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submission 588910

josusanmartin · python · License unknown

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No package. Vendor the mirrored source: 231 lines, June 9 Researcher Reciprocity License v1.0.

submission_v727.py
curl "https://kernelindex.com/api/v1/implementations/kernelbot-amd-mixed-mla-588910?include=source"
interfacepython
Compatibility
measured onAMD Instinct MI355X
declared hardwareAMD Instinct MI355X
architecturesgfx950
dtypesbf16, int32

Benchmark evidence

1 measurement across 1 GPU, fastest first.

Operation / workload
Hardware
Latency
Rank
Observed
AMD Instinct MI355X
57.8µs
#222 of 766
2026-03-19

Reported · How evidence levels are derived →

Source and license

sourceavailable
revision digestsha256:c55e334d7387ea76fb04bfb80f67f3977f344a0eb03ae4d8d59087f2ae1d6363
license declaredunknown
license concludedunknown
authorsjosusanmartin
imported2026-08-15

Techniques

Extracted from the mirrored source by pattern, never inferred. Each row cites its line.

persistent-kerneldef _get_nonpersistent_cache(dev, bs, kvlen, split_override):

Kernel source

submission_v727.py231 lines
#!POPCORN leaderboard amd-mixed-mla
#!POPCORN gpu MI355X

"""V727: v722 with safer Q scale (0.20 instead of 0.14/0.15) for precision."""

import os

os.environ.setdefault("HIP_FORCE_DEV_KERNARG", "1")
os.environ.setdefault("AMD_DIRECT_DISPATCH", "1")

import torch
from task import input_t, output_t

import aiter
from aiter import dtypes as aiter_dtypes
from aiter import mla as aiter_mla

try:
    from aiter.jit.module_quant import static_per_tensor_quant as _static_per_tensor_quant
except Exception:
    from aiter.ops.quant import static_per_tensor_quant as _static_per_tensor_quant

try:
    from aiter.jit.module_mla_asm import mla_decode_stage1_asm_fwd as _mla_stage1
except Exception:
    _mla_stage1 = aiter.mla_decode_stage1_asm_fwd

try:
    from aiter.jit.module_mla_reduce import mla_reduce_v1 as _mla_reduce
except Exception:
    _mla_reduce = aiter.mla_reduce_v1

try:
    from aiter.jit.module_mla_metadata import get_mla_metadata_v1 as _get_mla_metadata_v1
except Exception:
    _get_mla_metadata_v1 = aiter.get_mla_metadata_v1

_get_mla_metadata_info_v1 = aiter.get_mla_metadata_info_v1
_mla_decode_fwd = aiter.mla.mla_decode_fwd

NUM_HEADS = 16
NUM_KV_HEADS = 1
QK_HEAD_DIM = 576
V_HEAD_DIM = 512
PAGE_SIZE = 1
SM_SCALE = float(1.0 / (QK_HEAD_DIM ** 0.5))

FP8_DTYPE = aiter_dtypes.fp8
BF16_DTYPE = torch.bfloat16
_FP8_FINFO = torch.finfo(FP8_DTYPE)
_Q020_SCALE = float(0.20 / _FP8_FINFO.max)
_Q014_SCALE = _Q020_SCALE  # Use safer 0.20 scale for all shapes
_Q015_SCALE = _Q020_SCALE

_scale_tensors = {}
_direct_cache = {}
_decode_cache = {}
_nonpersist_cache = {}

_SPLITBOOST_8K = {
    (32, 8192): 8,
    (64, 8192): 4,
    (256, 8192): 2,
}


def _get_scale(dev, scale):
    key = (dev.index or 0, scale)
    t = _scale_tensors.get(key)
    if t is None:
        t = torch.tensor([scale], dtype=torch.float32, device=dev)
        _scale_tensors[key] = t
    return t


def _resolve_num_splits(batch_size, kv_seq_len, dtype_kv, split_override):
    if split_override is not None:
        return int(split_override)
    num_splits, _ = aiter_mla.get_meta_param(None, batch_size, batch_size * kv_seq_len, NUM_HEADS, 1, dtype_kv)
    return int(num_splits)


def _quantize_q(out_fp8, q, q_scale):
    _static_per_tensor_quant(out_fp8, q, q_scale)


