Files
project_6/ex_engine/xllm_layers/npu_torch/attention.h
project6-dev f28223c9da perf: native ixformer decode (v1 ≤32K, v2 >32K) + flash_attn_varlen prefill
Replaces all Python PyTorch fallback attention with native ixformer kernels:

Decode path:
- ≤32K: paged_attention_v1 (5D KV layout, x=8) — verified on real BI-V100
- >32K: paged_attention_v2 (5D→4D permute) — verified 65K+ on real BI-V100
- Removes _forward_decode_pytorch Python fallback entirely

Prefill path (profiling):
- _run_sdpa_fallback now uses ixformer.flash_attn_varlen_func
- head_dim=256 verified correct (diff<0.004) and 1.7x faster than PyTorch
- Falls back to Q-tiling pure-math if ixformer unavailable

Also includes: MoE kernel integration, GDN C++ kernels, diagnostic scripts,
xllm upstream layer/kernel references, .dockerignore cleanup.

All changes verified on real BI-V100 hardware (single card).
2026-08-13 07:04:21 +00:00

71 lines
2.2 KiB
C++

/* Copyright 2025 The xLLM Authors. All Rights Reserved.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
https://github.com/jd-opensource/xllm/blob/main/LICENSE
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
==============================================================================*/
#pragma once
#include <torch/torch.h>
#include <tuple>
#include "framework/kv_cache/kv_cache.h"
#include "framework/model/model_input_params.h"
#include "layers/common/attention_metadata.h"
namespace xllm {
namespace layer {
class AttentionImpl : public torch::nn::Module {
public:
AttentionImpl() = default;
AttentionImpl(int64_t num_heads,
int64_t head_size,
float scale,
int64_t num_kv_heads,
int64_t sliding_window);
std::tuple<torch::Tensor, std::optional<torch::Tensor>> forward(
const AttentionMetadata& attn_metadata,
torch::Tensor& query,
torch::Tensor& key,
torch::Tensor& value,
KVCache& kv_cache);
void prefill_forward(torch::Tensor& query,
torch::Tensor& key,
torch::Tensor& value,
torch::Tensor& output,
const torch::Tensor& k_cache,
const std::optional<torch::Tensor>& v_cache,
const AttentionMetadata& attn_metadata);
void decoder_forward(torch::Tensor& query,
torch::Tensor& output,
const torch::Tensor& k_cache,
const std::optional<torch::Tensor>& v_cache,
const AttentionMetadata& attn_metadata);
private:
int64_t num_heads_;
int64_t head_size_;
float scale_;
int64_t num_kv_heads_;
int64_t sliding_window_;
};
TORCH_MODULE(Attention);
} // namespace layer
} // namespace xllm