, no l2norm.
39	    # The wrapper expects fp32 g; q/k/v/beta in bf16/fp16.
40	    out = chunk_kda(
41	        q=q,
42	        k=k,
43	        v=v,
44	        g=g,
45	     

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Read /home/infatoshi/cuda/KernelBench-Hard/problems/02_kda_cutlass/shapes.py
args
{
  "file_path": "/home/infatoshi/cuda/KernelBench-Hard/problems/02_kda_cutlass/shapes.py"
}
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1	"""Canonical shape sweep for KDA forward (chunk form).
2	
3	Mix of:
4	  - short-context training-step scale (T=1024)
5	  - mid-context (T=2048) which is the headline benchmark
6	  - long-context that stresses the inter-chunk recurrence (T=4096)
7	  - thin-batch decode-style (B=1, T=2048, fewer heads)
8	
9	Constraints:
10	  - T % chunk_size == 0 (chunk_size = 64)
11	  - K, V are the per-head channel dims; KDA in Kimi Linear uses K=V=128
12	"""
13	
14	SHAPES = [
15	    {"B": 2, "T": 1024, "H": 8, "K": 128, "V": 128, "CHUNK_SIZE": 64},
16	    {"B": 2, "T": 2048, "H": 8, "K": 128, "V": 128, "CHUNK_SIZE": 64},
17	    {"B": 1, "T": 4096, "H": 8, "K": 128, "V": 128, "CHUNK_SIZE": 64},
18	    {"B": 1, "T": 2048, "H": 4, "K": 128, "V": 128, "CHUNK_SIZE": 64},
19	]
20	
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args
{
  "query": "select:TodoWrite,WebFetch,WebSearch",
  "max_results": 5
}
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TodoWrite
args
{
  "todos": [
    {
      "content": "Study FLA's chunk_kda Triton kernel and reference impl",
      "activeForm": "Studying FLA's chunk_kda Triton kernel and reference impl",
      "status": "in_progress"
    },
    {
      "content": "Check GPU state and torch/triton/cuda versions",
      "activeForm": "Checking GPU state and toolchain versions",
      "status": "pending"
    },
    {
      "content": "Implement chunk-parallel KDA forward in Triton",
      "activeForm": "Implementing chunk-parallel KDA forward in Triton",
      "status": "pending"
    },
    {
      "content": "Run check.py

... (312 more chars)
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stdout (160 chars)
Todos have been modified successfully. Ensure that you continue to use the todo list to track your progress. Please proceed with the current tasks if applicable
assistant
Bash
args
{
  "command": "nvidia-smi --query-gpu=name,memory.free,utilization.gpu,utilization.memory --format=csv",
  "description": "Check GPU state"
}
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name, memory.free [MiB], utilization.gpu [%], utilization.memory [%]
NVIDIA RTX PRO 6000 Blackwell Workstation Edition, 96493 MiB, 0 %, 19 %
assistant
Bash
args
{
  "command": "uv run python -c \"import torch; print('torch:', torch.__version__, 'cuda:', torch.version.cuda); import triton; print('triton:', triton.__version__); print('device:', torch.cuda.get_device_name(), 'cc:', torch.cuda.get_device_capability())\"",
  "description": "Check torch/triton versions"
}
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torch: 2.11.0+cu130 cuda: 13.0
triton: 3.6.0
device: NVIDIA RTX PRO 6000 Blackwell Workstation Edition cc: (12, 0)
assistant
Bash
args
{
  "command": "uv run python -c \"import fla; print(fla.__version__); import fla.ops.kda; print(fla.ops.kda.__file__)\"",
  "description": "Check FLA install"
}
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stdout (102 chars)
0.5.0
/home/infatoshi/cuda/KernelBench-Hard/.venv/lib/python3.11/site-packages/fla/ops/kda/__init__.py
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args
{
  "command": "ls -la /home/infatoshi/cuda/KernelBench-Hard/.venv/lib/python3.11/site-packages/fla/ops/kda/",
  "description": "List KDA implementation files"
}
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drwxrwxr-x infatoshi infatoshi 4.0 KB Sat Apr 25 22:52:30 2026 .
drwxrwxr-x infatoshi infatoshi 4.0 KB Sat Apr 25 22:52:29 2026 ..
.rw-rw-r-- infatoshi infatoshi 441 B  Fri Apr 24 23:38:15 2026 __init__.py
drwxrwxr-x infatoshi infatoshi 4.0 KB Sat Apr 25 22:52:30 2026 __pycache__
drwxrwxr-x infatoshi infatoshi 4.0 KB Sat Apr 25 22:52:31 2026 backends
.rw-rw-r-- infatoshi infatoshi  16 KB Fri Apr 24 23:38:15 2026 chunk.py
.rw-rw-r-- infatoshi infatoshi  19 KB Fri Apr 24 23:38:15 2026 chunk_bwd.py
.rw-rw-r-- infatoshi infatoshi 4.3 KB Fri Apr 24 23:38:15 2026 chunk_fwd.py
.rw-rw-r-- infatoshi infatoshi  35 KB Fri Apr 24 23:38:15 2026 chunk_intra.py
.rw-rw-r-- infatoshi infatoshi 5.1 KB Fri Apr 24 23:38:15 2026 chunk_intra_token_parallel.py
.rw-rw-r-- infatoshi infatoshi  15 KB Fri Apr 24 23:38:15 2026 fused_recurrent.py
.rw-rw-r-- infatoshi infatoshi  14 KB Fri Apr 24 23:38:15 2026 gate.py
.rw-rw-r-- infatoshi infatoshi 6.2 KB Fri Apr 24 23:38:15 2026 naive.py
.rw-rw-r-- infatoshi infatoshi  12 KB Fri Apr 24 23:38:15 2026 wy_fast.py
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Read /home/infatoshi/cuda/KernelBench-Hard/.venv/lib/python3.11/site-packages/fla/ops/kda/__init__.py
args
{
  "file_path": "/home/infatoshi/cuda/KernelBench-Hard/.venv/lib/python3.11/site-packages/fla/ops/kda/__init__.py"
}
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1	# Copyright (c) 2023-2026, Songlin Yang, Yu Zhang, Zhiyuan Li
2	#
3	# This source code is licensed under the MIT license found in the
4	# LICENSE file in the root directory of this source tree.
5	# For a list of all contributors, visit:
6	#   https://github.com/fla-org/flash-linear-attention/graphs/contributors
7	
8	from .chunk import chunk_kda
9	from .fused_recurrent import fused_recurrent_kda
10	
11	__all__ = [
12	    "chunk_kda",
13	    "fused_recurrent_kda",
14	]
15	
assistant
Read /home/infatoshi/cuda/KernelBench-Hard/.venv/lib/python3.11/site-packages/fla/ops/kda/naive.py
args
{
  "file_path": "/home/infatoshi/cuda/KernelBench-Hard/.venv/lib/python3.11/site-packages/fla/ops/kda/naive.py"
}
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1	# Copyright (c) 2023-2026, Songlin Yang, Yu Zhang, Zhiyuan Li
2	#
3	# This source code is licensed under the MIT license found in the
4	# LICENSE file in the root directory of this source tree.
5	# For a list of all contributors, visit:
6	#   https://github.com/fla-org/flash-linear-attention/graphs/contributors
7	
8	import torch
9	from einops import rearrange
10	
11	
12	def naive_recurrent_kda(
13	    q: torch.Tensor,
14	    k: torch.Tensor,
15	    v: torch.Tensor,
16	    g: torch.Tensor,
17	    beta: torch.Tensor,
18	    scale: float | None = None,
19	    initial_state: torch.Tensor | None = None,
20	    output_final_state: bool = False,
21	):
22	    r"""
23	    Args:
24	        q (torch.Tensor):
25	            Queries of shape ``[B, T, H, K]``.
26	        k (torch.Tensor):
27	            Keys of shape ``[B, T, H, K]``.
28	        v (torch.Tensor):
29	            Values of shape ``[B, T, HV, V]``. ``HV`` must be divisible by ``H``.
30	        g (torch.Tensor):
31	            Per-dimension decay gates (log-space) of shape ``[B, T, HV, K]``.
32	        beta (torch.Tensor):
33	            Beta scalars of shape ``[B, T, HV]``.
34	        scale (Optional[float]):
35	            Scale factor. Defaults to ``1 / sqrt(K)``.
36	        initial_state (Optional[torch.Tensor]):
37	            Initial state of shape ``[B, HV, K, V]``.
38	        output_final_state (bool):
39	            Whether to return the final state.
40	
41	    Returns:
42	        A tuple ``(o, S)`` where ``o`` has 