def _get_direct_cache(dev, qo_indptr, kv_indptr, bs, kvlen, dtype_q, dtype_kv, kv_gran, intra, causal, need_fp8):
    key = (dev.index or 0, bs, kvlen, dtype_q, dtype_kv, kv_gran, intra, causal, need_fp8)
    cached = _direct_cache.get(key)
    if cached is not None:
        return cached

    total_kv = bs * kvlen
    split_dtype = FP8_DTYPE if dtype_kv == FP8_DTYPE else BF16_DTYPE
    num_splits, _ = aiter_mla.get_meta_param(None, bs, total_kv, NUM_HEADS, 1, split_dtype)

    kv_indices = torch.arange(total_kv, dtype=torch.int32, device=dev)
    kv_lpl = torch.full((bs,), kvlen, dtype=torch.int32, device=dev)
    out = torch.empty((bs, NUM_HEADS, V_HEAD_DIM), dtype=BF16_DTYPE, device=dev)

    info = _get_mla_metadata_info_v1(bs, 1, NUM_HEADS, dtype_q, dtype_kv,
        is_sparse=False, fast_mode=True, num_kv_splits=num_splits, intra_batch_mode=intra)
    wmd, wi, wis, ri, rfm, rpm = [torch.empty(s, dtype=t, device=dev) for s, t in info]

    _get_mla_metadata_v1(qo_indptr, kv_indptr, kv_lpl, 16, 1, causal,
        wmd, wis, wi, ri, rfm, rpm,
        page_size=1, kv_granularity=kv_gran, max_seqlen_qo=1, uni_seqlen_qo=1,
        fast_mode=True, max_split_per_batch=num_splits, intra_batch_mode=intra,
        dtype_q=dtype_q, dtype_kv=dtype_kv)

    pt = int(rpm.numel())
    po = torch.empty((pt, 1, NUM_HEADS, V_HEAD_DIM), dtype=torch.float32, device=dev)
    pl = torch.empty((pt, 1, NUM_HEADS, 1), dtype=torch.float32, device=dev)
    q_fp8 = torch.empty((bs, NUM_HEADS, QK_HEAD_DIM), dtype=FP8_DTYPE, device=dev) if need_fp8 else None

    cached = (kv_indices, kv_lpl, out, wmd, wi, wis, ri, rfm, rpm, po, pl, q_fp8)
    _direct_cache[key] = cached
    return cached


def _get_decode_cache(dev, qo_indptr, kv_indptr, bs, kvlen, kv_gran, intra, split_override):
    key = (dev.index or 0, bs, kvlen, kv_gran, intra, split_override)
    cached = _decode_cache.get(key)
    if cached is not None:
        return cached

    num_splits = _resolve_num_splits(bs, kvlen, FP8_DTYPE, split_override)
    total_kv = bs * kvlen

    kv_indices = torch.arange(total_kv, dtype=torch.int32, device=dev)
    kv_lpl = torch.full((bs,), kvlen, dtype=torch.int32, device=dev)
    out = torch.empty((bs, NUM_HEADS, V_HEAD_DIM), dtype=BF16_DTYPE, device=dev)

    info = _get_mla_metadata_info_v1(bs, 1, NUM_HEADS, FP8_DTYPE, FP8_DTYPE,
        is_sparse=False, fast_mode=True, num_kv_splits=num_splits, intra_batch_mode=intra)
    wmd, wi, wis, ri, rfm, rpm = [torch.empty(s, dtype=t, device=dev) for s, t in info]

    _get_mla_metadata_v1(qo_indptr, kv_indptr, kv_lpl, 16, 1, False,
        wmd, wis, wi, ri, rfm, rpm,
        page_size=1, kv_granularity=kv_gran, max_seqlen_qo=1, uni_seqlen_qo=1,
        fast_mode=True, max_split_per_batch=num_splits, intra_batch_mode=intra,
        dtype_q=FP8_DTYPE, dtype_kv=FP8_DTYPE)

    q_fp8 = torch.empty((bs, NUM_HEADS, QK_HEAD_DIM), dtype=FP8_DTYPE, device=dev)
    cached = (kv_indices, kv_lpl, out, wmd, wi, wis, ri, rfm, rpm, num_splits, q_fp8)
    _decode_cache[key] = cached
    return cached