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Read /home/infatoshi/cuda/KernelBench-Hard/.venv/lib/python3.11/site-packages/fla/ops/kda/chunk.py
args
{
  "file_path": "/home/infatoshi/cuda/KernelBench-Hard/.venv/lib/python3.11/site-packages/fla/ops/kda/chunk.py"
}
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1	# Copyright (c) 2023-2026, Songlin Yang, Yu Zhang, Zhiyuan Li
2	#
3	# This source code is licensed under the MIT license found in the
4	# LICENSE file in the root directory of this source tree.
5	# For a list of all contributors, visit:
6	#   https://github.com/fla-org/flash-linear-attention/graphs/contributors
7	
8	# Related files are modified and supported by the Moonshot AI Team
9	
10	import torch
11	
12	from fla.modules.l2norm import l2norm_bwd, l2norm_fwd
13	from fla.ops.backends import dispatch
14	from fla.ops.cp import FLACPContext
15	from fla.ops.kda.chunk_bwd import chunk_kda_bwd
16	from fla.ops.kda.chunk_fwd import chunk_kda_fwd
17	from fla.ops.utils.index import prepare_chunk_indices
18	from fla.utils import autocast_custom_bwd, autocast_custom_fwd, input_guard
19	
20	
21	class ChunkKDAFunction(torch.autograd.Function):
22	    @staticmethod
23	    @input_guard
24	    @autocast_custom_fwd
25	    def forward(
26	        ctx,
27	        q: torch.Tensor,
28	        k: torch.Tensor,
29	        v: torch.Tensor,
30	        g: torch.Tensor,
31	        beta: torch.Tensor,
32	        A_log: torch.Tensor,
33	        dt_bias: torch.Tensor,
34	        scale: float,
35	        initial_state: torch.Tensor,
36	        output_final_state: bool = False,
37	        use_qk_l2norm_in_kernel: bool = False,
38	        use_gate_in_kernel: bool = False,
39	        cu_seqlens: torch.LongTensor | None = None,
40	        cu_seqlens_cpu: torch.LongTensor | None = None,
41	        safe_gate: 

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assistant
Read /home/infatoshi/cuda/KernelBench-Hard/.venv/lib/python3.11/site-packages/fla/ops/kda/chunk_fwd.py
args
{
  "file_path": "/home/infatoshi/cuda/KernelBench-Hard/.venv/lib/python3.11/site-packages/fla/ops/kda/chunk_fwd.py"
}
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1	# Copyright (c) 2023-2026, Songlin Yang, Yu Zhang, Zhiyuan Li
2	#
3	# This source code is licensed under the MIT license found in the
4	# LICENSE file in the root directory of this source tree.
5	# For a list of all contributors, visit:
6	#   https://github.com/fla-org/flash-linear-attention/graphs/contributors
7	
8	import torch
9	
10	from fla.ops.common.chunk_delta_h import chunk_gated_delta_rule_fwd_h
11	from fla.ops.cp import FLACPContext
12	from fla.ops.cp.chunk_delta_h import chunk_gated_delta_rule_fwd_h_pre_process, compress_h0
13	from fla.ops.gla.chunk import chunk_gla_fwd_o_gk
14	from fla.ops.kda.chunk_intra import chunk_kda_fwd_intra
15	from fla.ops.kda.gate import kda_gate_chunk_cumsum
16	from fla.ops.utils import chunk_local_cumsum
17	from fla.ops.utils.constant import RCP_LN2
18	
19	
20	def chunk_kda_fwd(
21	    q: torch.Tensor,
22	    k: torch.Tensor,
23	    v: torch.Tensor,
24	    g: torch.Tensor,
25	    beta: torch.Tensor,
26	    scale: float,
27	    initial_state: torch.Tensor,
28	    output_final_state: bool,
29	    cu_seqlens: torch.LongTensor | None = None,
30	    cu_seqlens_cpu: torch.LongTensor | None = None,
31	    chunk_indices: torch.LongTensor | None = None,
32	    chunk_size: int = 64,
33	    safe_gate: bool = False,
34	    lower_bound: float | None = None,
35	    use_gate_in_kernel: bool = False,
36	    A_log: torch.Tensor | None = None,
37	    dt_bias: torch.Tensor | None = None,
38	    disable_recompute: bool = False,
39	    return_intermediate_

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Bash
args
{
  "command": "ls /home/infatoshi/cuda/KernelBench-Hard/.venv/lib/python3.11/site-packages/fla/ops/common/ | head -20",
  "description": "List common FLA ops"
}
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stdout (182 chars)
__init__.py
__pycache__
backends
chunk_delta_h.py
chunk_h.py
chunk_h_parallel.py
chunk_h_split.py
chunk_o.py
chunk_scaled_dot_kkt.py
fused_chunk.py
fused_recurrent.py
intracard_cp.py
assistant
Read /home/infatoshi/cuda/KernelBench-Hard/.venv/lib/python3.11/site-packages/fla/ops/kda/chunk_intra.py
args
{
  "file_path": "/home/infatoshi/cuda/KernelBench-Hard/.venv/lib/python3.11/site-packages/fla/ops/kda/chunk_intra.py",
  "limit": 100
}
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1	# Copyright (c) 2023-2026, Songlin Yang, Yu Zhang, Zhiyuan Li
2	#
3	# This source code is licensed under the MIT license found in the
4	# LICENSE file in the root directory of this source tree.
5	# For a list of all contributors, visit:
6	#   https://github.com/fla-org/flash-linear-attention/graphs/contributors
7	
8	import torch
9	import triton
10	import triton.language as tl
11	
12	from fla.ops.kda.chunk_intra_token_parallel import chunk_kda_fwd_intra_token_parallel
13	from fla.ops.kda.wy_fast import recompute_w_u_fwd
14	from fla.ops.utils import prepare_chunk_indices
15	from fla.ops.utils.op import exp2, gather
16	from fla.utils import IS_GATHER_SUPPORTED, IS_TF32_SUPPORTED, autotune_cache_kwargs
17	
18	if IS_TF32_SUPPORTED:
19	    SOLVE_TRIL_DOT_PRECISION = tl.constexpr('tf32')
20	else:
21	    SOLVE_TRIL_DOT_PRECISION = tl.constexpr('ieee')
22	
23	################################################################################
24	# Fused inter + solve_tril kernel: compute off-diagonal Akk and solve in one pass
25	################################################################################
26	
27	
28	@triton.heuristics({
29	    'IS_VARLEN': lambda args: args['cu_seqlens'] is not None,
30	})
31	@triton.autotune(
32	    configs=[
33	        triton.Config({'BK': BK}, num_warps=num_warps)
34	        for BK in [32, 64]
35	        for num_warps in [1, 2, 4]
36	    ],
37	    key=["H", "HV", "K", "BC"],
38	    **autotune_cache_kwargs,
39	)
40	@triton.jit(do_not_specialize=['T