def _get_nonpersistent_cache(dev, bs, kvlen, split_override):
    key = (dev.index or 0, bs, kvlen, split_override)
    cached = _nonpersist_cache.get(key)
    if cached is not None:
        return cached

    total_kv = bs * kvlen
    num_splits, num_splits_indptr = aiter_mla.get_meta_param(split_override, bs, total_kv, NUM_HEADS, 1, FP8_DTYPE)
    kv_indices = torch.arange(total_kv, dtype=torch.int32, device=dev)
    kv_lpl = torch.full((bs,), kvlen, dtype=torch.int32, device=dev)
    out = torch.empty((bs, NUM_HEADS, V_HEAD_DIM), dtype=BF16_DTYPE, device=dev)
    logits = (
        out.view(bs, 1, NUM_HEADS, V_HEAD_DIM)
        if num_splits == 1
        else torch.empty((bs, num_splits, NUM_HEADS, V_HEAD_DIM), dtype=torch.float32, device=dev)
    )
    attn_lse = torch.empty((bs, num_splits, NUM_HEADS, 1), dtype=torch.float32, device=dev)
    q_fp8 = torch.empty((bs, NUM_HEADS, QK_HEAD_DIM), dtype=FP8_DTYPE, device=dev)

    cached = (num_splits, num_splits_indptr, kv_indices, kv_lpl, out, logits, attn_lse, q_fp8)
    _nonpersist_cache[key] = cached
    return cached


def custom_kernel(data: input_t) -> output_t:
    q, kv_data, qo_indptr, kv_indptr, config = data
    batch_size = int(config["batch_size"])
    kv_seq_len = int(config["kv_seq_len"])
    sm_scale = float(config["sm_scale"])

    if batch_size == 4 and kv_seq_len == 1024:
        c = _get_direct_cache(q.device, qo_indptr, kv_indptr, 4, 1024,
            BF16_DTYPE, BF16_DTYPE, 16, True, False, False)
        kv_buf = kv_data["bf16"].view(-1, 1, 1, QK_HEAD_DIM)
        _mla_stage1(
            q, kv_buf, qo_indptr, kv_indptr, c[0], c[1], None,
            c[3], c[4], c[5], 1, 1, 1, sm_scale, c[9], c[10], c[2], None, None)
        _mla_reduce(c[9], c[10], c[6], c[7], c[8], 1, c[2], None)
        return c[2]

    kv_fp8, kv_scale = kv_data["fp8"]
    kv_buf = kv_fp8.view(-1, 1, 1, QK_HEAD_DIM)
    dev = q.device

    if batch_size == 4 and kv_seq_len == 8192:
        c = _get_direct_cache(dev, qo_indptr, kv_indptr, 4, 8192,
            FP8_DTYPE, FP8_DTYPE, 64, True, False, True)
        q_scale = _get_scale(dev, _Q014_SCALE)
        _quantize_q(c[11], q, q_scale)
        _mla_stage1(
            c[11], kv_buf, qo_indptr, kv_indptr, c[0], c[1], None,
            c[3], c[4], c[5], 1, 1, 1, sm_scale, c[9], c[10], c[2], q_scale, kv_scale)
        _mla_reduce(c[9], c[10], c[6], c[7], c[8], 1, c[2], None)
        return c[2]

    if kv_seq_len == 1024:
        # ALL 1K shapes: persistent fp8 (safe — no non-persistent kernel)
        q_scale_val = _Q015_SCALE if batch_size == 256 else _Q014_SCALE
        c = _get_direct_cache(dev, qo_indptr, kv_indptr, batch_size, 1024,
            FP8_DTYPE, FP8_DTYPE, 8, True, False, True)
        q_scale = _get_scale(dev, q_scale_val)
        _quantize_q(c[11], q, q_scale)
        _mla_stage1(
            c[11], kv_buf, qo_indptr, kv_indptr, c[0], c[1], None,
            c[3], c[4], c[5], 1, 1, 1, sm_scale, c[9], c[10], c[2], q_scale, kv_scale)
        _mla_reduce(c[9], c[10], c[6], c[7], c[8], 1, c[2], None)
        return c[2]

    split_override = _SPLITBOOST_8K.get((batch_size, kv_seq_len))
    c = _get_decode_cache(dev, qo_indptr, kv_indptr, batch_size, 8192, 16, False, split_override)
    q_scale = _get_scale(dev, _Q014_SCALE)
    _quantize_q(c[10], q, q_scale)
    _mla_decode_fwd(
        c[10], kv_buf, c[2], qo_indptr, kv_indptr, c[0], c[1],
        1, 1, 1, sm_scale,
        num_kv_splits=c[9],
        work_meta_data=c[3], work_indptr=c[4], work_info_set=c[5],
        reduce_indptr=c[6], reduce_final_map=c[7], reduce_partial_map=c[8],
        q_scale=q_scale, kv_scale=kv_scale,
        intra_batch_mode=False)
    return c[2]
scrolls · 231 lines total