... (1794 more chars)
assistant
TodoWrite
args
{
  "todos": [
    {
      "content": "Study FLA's chunk_kda Triton kernel and reference impl",
      "activeForm": "Studying FLA's chunk_kda Triton kernel and reference impl",
      "status": "in_progress"
    },
    {
      "content": "Check GPU state and torch/triton/cuda versions",
      "activeForm": "Checking GPU state and toolchain versions",
      "status": "completed"
    },
    {
      "content": "Implement chunk-parallel KDA forward in Triton",
      "activeForm": "Implementing chunk-parallel KDA forward in Triton",
      "status": "pending"
    },
    {
      "content": "Run check.

... (314 more chars)
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stdout (160 chars)
Todos have been modified successfully. Ensure that you continue to use the todo list to track your progress. Please proceed with the current tasks if applicable
assistant
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Let me check the hardware peak numbers and then look at more parts of FLA's implementation.
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Read /home/infatoshi/cuda/KernelBench-Hard/src/hardware/rtx_pro_6000.py
args
{
  "file_path": "/home/infatoshi/cuda/KernelBench-Hard/src/hardware/rtx_pro_6000.py"
}
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1	"""RTX PRO 6000 Blackwell Workstation — SM120, consumer-lineage Blackwell.
2	
3	Peak tensor-core throughputs are dense-matrix advertised peaks. Actual kernels
4	will see 60-85% of peak on well-tuned code.
5	"""
6	from dataclasses import dataclass
7	
8	
9	@dataclass(frozen=True)
10	class HardwareTarget:
11	    name: str
12	    sm: str
13	    vram_gb: int
14	    peak_bandwidth_gb_s: float  # DRAM
15	    peak_tflops_dense: dict[str, float]  # dtype -> TFLOPS
16	
17	
18	RTX_PRO_6000 = HardwareTarget(
19	    name="RTX PRO 6000 Blackwell Workstation",
20	    sm="sm_120a",
21	    vram_gb=96,
22	    peak_bandwidth_gb_s=1800.0,
23	    peak_tflops_dense={
24	        "fp4": 800.0,
25	        "nvfp4": 800.0,
26	        "mxfp4": 800.0,
27	        "fp6": 800.0,
28	        "fp8": 400.0,
29	        "bf16": 200.0,
30	        "fp16": 200.0,
31	        "tf32": 100.0,
32	        "fp32": 12.0,  # non-tensor-core SIMT fp32
33	        "int8": 400.0,
34	        "int4": 800.0,
35	    },
36	)
37	
assistant
Read /home/infatoshi/cuda/KernelBench-Hard/.venv/lib/python3.11/site-packages/fla/ops/common/chunk_delta_h.py
args
{
  "file_path": "/home/infatoshi/cuda/KernelBench-Hard/.venv/lib/python3.11/site-packages/fla/ops/common/chunk_delta_h.py",
  "limit": 100
}
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tool
stdout (3517 chars) — TRUNCATED
1	# Copyright (c) 2023-2026, Songlin Yang, Yu Zhang, Zhiyuan Li
2	#
3	# This source code is licensed under the MIT license found in the
4	# LICENSE file in the root directory of this source tree.
5	# For a list of all contributors, visit:
6	#   https://github.com/fla-org/flash-linear-attention/graphs/contributors
7	
8	import torch
9	import triton
10	import triton.language as tl
11	
12	from fla.ops.backends import dispatch
13	from fla.ops.utils import prepare_chunk_indices, prepare_chunk_offsets
14	from fla.ops.utils.op import exp, exp2
15	from fla.utils import IS_NVIDIA_HOPPER, USE_CUDA_GRAPH, autotune_cache_kwargs, check_shared_mem
16	
17	NUM_WARPS = [2, 4] if IS_NVIDIA_HOPPER else [2, 4, 8, 16]
18	
19	
20	@triton.heuristics({
21	    'USE_G': lambda args: args['g'] is not None,
22	    'USE_GK': lambda args: args['gk'] is not None,
23	    'USE_INITIAL_STATE': lambda args: args['h0'] is not None,
24	    'STORE_FINAL_STATE': lambda args: args['ht'] is not None,
25	    'SAVE_NEW_VALUE': lambda args: args['v_new'] is not None,
26	    'IS_VARLEN': lambda args: args['cu_seqlens'] is not None,
27	})
28	@triton.autotune(
29	    configs=[
30	        triton.Config({'BV': BV}, num_warps=num_warps, num_stages=num_stages)
31	        for num_warps in [2, 4]
32	        for num_stages in ([2, 3, 4] if check_shared_mem('ampere') else [2, 1])
33	        for BV in ([32, 64] if check_shared_mem('ada') else [32])
34	    ],
35	    key=['H', 'HV', 'K', 'V', 'BT', 'USE_EXP2', 'TRANSPOSE_STATE'],
36	

... (2017 more chars)
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in 1out 46cache_r 72948cache_w 10596
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Read /home/infatoshi/cuda/KernelBench-Hard/.venv/lib/python3.11/site-packages/fla/ops/kda/wy_fast.py
args
{
  "file_path": "/home/infatoshi/cuda/KernelBench-Hard/.venv/lib/python3.11/site-packages/fla/ops/kda/wy_fast.py"
}
in 1out 46cache_r 72948cache_w 10596
tool
stdout (13260 chars) — TRUNCATED
1	# Copyright (c) 2023-2026, Songlin Yang, Yu Zhang, Zhiyuan Li
2	#
3	# This source code is licensed under the MIT license found in the
4	# LICENSE file in the root directory of this source tree.
5	# For a list of all contributors, visit:
6	#   https://github.com/fla-org/flash-linear-attention/graphs/contributors
7	
8	import torch
9	import triton
10	import triton.language as tl
11	
12	from fla.ops.utils import prepare_chunk_indices
13	from fla.ops.utils.op import exp2
14	from fla.utils import autotune_cache_kwargs, check_shared_mem
15	
16	
17	@triton.heuristics({
18	    'STORE_QG': lambda args: args['qg'] is not None,
19	    'STORE_KG': lambda args: args['kg'] is not None,
20	    'IS_VARLEN': lambda args: args['cu_seqlens'] is not None,
21	})
22	@triton.autotune(
23	    configs=[
24	        triton.Config({}, num_warps=num_warps, num_stages=num_stages)
25	        for num_warps in [2, 4, 8]
26	        for num_stages in [2, 3, 4]
27	    ],
28	    key=['H', 'HV', 'K', 'V', 'BT', 'BK', 'BV', 'IS_VARLEN'],
29	    **autotune_cache_kwargs,
30	)
31	@triton.jit(do_not_specialize=['T'])
32	def recompute_w_u_fwd_kda_kernel(
33	    q,
34	    k,
35	    qg,
36	    kg,
37	    v,
38	    beta,
39	    w,
40	    u,
41	    A,
42	    gk,
43	    cu_seqlens,
44	    chunk_indices,
45	    T,
46	    H: tl.constexpr,
47	    HV: tl.constexpr,
48	    K: tl.constexpr,
49	    V: tl.constexpr,
50	    BT: tl.constexpr,
51	    BK: tl.constexpr,
52	    BV: tl.constexpr,
53	    STORE_QG: tl.constexpr,
54	    STO