Source code from GPU Mode and the KernelBot dataset · June 9 Researcher Reciprocity License v1.0

Changes from previous submission

Against this author's previous submission submission 586726.

#!POPCORN leaderboard amd-mixed-mla
#!POPCORN gpu MI355X
- """v707 - bf16 for small shapes, 1-split for (64,1K)+(256,1K), persistent for 8K."""
+ """V727: v722 with safer Q scale (0.20 instead of 0.14/0.15) for precision."""
import os
⋯ 6 unchanged lines
import aiter
from aiter import dtypes as aiter_dtypes
from aiter import mla as aiter_mla
- from aiter import get_mla_metadata_info_v1, get_mla_metadata_v1
try:
- from aiter.jit.module_quant import static_per_tensor_quant
+ from aiter.jit.module_quant import static_per_tensor_quant as _static_per_tensor_quant
except Exception:
- try:
- from aiter.ops.quant import static_per_tensor_quant
- except Exception:
- static_per_tensor_quant = None
+ from aiter.ops.quant import static_per_tensor_quant as _static_per_tensor_quant
+ try:
+ from aiter.jit.module_mla_asm import mla_decode_stage1_asm_fwd as _mla_stage1
+ except Exception:
+ _mla_stage1 = aiter.mla_decode_stage1_asm_fwd
+
+ try:
+ from aiter.jit.module_mla_reduce import mla_reduce_v1 as _mla_reduce
+ except Exception:
+ _mla_reduce = aiter.mla_reduce_v1
+
+ try:
+ from aiter.jit.module_mla_metadata import get_mla_metadata_v1 as _get_mla_metadata_v1
+ except Exception:
+ _get_mla_metadata_v1 = aiter.get_mla_metadata_v1
+
+ _get_mla_metadata_info_v1 = aiter.get_mla_metadata_info_v1
+ _mla_decode_fwd = aiter.mla.mla_decode_fwd
+
NUM_HEADS = 16
+ NUM_KV_HEADS = 1
QK_HEAD_DIM = 576
V_HEAD_DIM = 512
+ PAGE_SIZE = 1
+ SM_SCALE = float(1.0 / (QK_HEAD_DIM ** 0.5))
FP8_DTYPE = aiter_dtypes.fp8
+ BF16_DTYPE = torch.bfloat16
_FP8_FINFO = torch.finfo(FP8_DTYPE)
+ _Q020_SCALE = float(0.20 / _FP8_FINFO.max)
+ _Q014_SCALE = _Q020_SCALE # Use safer 0.20 scale for all shapes
+ _Q015_SCALE = _Q020_SCALE
- _cache = {}
+ _scale_tensors = {}
+ _direct_cache = {}
+ _decode_cache = {}
+ _nonpersist_cache = {}
+ _SPLITBOOST_8K = {
+ (32, 8192): 8,
+ (64, 8192): 4,
+ (256, 8192): 2,
+ }
- def _quantize_q_fp8(q, q_fp8_buf):
- amax = q.abs().amax().clamp(min=1e-12)
- scale = (amax / _FP8_FINFO.max).reshape(1).to(torch.float32)
- if static_per_tensor_quant is not None:
- static_per_tensor_quant(q_fp8_buf, q, scale)
- else:
- q_fp8_buf.copy_(
- (q / scale).clamp(min=_FP8_FINFO.min, max=_FP8_FINFO.max).to(FP8_DTYPE)
- )
- return scale
+ def _get_scale(dev, scale):
+ key = (dev.index or 0, scale)
+ t = _scale_tensors.get(key)
+ if t is None:
+ t = torch.tensor([scale], dtype=torch.float32, device=dev)
+ _scale_tensors[key] = t
+ return t
- def _build_nonpersist_1split(dev, bs, kvlen, kv_indptr):
- """Non-persistent mode with 1 split: output written directly, no reduce needed."""
- total_kv = bs * kvlen