... (11760 more chars)
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in 1out 70cache_r 83544cache_w 10963
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Read /home/infatoshi/cuda/KernelBench-Hard/.venv/lib/python3.11/site-packages/fla/ops/kda/chunk_intra.py
args
{
  "file_path": "/home/infatoshi/cuda/KernelBench-Hard/.venv/lib/python3.11/site-packages/fla/ops/kda/chunk_intra.py",
  "offset": 100,
  "limit": 300
}
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tool
stdout (15445 chars) — TRUNCATED
100	    o_i = tl.arange(0, BC)
101	    m_tc1 = (i_tc1 + o_i) < T
102	    m_tc2 = (i_tc2 + o_i) < T
103	    m_tc3 = (i_tc3 + o_i) < T
104	
105	    b_Aqk10 = tl.zeros([BC, BC], dtype=tl.float32)
106	    b_Akk10 = tl.zeros([BC, BC], dtype=tl.float32)
107	
108	    b_Aqk20 = tl.zeros([BC, BC], dtype=tl.float32)
109	    b_Akk20 = tl.zeros([BC, BC], dtype=tl.float32)
110	    b_Aqk21 = tl.zeros([BC, BC], dtype=tl.float32)
111	    b_Akk21 = tl.zeros([BC, BC], dtype=tl.float32)
112	
113	    b_Aqk30 = tl.zeros([BC, BC], dtype=tl.float32)
114	    b_Akk30 = tl.zeros([BC, BC], dtype=tl.float32)
115	    b_Aqk31 = tl.zeros([BC, BC], dtype=tl.float32)
116	    b_Akk31 = tl.zeros([BC, BC], dtype=tl.float32)
117	    b_Aqk32 = tl.zeros([BC, BC], dtype=tl.float32)
118	    b_Akk32 = tl.zeros([BC, BC], dtype=tl.float32)
119	
120	    ################################################################################
121	    # off-diagonal blocks
122	    ################################################################################
123	    for i_k in range(tl.cdiv(K, BK)):
124	        o_k = i_k * BK + tl.arange(0, BK)
125	        m_k = o_k < K
126	
127	        p_k0 = tl.make_block_ptr(k, (T, K), (H*K, 1), (i_tc0, i_k * BK), (BC, BK), (1, 0))
128	        p_g0 = tl.make_block_ptr(g, (T, K), (HV*K, 1), (i_tc0, i_k * BK), (BC, BK), (1, 0))
129	        b_k0 = tl.load(p_k0, boundary_check=(0, 1)).to(tl.float32)
130	        b_g0 = tl.load(p_g0, boundary_check=(0, 1)).to(tl.float32)
131	
132	        if i_tc1 <

... (13945 more chars)
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in 1out 51cache_r 94507cache_w 9021
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Read /home/infatoshi/cuda/KernelBench-Hard/.venv/lib/python3.11/site-packages/fla/ops/kda/chunk_intra_token_parallel.py
args
{
  "file_path": "/home/infatoshi/cuda/KernelBench-Hard/.venv/lib/python3.11/site-packages/fla/ops/kda/chunk_intra_token_parallel.py"
}
in 1out 51cache_r 94507cache_w 9021
tool
stdout (5834 chars) — TRUNCATED
1	# Copyright (c) 2023-2026, Songlin Yang, Yu Zhang, Zhiyuan Li
2	#
3	# This source code is licensed under the MIT license found in the
4	# LICENSE file in the root directory of this source tree.
5	# For a list of all contributors, visit:
6	#   https://github.com/fla-org/flash-linear-attention/graphs/contributors
7	
8	# Token-parallel implementation of KDA intra chunk kernel
9	
10	import torch
11	import triton
12	import triton.language as tl
13	
14	from fla.ops.utils.op import exp2
15	from fla.utils import autotune_cache_kwargs
16	
17	
18	@triton.heuristics({
19	    'IS_VARLEN': lambda args: args['cu_seqlens'] is not None,
20	})
21	@triton.autotune(
22	    configs=[
23	        triton.Config({'BH': BH}, num_warps=num_warps)
24	        for BH in [1, 2, 4, 8]
25	        for num_warps in [1, 2, 4, 8]
26	    ],
27	    key=["K", "H", "HV"],
28	    **autotune_cache_kwargs,
29	)
30	@triton.jit(do_not_specialize=['T', 'N'])
31	def chunk_kda_fwd_kernel_intra_token_parallel(
32	    q,
33	    k,
34	    g,
35	    beta,
36	    Aqk,
37	    Akk,
38	    scale,
39	    cu_seqlens,
40	    N,
41	    T,
42	    H: tl.constexpr,
43	    HV: tl.constexpr,
44	    K: tl.constexpr,
45	    BT: tl.constexpr,
46	    BC: tl.constexpr,
47	    BH: tl.constexpr,
48	    IS_VARLEN: tl.constexpr,
49	):
50	    i_tg, i_hg = tl.program_id(0), tl.program_id(1)
51	
52	    if IS_VARLEN:
53	        i_n = 0
54	        left, right = 0, N
55	
56	        # Unrolled binary search (max B=2^32)
57	        # We can limit iterati