- _, num_splits_indptr = aiter_mla.get_meta_param(1, bs, total_kv, NUM_HEADS, 1, FP8_DTYPE)
- kv_indices = torch.arange(total_kv, dtype=torch.int32, device=dev)
- kv_lpl = torch.full((bs,), kvlen, dtype=torch.int32, device=dev)
- out = torch.empty((bs, NUM_HEADS, V_HEAD_DIM), dtype=torch.bfloat16, device=dev)
- # With 1 split, logits shares memory with out
- logits = out.view(bs, 1, NUM_HEADS, V_HEAD_DIM)
- attn_lse = torch.empty((bs, 1, NUM_HEADS, 1), dtype=torch.float32, device=dev)
- q_fp8 = torch.empty((bs, NUM_HEADS, QK_HEAD_DIM), dtype=FP8_DTYPE, device=dev)
- return (num_splits_indptr, kv_indices, kv_lpl, out, logits, attn_lse, q_fp8)
+ def _resolve_num_splits(batch_size, kv_seq_len, dtype_kv, split_override):
+ if split_override is not None:
+ return int(split_override)
+ num_splits, _ = aiter_mla.get_meta_param(None, batch_size, batch_size * kv_seq_len, NUM_HEADS, 1, dtype_kv)
+ return int(num_splits)
- def _build_persistent(dev, qo_indptr, kv_indptr, bs, kvlen, kv_gran, intra):
- """Persistent mode with metadata — uses mla_reduce_v1."""
+
+ def _quantize_q(out_fp8, q, q_scale):
+ _static_per_tensor_quant(out_fp8, q, q_scale)
+
+
+ def _get_direct_cache(dev, qo_indptr, kv_indptr, bs, kvlen, dtype_q, dtype_kv, kv_gran, intra, causal, need_fp8):
+ key = (dev.index or 0, bs, kvlen, dtype_q, dtype_kv, kv_gran, intra, causal, need_fp8)
+ cached = _direct_cache.get(key)
+ if cached is not None:
+ return cached
+
total_kv = bs * kvlen
- num_splits, _ = aiter_mla.get_meta_param(None, bs, total_kv, NUM_HEADS, 1, FP8_DTYPE)
+ split_dtype = FP8_DTYPE if dtype_kv == FP8_DTYPE else BF16_DTYPE
+ num_splits, _ = aiter_mla.get_meta_param(None, bs, total_kv, NUM_HEADS, 1, split_dtype)
+
kv_indices = torch.arange(total_kv, dtype=torch.int32, device=dev)
kv_lpl = torch.full((bs,), kvlen, dtype=torch.int32, device=dev)
- out = torch.empty((bs, NUM_HEADS, V_HEAD_DIM), dtype=torch.bfloat16, device=dev)
+ out = torch.empty((bs, NUM_HEADS, V_HEAD_DIM), dtype=BF16_DTYPE, device=dev)
- info = get_mla_metadata_info_v1(
- bs, 1, NUM_HEADS, FP8_DTYPE, FP8_DTYPE,
- is_sparse=False, fast_mode=True, num_kv_splits=num_splits, intra_batch_mode=intra,
- )
- bufs = [torch.empty(s, dtype=t, device=dev) for s, t in info]
- wmd, wi, wis, ri, rfm, rpm = bufs
- get_mla_metadata_v1(
- qo_indptr, kv_indptr, kv_lpl, 16, 1, False,
+ info = _get_mla_metadata_info_v1(bs, 1, NUM_HEADS, dtype_q, dtype_kv,
+ is_sparse=False, fast_mode=True, num_kv_splits=num_splits, intra_batch_mode=intra)
+ wmd, wi, wis, ri, rfm, rpm = [torch.empty(s, dtype=t, device=dev) for s, t in info]
+
+ _get_mla_metadata_v1(qo_indptr, kv_indptr, kv_lpl, 16, 1, causal,
wmd, wis, wi, ri, rfm, rpm,
page_size=1, kv_granularity=kv_gran, max_seqlen_qo=1, uni_seqlen_qo=1,
fast_mode=True, max_split_per_batch=num_splits, intra_batch_mode=intra,
- dtype_q=FP8_DTYPE, dtype_kv=FP8_DTYPE,
- )
+ dtype_q=dtype_q, dtype_kv=dtype_kv)
+
pt = int(rpm.numel())
po = torch.empty((pt, 1, NUM_HEADS, V_HEAD_DIM), dtype=torch.float32, device=dev)
pl = torch.empty((pt, 1, NUM_HEADS, 1), dtype=torch.float32, device=dev)
- q_fp8 = torch.empty((bs, NUM_HEADS, QK_HEAD_DIM), dtype=FP8_DTYPE, device=dev)
- return (kv_indices, kv_lpl, out, wmd, wi, wis, ri, rfm, rpm, po, pl, q_fp8)
+ q_fp8 = torch.empty((bs, NUM_HEADS, QK_HEAD_DIM), dtype=FP8_DTYPE, device=dev) if need_fp8 else None
+ cached = (kv_indices, kv_lpl, out, wmd, wi, wis, ri, rfm, rpm, po, pl, q_fp8)
+ _direct_cache[key] = cached
+ return cached
- def _build_bf16_persistent(dev, qo_indptr, kv_indptr, bs, kvlen, kv_gran, intra):
- """Persistent mode with bf16 Q + bf16 KV — no quantization needed."""
+
+ def _get_decode_cache(dev, qo_indptr, kv_indptr, bs, kvlen, kv_gran, intra, split_override):
+ key = (dev.index or 0, bs, kvlen, kv_gran, intra, split_override)
+ cached = _decode_cache.get(key)
+ if cached is not None:
+ return cached
+
+ num_splits = _resolve_num_splits(bs, kvlen, FP8_DTYPE, split_override)
total_kv = bs * kvlen
- num_splits, _ = aiter_mla.get_meta_param(None, bs, total_kv, NUM_HEADS, 1, torch.bfloat16)
+
kv_indices = torch.arange(total_kv, dtype=torch.int32, device=dev)
kv_lpl = torch.full((bs,), kvlen, dtype=torch.int32, device=dev)
- out = torch.empty((bs, NUM_HEADS, V_HEAD_DIM), dtype=torch.bfloat16, device=dev)
+ out = torch.empty((bs, NUM_HEADS, V_HEAD_DIM), dtype=BF16_DTYPE, device=dev)
- info = get_mla_metadata_info_v1(
- bs, 1, NUM_HEADS, torch.bfloat16, torch.bfloat16,
- is_sparse=False, fast_mode=True, num_kv_splits=num_splits, intra_batch_mode=intra,
- )
- bufs = [torch.empty(s, dtype=t, device=dev) for s, t in info]
- wmd, wi, wis, ri, rfm, rpm = bufs
- get_mla_metadata_v1(
- qo_indptr, kv_indptr, kv_lpl, 16, 1, False,
+ info = _get_mla_metadata_info_v1(bs, 1, NUM_HEADS, FP8_DTYPE, FP8_DTYPE,
+ is_sparse=False, fast_mode=True, num_kv_splits=num_splits, intra_batch_mode=intra)
+ wmd, wi, wis, ri, rfm, rpm = [torch.empty(s, dtype=t, device=dev) for s, t in info]
+
+ _get_mla_metadata_v1(qo_indptr, kv_indptr, kv_lpl, 16, 1, False,
wmd, wis, wi, ri, rfm, rpm,
page_size=1, kv_granularity=kv_gran, max_seqlen_qo=1, uni_seqlen_qo=1,
fast_mode=True, max_split_per_batch=num_splits, intra_batch_mode=intra,
- dtype_q=torch.bfloat16, dtype_kv=torch.bfloat16,
+ dtype_q=FP8_DTYPE, dtype_kv=FP8_DTYPE)
+
+ q_fp8 = torch.empty((bs, NUM_HEADS, QK_HEAD_DIM), dtype=FP8_DTYPE, device=dev)
+ cached = (kv_indices, kv_lpl, out, wmd, wi, wis, ri, rfm, rpm, num_splits, q_fp8)
+ _decode_cache[key] = cached
+ return cached
+
+
+ def _get_nonpersistent_cache(dev, bs, kvlen, split_override):
+ key = (dev.index or 0, bs, kvlen, split_override)
+ cached = _nonpersist_cache.get(key)