... (4334 more chars)
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in 1out 44cache_r 103528cache_w 6323
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Let me first verify the reference works on this hardware, then start drafting.
in 1out 44cache_r 103528cache_w 6323
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Bash
args
{
  "command": "<512 chars \u2014 see below>",
  "description": "Verify reference runs"
}
command (512 chars)
cd /home/infatoshi/cuda/KernelBench-Hard/problems/02_kda_cutlass && uv run python -c "
import sys
sys.path.insert(0, '.')
import torch
import reference
device = torch.device('cuda:0')
m = reference.Model(*reference.get_init_inputs()).to(device).eval()
inputs = [t.to(device) if hasattr(t, 'to') else t for t in reference.get_inputs()]
with torch.no_grad():
    o = m(*inputs)
print('shape:', o.shape, 'dtype:', o.dtype)
print('o stats:', o.float().min().item(), o.float().max().item(), o.float().mean().item())
"
in 1out 44cache_r 103528cache_w 6323
tool
stdout (120 chars)
shape: torch.Size([2, 1024, 8, 128]) dtype: torch.bfloat16
o stats: -0.01116943359375 0.01171875 -1.1375359463272616e-06
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in 1out 46cache_r 109851cache_w 7146
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Now let me write the initial Triton implementation. I'll go with a clear baseline first.
in 1out 46cache_r 109851cache_w 7146
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Write /home/infatoshi/cuda/KernelBench-Hard/problems/02_kda_cutlass/solution.py
diff (293 lines — TRUNCATED)
--- /dev/null
+++ b//home/infatoshi/cuda/KernelBench-Hard/problems/02_kda_cutlass/solution.py
@@ -0,0 +1,290 @@
+"""Custom KDA forward (chunk form) using Triton kernels for SM120.
+
+Implementation notes:
+  - g is rescaled by RCP_LN2 so we can use exp2 throughout (faster than exp).
+  - In-chunk cumsum on g is fused into the intra kernel via tl.cumsum.
+  - Phase 1 (intra): per-chunk forward substitution on the (I + L) factor and
+    materialize the chunk-local Akk_inv, w, u tensors.
+  - Phase 2 (inter): sequential per-(b, h) loop over chunks computing the state
+    h and the output o, with the V dim split into BV-tiles for parallelism.
+"""
+from __future__ import annotations
+
+import torch
+import torch.nn as nn
+import triton
+import triton.language as tl
+
+RCP_LN2 = 1.4426950408889634  # log2(e), so exp(x) = exp2(x * RCP_LN2)
+
+
+@triton.jit
+def _kda_intra_kernel(
+    k_ptr,
+    v_ptr,
+    g_in_ptr,
+    g_out_ptr,
+    beta_ptr,
+    A_ptr,
+    w_ptr,
+    u_ptr,
+    T,
+    H: tl.constexpr,
+    K: tl.constexpr,
+    V: tl.constexpr,
+    BT: tl.constexpr,
+    SCALE_LOG: tl.constexpr,
+):
+    """Per-chunk preparation: cumsum g; build Akk_inv*beta_col; w, u.
+
+    Grid: (B*H, NT)
+    """
+    i_bh = tl.program_id(0)
+    i_n = tl.program_id(1)
+    i_b = i_bh // H
+    i_h = i_bh % H
+    NT = T // BT
+
+    offs_t = tl.arange(0, BT)
+    offs_k = tl.arange(0, K)
+    offs_v = tl.arange(0, V)
+
+    # ---------- Pointers ----------
+    # k, g: (B, T, H, K) — strides (T*H*K, H*K, K, 1)
+    k_base = i_b * T * H * K + i_n * BT * H * K + i_h * K
+    g_base = k_base
+    # v: (B, T, H, V)
+    v_base = i_b * T * H * V + i_n * BT * H * V + i_h * V
+    # beta: (B, T, H)
+    beta_base = i_b * T * H + i_n * BT * H + i_h
+    # A: (B, NT, H, BT, BT) contiguous on the last two dims
+    A_base = i_b * NT * H * BT * BT + i_n * H * BT * BT + i_h * BT * BT
+
+    # ---------- Load k, g, beta ----------
+    kg_ptrs_t = offs_t[:, None] * H * K + offs_k[None, :]
+    b_k = tl.load(k_ptr + k_base + kg_ptrs_t)            # (BT, K) bf16
+    b_g_raw = tl.load(g_in_ptr + g_base + kg_ptrs_t).to(tl.float32) * SCALE_LOG
+    b_g = tl.cumsum(b_g_raw, axis=0)                      # (BT, K) fp32
+
+    # Save the cumsumed g back to global (used by inter kernel).
+    tl.store(g_out_ptr + g_base + kg_ptrs_t, b_g)
+
+    b_beta = tl.load(beta_ptr + beta_base + offs_t * H).to(tl.float32)  # (BT,)
+
+    # ---------- Akk_raw = -beta_row * (k*exp(g)) @ (k*exp(-g)).T ----------
+    b_eg = tl.exp2(b_g)             # (BT, K) fp32
+    b_eng = tl.exp2(-b_g)           # (BT, K) fp32
+    b_kf = b_k.to(tl.float32) * b_eg
+    b_kg = b_k.to(tl.float32) * b_eng
+    b_A = tl.dot(b_kf.to(b_k.dtype), tl.trans(b_kg).to(b_k.dtype))  # (BT, BT) fp32
+    mask_strict_lower = offs_t[:, None] > offs_t[None, :]
+    b_A = tl.where(mask_strict_lower, -b_A * b_beta[:, None], 0.0)
+
+    # ---------- Forward substitute (BT iterations) ----------
+    # for i in 1..BT-1: A[i, :i] += sum_m A[i, m] * A[m, :i]   for m < i
+    for i in tl.static_range(1, BT):
+        is_row = (offs_t == i)
+        # row i of A (BT,)
+        row_i = tl.sum(tl.where(is_row[:, None], b_A, 0.0), axis=0)
+        # (row_i @ A)[j] = sum_m row_i[m] * A[m, j]
+        update = tl.sum(row_i[:, None] * b_A, axis=0)
+        # write only the lower part of row i
+        write_mask = is_row[:, None] & (offs_t[None, :] < i)
+        b_A = tl.where(write_mask, b_A + update[None, :], b_A)
+
+    # Add identity on the diagonal
+    b_A = tl.where(offs_t[:, None] == offs_t[None, :], b_A + 1.0, b_A)
+    # Multiply by beta_col: A *= beta[None, :]
+    b_A = b_A * b_beta[None, :]
+
+    # ---------- Store A_inv (fp32 for downstream precision) ----------
+    A_ptrs = offs_t[:, None] * BT + offs_t[None, :]
+    tl.store(A_ptr + A_base + A_ptrs, b_A)
+
+    # ---------- w = A @ (g.exp() * k) ----------
+    b_w = tl.dot(b_A.to(b_k.dtype), b_kf.to(b_k.dtype))   # (BT, K) fp32
+    tl.store(w_ptr + k_base + kg_ptrs_t, b_w.to(b_k.dtype))
+
+    # ---------- u = A @ v ----------
+    v_ptrs_t = offs_t[:, None] * H * V + offs_v[None, :]
+    b_v = tl.load(v_ptr + v_base + v_ptrs_t)              # (BT, V) bf16
+    b_u = tl.dot(b_A.to(b_v.dtype), b_v)                  # (BT, V) fp32
+    tl.store(u_ptr + v_base + v_ptrs_t, b_u.to(b_v.dtype))
+
+
+@triton.jit
+def _kda_inter_kernel(
+    q_ptr,
+    k_ptr,
+    g_ptr,
+    w_ptr,
+    u_ptr,
+    o_ptr,
+    scale,
+    T,
+    H: tl.constexpr,
+    K: tl.constexpr,
+    V: tl.constexpr,
+    BT: tl.constexpr,
+    BV: tl.constexpr,
+    SCALE_LOG: tl.constexpr,
+):
+    """Inter-chunk recurrence: maintain state S, compute o.
+
+    Grid: (B*H, V/BV)
+    Each program handles one (b, h) pair and one V-slice. Sequential over chunks.
+    """
+    i_bh = tl.program_id(0)
+    i_v = tl.program_id(1)
+    i_b = i_bh // H
+    i_h = i_bh % H
+    NT = T // BT
+
+    offs_t = tl.arange(0, BT)
+    offs_k = tl.arange(0, K)
+    offs_v = tl.arange(0, BV)
+
+    v_lo = i_v * BV
+
+    # Strict-upper mask for Aqk (zero out strict-upper, keep diag and below)
+    mask_su = offs_t[:, None] < offs_t[None, :]
+
+    # State S: (K, BV) fp32
+    b_S = tl.zeros((K, BV), dtype=tl.float32)
+
+    for i_n in range(NT):
+        # Pointers
+        k_base = i_b * T * H * K + i_n * BT * H * K + i_h * K
+        v_base = i_b * T * H * V + i_n * BT * H * V + i_h * V + v_lo
+
+        kg_ptrs_t = offs_t[:, None] * H * K + offs_k[None, :]
+        v_ptrs_t = offs_t[:, None] * H * V + offs_v[None, :]
+
+        # Load q, k, g, w, u_slice
+        b_q = tl.load(q_ptr + k_base + kg_ptrs_t)              # (BT, K) bf16
+        b_k = tl.load(k_ptr + k_base + kg_ptrs_t)              # (BT, K) bf16
+        b_g = tl.load(g_ptr + k_base + kg_ptrs_t)              # (BT, K) fp32
+        b_w = tl.load(w_ptr + k_base + kg_ptrs_t)              # (BT, K) bf16
+        b_u = tl.load(u_ptr + v_base + v_ptrs_t)               # (BT, BV) bf16
+
+ 

... (4241 more chars)
args
{
  "file_path": "/home/infatoshi/cuda/KernelBench-Hard/problems/02_kda_cutlass/solution.py",
  "content": "<9839 chars \u2014 see diff>"
}
in 1out 46cache_r 109851cache_w 7146
tool
stdout (169 chars)
File created successfully at: /home/infatoshi/cuda/KernelBench-Hard/problems/02_kda_cutlass/solution.py (file state is current in your context — no need to Read it back)
assistant
TodoWrite
args
{
  "todos": [
    {
      "content": "Study FLA's chunk_kda Triton kernel and reference impl",
      "activeForm": "Studying FLA's chunk_kda Triton kernel and reference impl",
      "status": "completed"
    },
    {
      "content": "Check GPU state and torch/triton/cuda versions",
      "activeForm": "Checking GPU state and toolchain versions",
      "status": "completed"
    },
    {
      "content": "Implement chunk-parallel KDA forward in Triton",
      "activeForm": "Implementing chunk-parallel KDA forward in Triton",
      "status": "in_progress"
    },
    {
      "content": "Run chec

... (316 more chars)
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tool
stdout (160 chars)
Todos have been modified successfully. Ensure that you continue to use the todo list to track your progress. Please proceed with the current tasks if applicable
assistant
Let me run a smoke test to see if the kernel compiles and produces sensible output.
in 1out 2cache_r 130191cache_w 417
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Bash
args
{
  "command": "<896 chars \u2014 see below>",
  "description": "Smoke test solution"
}
command (896 chars)
uv run python -c "
import sys
sys.path.insert(0, '.')
import torch
import reference
import solution

device = torch.device('cuda:0')
ref_m = reference.Model(*reference.get_init_inputs()).to(device).eval()
sol_m = solution.Model(*solution.get_init_inputs()).to(device).eval()

torch.manual_seed(42)
inputs = [t.to(device) if hasattr(t, 'to') else t for t in reference.get_inputs()]
with torch.no_grad():
    ref_out = ref_m(*inputs)
    sol_out = sol_m(*inputs)
print('ref:', ref_out.shape, ref_out.dtype, 'sol:', sol_out.shape, sol_out.dtype)
diff = (ref_out.float() - sol_out.float()).abs()
print('max abs diff:', diff.max().item(), 'mean abs diff:', diff.mean().item())
print('ref max:', ref_out.float().abs().max().item(), 'sol max:', sol_out.float().abs().max().item())
print('ref[0,0,0,:5]:', ref_out[0,0,0,:5].tolist())
print('sol[0,0,0,:5]:', sol_out[0,0,0,:5].tolist())
" 2>&1 | head -100
in 1out 2cache_r 130191cache_w 417
subagent · 0 events · 0 tools
tool
stdout (472 chars)
ref: torch.Size([2, 1024, 8, 128]) torch.bfloat16 sol: torch.Size([2, 1024, 8, 128]) torch.bfloat16
max abs diff: 6.103515625e-05 mean abs diff: 5.398797839006875e-06
ref max: 0.01171875 sol max: 0.01171875
ref[0,0,0,:5]: [0.0002288818359375, -0.000102996826171875, -3.2901763916015625e-05, 0.000164031982421875, -6.379559636116028e-08]
sol[0,0,0,:5]: [0.00022792816162109375, -0.00010251998901367188, -3.2901763916015625e-05, 0.000164031982421875, -6.379559636116028e-08]
assistant
in 1out 42cache_r 130608cache_w 830
assistant
Bash
args
{
  "command": "uv run python check.py 2>&1 | tail -30",
  "description": "Run check.py"
}
in 1out 42cache_r 130608cache_w 830
subagent · 0 events · 0 tools
tool
stdout (4 chars)
PASS
assistant
in 1out 56cache_r 131438cache_w 258
assistant
Excellent — passed correctness on first try. Now let me benchmark and see where we stand.
in 1out 56cache_r 131438cache_w 258
assistant
Bash
args
{
  "command": "uv run python benchmark.py 2>&1 | tail -50",
  "description": "Run benchmark"
}
in 1out 56cache_r 131438cache_w 258
subagent · 29 events · 10 tools
tool
stdout (192 chars)
Command running in background with ID: b6c9yuro1. Output is being written to: /tmp/claude-1002/-home-infatoshi-cuda-KernelBench-Hard/400239da-f68f-4aa1-8a16-bfbfbe931013/tasks/b6c9yuro1.output
assistant
Bash
args
{
  "command": "sleep 60 && tail -70 /tmp/claude-1002/-home-infatoshi-cuda-KernelBench-Hard/400239da-f68f-4aa1-8a16-bfbfbe931013/tasks/b6c9yuro1.output",
  "description": "Wait for benchmark and show results"
}
in 1out 64cache_r 131696cache_w 295
tool
stderr (405 chars)
<tool_use_error>Blocked: sleep 60 followed by: tail -70 /tmp/claude-1002/-home-infatoshi-cuda-KernelBench-Hard/400239da-f68f-4aa1-8a16-bfbfbe931013/tasks/b6c9yuro1.output. To wait for a condition, use Monitor with an until-loop (e.g. `until <check>; do sleep 2; done`). To wait for a command you started, use run_in_background: true. Do not chain shorter sleeps to work around this block.</tool_use_error>
assistant
ToolSearch
args
{
  "query": "select:Monitor",
  "max_results": 1
}
in 1out 50cache_r 131696cache_w 679
tool
stdout (0 chars)
assistant
Bash
args
{
  "command": "until ! pgrep -f \"benchmark.py\" > /dev/null; do sleep 5; done; tail -100 /tmp/claude-1002/-home-infatoshi-cuda-KernelBench-Hard/400239da-f68f-4aa1-8a16-bfbfbe931013/tasks/b6c9yuro1.output",
  "description": "Wait for benchmark to finish",
  "run_in_background": true
}
in 6out 5cache_r 132375cache_w 2509
system — task_started
↳ subagent started
tool
stdout (192 chars)
Command running in background with ID: bld2hpt2m. Output is being written to: /tmp/claude-1002/-home-infatoshi-cuda-KernelBench-Hard/400239da-f68f-4aa1-8a16-bfbfbe931013/tasks/bld2hpt2m.output
assistant
Bash
args
{
  "command": "cat /tmp/claude-1002/-home-infatoshi-cuda-KernelBench-Hard/400239da-f68f-4aa1-8a16-bfbfbe931013/tasks/bld2hpt2m.output",
  "description": "Check benchmark results"
}
in 1out 68cache_r 134884cache_w 347
tool
stdout (31 chars)
(Bash completed with no output)
assistant
Bash
args
{
  "command": "ps aux | grep -E \"benchmark|python\" | grep -v grep | head -10",
  "description": "Check running python processes"
}
in 1out 63cache_r 135231cache_w 187
tool
stdout (23514 chars) — TRUNCATED
root        1907  0.0  0.0 126720 24796 ?        Ssl  01:49   0:00 /usr/bin/python3 /usr/share/unattended-upgrades/unattended-upgrade-shutdown --wait-for-signal
infatos+   14352  0.0  0.0 344112 95032 ?        Ssl  01:50   0:01 /home/infatoshi/hermes-agent/.venv/bin/python -m hermes_cli.main gateway run --replace
infatos+  101246  0.0  0.0  17404  2160 ?        SN   04:15   0:00 timeout 35891 codex exec -m gpt-5.5 -c model_reasoning_effort="xhigh" --dangerously-bypass-approvals-and-sandbox --skip-git-repo-check You are running inside TerrariaBench with a live Terraria/tModLoader client. Your objective is open-ended long-horizon progress: make as much concrete progress as possible toward beating Terraria.  Do not ask the user for confirmation. Do not stop just because a starter checkpoint passes. Keep playing until the external 10-hour budget ends, the game dies, or there is a fundamental unrecoverable harness failure.  Operate through the TerrariaBench helper commands appended below. Use screenshots frequently. Treat checkpoint logs as authoritative metadata, not as the full objective. Maintain a concise progress.md in the current workspace after each meaningful milestone, including current position, inventory/gear, world discoveries, deaths, blockers, and next actions.  Priorities: 1. Establish control: verify screenshots, movement, inventory, mining, placement, combat, and menu interaction. 2. Survive: avoid night deaths where possible, gather wood/stone/ore, make shelter/w