+ if cached is not None:
+ return cached
+
+ total_kv = bs * kvlen
+ num_splits, num_splits_indptr = aiter_mla.get_meta_param(split_override, bs, total_kv, NUM_HEADS, 1, FP8_DTYPE)
+ kv_indices = torch.arange(total_kv, dtype=torch.int32, device=dev)
+ kv_lpl = torch.full((bs,), kvlen, dtype=torch.int32, device=dev)
+ out = torch.empty((bs, NUM_HEADS, V_HEAD_DIM), dtype=BF16_DTYPE, device=dev)
+ logits = (
+ out.view(bs, 1, NUM_HEADS, V_HEAD_DIM)
+ if num_splits == 1
+ else torch.empty((bs, num_splits, NUM_HEADS, V_HEAD_DIM), dtype=torch.float32, device=dev)
)
- pt = int(rpm.numel())
- po = torch.empty((pt, 1, NUM_HEADS, V_HEAD_DIM), dtype=torch.float32, device=dev)
- pl = torch.empty((pt, 1, NUM_HEADS, 1), dtype=torch.float32, device=dev)
- return (kv_indices, kv_lpl, out, wmd, wi, wis, ri, rfm, rpm, po, pl)
+ attn_lse = torch.empty((bs, num_splits, NUM_HEADS, 1), dtype=torch.float32, device=dev)
+ q_fp8 = torch.empty((bs, NUM_HEADS, QK_HEAD_DIM), dtype=FP8_DTYPE, device=dev)
+ cached = (num_splits, num_splits_indptr, kv_indices, kv_lpl, out, logits, attn_lse, q_fp8)
+ _nonpersist_cache[key] = cached
+ return cached
+
def custom_kernel(data: input_t) -> output_t:
q, kv_data, qo_indptr, kv_indptr, config = data
- bs = int(config["batch_size"])
- kvlen = int(config["kv_seq_len"])
+ batch_size = int(config["batch_size"])
+ kv_seq_len = int(config["kv_seq_len"])
sm_scale = float(config["sm_scale"])
- dev = q.device
+ if batch_size == 4 and kv_seq_len == 1024:
+ c = _get_direct_cache(q.device, qo_indptr, kv_indptr, 4, 1024,
+ BF16_DTYPE, BF16_DTYPE, 16, True, False, False)
+ kv_buf = kv_data["bf16"].view(-1, 1, 1, QK_HEAD_DIM)
+ _mla_stage1(
+ q, kv_buf, qo_indptr, kv_indptr, c[0], c[1], None,
+ c[3], c[4], c[5], 1, 1, 1, sm_scale, c[9], c[10], c[2], None, None)
+ _mla_reduce(c[9], c[10], c[6], c[7], c[8], 1, c[2], None)
+ return c[2]
+
kv_fp8, kv_scale = kv_data["fp8"]
kv_buf = kv_fp8.view(-1, 1, 1, QK_HEAD_DIM)
+ dev = q.device
- key = (dev.index, bs, kvlen)
-
- # --- bf16 path for small batches: skip Q quantization entirely ---
- if bs <= 32 and kvlen == 1024:
- bkey = ("bf16", *key)
- if bkey not in _cache:
- _cache[bkey] = _build_bf16_persistent(dev, qo_indptr, kv_indptr, bs, kvlen, 16, True)
- c = _cache[bkey]
- kv_bf16 = kv_data["bf16"].view(-1, 1, 1, QK_HEAD_DIM)
- aiter.mla_decode_stage1_asm_fwd(
- q, kv_bf16, qo_indptr, kv_indptr, c[0], c[1], None,
- c[3], c[4], c[5], 1, 1, 1, sm_scale, c[9], c[10], c[2], None, None,
- )
- aiter.mla_reduce_v1(c[9], c[10], c[6], c[7], c[8], 1, c[2], None)
+ if batch_size == 4 and kv_seq_len == 8192:
+ c = _get_direct_cache(dev, qo_indptr, kv_indptr, 4, 8192,
+ FP8_DTYPE, FP8_DTYPE, 64, True, False, True)
+ q_scale = _get_scale(dev, _Q014_SCALE)
+ _quantize_q(c[11], q, q_scale)
+ _mla_stage1(
+ c[11], kv_buf, qo_indptr, kv_indptr, c[0], c[1], None,