... (22014 more chars)
assistant
in 1out 42cache_r 135231cache_w 10979
assistant
Monitor
args
{
  "command": "until ! pgrep -f \"benchmark.py\" > /dev/null 2>&1; do sleep 10; done; echo \"BENCHMARK_DONE\"; tail -100 /tmp/claude-1002/-home-infatoshi-cuda-KernelBench-Hard/400239da-f68f-4aa1-8a16-bfbfbe931013/tasks/b6c9yuro1.output",
  "description": "Wait for first benchmark to complete",
  "timeout_ms": 3600000,
  "persistent": false
}
in 1out 42cache_r 135231cache_w 10979
system — task_started
↳ subagent started
tool
stdout (209 chars)
Monitor started (task bpeclfxa4, timeout 3600000ms). You will be notified on each event. Keep working — do not poll or sleep. Events may arrive while you are waiting for the user — an event is not their reply.
assistant
in 1out 41cache_r 146210cache_w 438
assistant
While the benchmark runs, let me look at potential optimizations. Let me check the file structure of the existing intra kernel.
in 1out 41cache_r 146210cache_w 438
assistant
Read /home/infatoshi/cuda/KernelBench-Hard/problems/02_kda_cutlass/solution.py
args
{
  "file_path": "/home/infatoshi/cuda/KernelBench-Hard/problems/02_kda_cutlass/solution.py",
  "offset": 1,
  "limit": 130
}
in 1out 41cache_r 146210cache_w 438
tool
stdout (4800 chars) — TRUNCATED
1	"""Custom KDA forward (chunk form) using Triton kernels for SM120.
2	
3	Implementation notes:
4	  - g is rescaled by RCP_LN2 so we can use exp2 throughout (faster than exp).
5	  - In-chunk cumsum on g is fused into the intra kernel via tl.cumsum.
6	  - Phase 1 (intra): per-chunk forward substitution on the (I + L) factor and
7	    materialize the chunk-local Akk_inv, w, u tensors.
8	  - Phase 2 (inter): sequential per-(b, h) loop over chunks computing the state
9	    h and the output o, with the V dim split into BV-tiles for parallelism.
10	"""
11	from __future__ import annotations
12	
13	import torch
14	import torch.nn as nn
15	import triton
16	import triton.language as tl
17	
18	RCP_LN2 = 1.4426950408889634  # log2(e), so exp(x) = exp2(x * RCP_LN2)
19	
20	
21	@triton.jit
22	def _kda_intra_kernel(
23	    k_ptr,
24	    v_ptr,
25	    g_in_ptr,
26	    g_out_ptr,
27	    beta_ptr,
28	    A_ptr,
29	    w_ptr,
30	    u_ptr,
31	    T,
32	    H: tl.constexpr,
33	    K: tl.constexpr,
34	    V: tl.constexpr,
35	    BT: tl.constexpr,
36	    SCALE_LOG: tl.constexpr,
37	):
38	    """Per-chunk preparation: cumsum g; build Akk_inv*beta_col; w, u.
39	
40	    Grid: (B*H, NT)
41	    """
42	    i_bh = tl.program_id(0)
43	    i_n = tl.program_id(1)
44	    i_b = i_bh // H
45	    i_h = i_bh % H
46	    NT = T // BT
47	
48	    offs_t = tl.arange(0, BT)
49	    offs_k = tl.arange(0, K)
50	    offs_v = tl.arange(0, V)
51	
52	    # ---------- Pointers ----------
53	    # k, g: (B, T, H, K) — strides (

... (3300 more chars)
assistant
Bash
args
{
  "command": "cat /tmp/claude-1002/-home-infatoshi-cuda-KernelBench-Hard/400239da-f68f-4aa1-8a16-bfbfbe931013/tasks/b6c9yuro1.output",
  "description": "Check current benchmark output"
}
in 1out 45cache_r 146648cache_w 3776
tool
stdout (31 chars)
(Bash completed with no output)
assistant
in 1out 42cache_r 150424cache_w 188
assistant
The benchmark is slow because the eager reference uses Python for-loops. Let me stop it and run a quick custom timing while keeping the monitor in case it finishes.
in 1out 42cache_r 150424cache_w 188
assistant
Bash
args
{
  "command": "<1321 chars \u2014 see below>",
  "description": "Quick timing run on solution only"
}
command (1321 chars)
uv run python -c "
import sys, time
sys.path.insert(0, '.')
import torch
import solution

device = torch.device('cuda:0')
torch.manual_seed(42)
shapes = [
    (2, 1024, 8, 128, 128, 64),
    (2, 2048, 8, 128, 128, 64),
    (1, 4096, 8, 128, 128, 64),
    (1, 2048, 4, 128, 128, 64),
]
for B, T, H, K, V, CHUNK in shapes:
    solution.B, solution.T, solution.H, solution.K, solution.V = B, T, H, K, V
    sol_m = solution.Model(B, T, H, K, V, CHUNK).to(device).eval()
    q = torch.randn(B, T, H, K, dtype=torch.bfloat16, device=device) * 0.1
    k = torch.randn(B, T, H, K, dtype=torch.bfloat16, device=device) * 0.1
    v = torch.randn(B, T, H, V, dtype=torch.bfloat16, device=device) * 0.1
    g = torch.randn(B, T, H, K, dtype=torch.float32, device=device) * 0.1 - 0.05
    beta = torch.sigmoid(torch.randn(B, T, H, dtype=torch.bfloat16, device=device))
    