+ c[3], c[4], c[5], 1, 1, 1, sm_scale, c[9], c[10], c[2], q_scale, kv_scale)
+ _mla_reduce(c[9], c[10], c[6], c[7], c[8], 1, c[2], None)
return c[2]
- if bs == 4 and kvlen == 8192:
- bkey = ("bf16", *key)
- if bkey not in _cache:
- _cache[bkey] = _build_bf16_persistent(dev, qo_indptr, kv_indptr, bs, kvlen, 64, True)
- c = _cache[bkey]
- kv_bf16 = kv_data["bf16"].view(-1, 1, 1, QK_HEAD_DIM)
- aiter.mla_decode_stage1_asm_fwd(
- q, kv_bf16, qo_indptr, kv_indptr, c[0], c[1], None,
- c[3], c[4], c[5], 1, 1, 1, sm_scale, c[9], c[10], c[2], None, None,
- )
- aiter.mla_reduce_v1(c[9], c[10], c[6], c[7], c[8], 1, c[2], None)
+ if kv_seq_len == 1024:
+ # ALL 1K shapes: persistent fp8 (safe — no non-persistent kernel)
+ q_scale_val = _Q015_SCALE if batch_size == 256 else _Q014_SCALE
+ c = _get_direct_cache(dev, qo_indptr, kv_indptr, batch_size, 1024,
+ FP8_DTYPE, FP8_DTYPE, 8, True, False, True)
+ q_scale = _get_scale(dev, q_scale_val)
+ _quantize_q(c[11], q, q_scale)
+ _mla_stage1(
+ c[11], kv_buf, qo_indptr, kv_indptr, c[0], c[1], None,
+ c[3], c[4], c[5], 1, 1, 1, sm_scale, c[9], c[10], c[2], q_scale, kv_scale)
+ _mla_reduce(c[9], c[10], c[6], c[7], c[8], 1, c[2], None)
return c[2]
- # --- 1-split non-persistent for select shapes: skip reduce ---
- if (bs, kvlen) in ((64, 1024), (256, 1024)):
- nkey = ("np1", *key)
- if nkey not in _cache:
- _cache[nkey] = _build_nonpersist_1split(dev, bs, kvlen, kv_indptr)
- c = _cache[nkey]
- q_scale = _quantize_q_fp8(q, c[6])
- aiter.mla_decode_stage1_asm_fwd(
- c[6], kv_buf, qo_indptr, kv_indptr, c[1], c[2], c[0],
- None, None, None, 1, 1, 1, sm_scale, c[4], c[5], c[3], q_scale, kv_scale,
- )
- return c[3]
-
- # --- Persistent mode for remaining shapes ---
- pkey = ("persist", *key)
- if pkey not in _cache:
- kv_gran = 64 if kvlen == 8192 else 8
- intra = True
- _cache[pkey] = _build_persistent(dev, qo_indptr, kv_indptr, bs, kvlen, kv_gran, intra)
- c = _cache[pkey]
- q_scale = _quantize_q_fp8(q, c[11])
- aiter.mla_decode_stage1_asm_fwd(
- c[11], kv_buf, qo_indptr, kv_indptr, c[0], c[1], None,
- c[3], c[4], c[5], 1, 1, 1, sm_scale, c[9], c[10], c[2], q_scale, kv_scale,
- )
- aiter.mla_reduce_v1(c[9], c[10], c[6], c[7], c[8], 1, c[2], None)
+ split_override = _SPLITBOOST_8K.get((batch_size, kv_seq_len))
+ c = _get_decode_cache(dev, qo_indptr, kv_indptr, batch_size, 8192, 16, False, split_override)
+ q_scale = _get_scale(dev, _Q014_SCALE)
+ _quantize_q(c[10], q, q_scale)
+ _mla_decode_fwd(
+ c[10], kv_buf, c[2], qo_indptr, kv_indptr, c[0], c[1],
+ 1, 1, 1, sm_scale,
+ num_kv_splits=c[9],
+ work_meta_data=c[3], work_indptr=c[4], work_info_set=c[5],
+ reduce_indptr=c[6], reduce_final_map=c[7], reduce_partial_map=c[8],
+ q_scale=q_scale, kv_scale=kv_scale,
+ intra_batch_mode=False)
return c[2]
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