    # warmup
    with torch.no_grad():
        for _ in range(3):
            sol_m(q, k, v, g, beta)
    torch.cuda.synchronize()
    
    # measure
    n_iters = 50
    t0 = time.perf_counter()
    with torch.no_grad():
        for _ in range(n_iters):
            sol_m(q, k, v, g, beta)
    torch.cuda.synchronize()
    t1 = time.perf_counter()
    ms = (t1 - t0) / n_iters * 1000
    print(f'B={B} T={T} H={H} K={K} V={V}: {ms:.3f} ms')
" 2>&1 | tail -10
in 1out 42cache_r 150424cache_w 188
tool
stdout (147 chars)
B=2 T=1024 H=8 K=128 V=128: 0.183 ms
B=2 T=2048 H=8 K=128 V=128: 0.357 ms
B=1 T=4096 H=8 K=128 V=128: 0.671 ms
B=1 T=2048 H=4 K=128 V=128: 0.334 ms
assistant
in 1out 48cache_r 150612cache_w 4909
assistant
Bash
args
{
  "command": "<129 chars \u2014 see below>",
  "description": "Check if SOTA available"
}
command (129 chars)
uv run python -c "
import sys
sys.path.insert(0, '.')
import sota
print('SOTA available:', sota.is_available())
" 2>&1 | tail -10
in 1out 48cache_r 150612cache_w 4909
system — task_started
↳ subagent started
tool
stdout (20 chars)
SOTA available: True
assistant
Bash
args
{
  "command": "<1246 chars \u2014 see below>",
  "description": "Time SOTA for comparison"
}
command (1246 chars)
uv run python -c "
import sys, time
sys.path.insert(0, '.')
import torch
import sota

device = torch.device('cuda:0')
torch.manual_seed(42)
shapes = [
    (2, 1024, 8, 128, 128, 64),
    (2, 2048, 8, 128, 128, 64),
    (1, 4096, 8, 128, 128, 64),
    (1, 2048, 4, 128, 128, 64),
]
for B, T, H, K, V, CHUNK in shapes:
    q = torch.randn(B, T, H, K, dtype=torch.bfloat16, device=device) * 0.1
    k = torch.randn(B, T, H, K, dtype=torch.bfloat16, device=device) * 0.1
    v = torch.randn(B, T, H, V, dtype=torch.bfloat16, device=device) * 0.1
    g = torch.randn(B, T, H, K, dtype=torch.float32, device=device) * 0.1 - 0.05
    beta = torch.sigmoid(torch.randn(B, T, H, dtype=torch.bfloat16, device=device))
    scale = K**-0.5
    
    # warmup
    with torch.no_grad():
        for _ in range(3):
            sota.sota_forward(q, k, v, g, beta, scale=scale)
    torch.cuda.synchronize()
    
    # measure
    n_iters = 50
    t0 = time.perf_counter()
    with torch.no_grad():
        for _ in range(n_iters):
            sota.sota_forward(q, k, v, g, beta, scale=scale)
    torch.cuda.synchronize()
    t1 = time.perf_counter()
    ms = (t1 - t0) / n_iters * 1000
    print(f'B={B} T={T} H={H} K={K} V={V}: SOTA {ms:.3f} ms')
" 2>&1 | tail -10
in 1out 65cache_r 155521cache_w 1340
subagent · 0 events · 0 tools
tool
stdout (167 chars)
B=2 T=1024 H=8 K=128 V=128: SOTA 0.327 ms
B=2 T=2048 H=8 K=128 V=128: SOTA 0.295 ms
B=1 T=4096 H=8 K=128 V=128: SOTA 0.298 ms
B=1 T=2048 H=4 K=128 V=128: SOTA 0.283 ms
assistant
in 1out 44cache_r 156861cache_w 885
assistant
Let me check the current monitor and then try some optimizations. First let me precompute Aqk and see the impact.
in 1out 44cache_r 156861cache_w 885
assistant
Bash
args
{
  "command": "cat /tmp/claude-1002/-home-infatoshi-cuda-KernelBench-Hard/400239da-f68f-4aa1-8a16-bfbfbe931013/tasks/b6c9yuro1.output 2>/dev/null | head -50",
  "description": "Check benchmark progress"
}
in 1out 44cache_r 156861cache_w 885
tool
stdout (31 chars)
(Bash completed with no output)
assistant
TodoWrite
args
{
  "todos": [
    {
      "content": "Study FLA's chunk_kda Triton kernel and reference impl",
      "activeForm": "Studying FLA's chunk_kda Triton kernel and reference impl",
      "status": "completed"
    },
    {
      "content": "Check GPU state and torch/triton/cuda versions",
      "activeForm": "Checking GPU state and toolchain versions",
      "status": "completed"
    },
    {
      "content": "Implement chunk-parallel KDA forward in Triton (baseline working)",
      "activeForm": "Baseline KDA Triton kernel done",
      "status": "completed"
    },
    {
      "content": "Run check

... (805 more chars)
in 1out 68cache_r 157746cache_w 4848
tool
stdout (160 chars)
Todos have been modified successfully. Ensure that you continue to use the todo list to track your progress. Please proceed with the current tasks if applicable
assistant
TaskStop
args
{
  "task_id": "bpeclfxa4"
}
in 1out 41cache_r 162594cache_w 601
system — task_notification
↳ subagent complete
tool
stdout (539 chars)
message: 'Successfully stopped task: bpeclfxa4 (until ! pgrep -f "benchmark.py" > /dev/null 2>&1; do sleep 10; done; echo "BENCHMARK_DONE"; tail -100 /tmp/claude-1002/-home-infatoshi-cuda-KernelBench-Hard/400239da-f68f-4aa1-8a16-bfbfbe931013/tasks/b6c9yuro1.output)'
task_id: 'bpeclfxa4'
task_type: 'local_bash'
command: 'until ! pgrep -f "benchmark.py" > /dev/null 2>&1; do sleep 10; done; echo "BENCHMARK_DONE"; tail -100 /tmp/claude-1002/-home-infatoshi-cuda-KernelBench-Hard/400239da-f68f-4aa1-8a16-bfbfbe931013/tasks/b6c9yuro1.output'
assistant
ToolSearch
args
{
  "query": "select:TaskStop",
  "max_results": 1
}
in 1out 52cache_r 162594cache_w 1016
tool
stdout (0 chars)
assistant
Bash
args
{
  "command": "pkill -f benchmark.py 2>/dev/null; sleep 2; ps aux | grep -v grep | grep -E \"benchmark.py\" | head -3",
  "description": "Stop ongoing benchmark"
}
in 6out 5cache_r 163195cache_w 753
system — task_notification
↳ subagent complete
system — task_notification
↳ subagent complete
tool
stderr (13 chars)
Exit code 144