docs: fix stale developer documentation claims

- Move task_alloc/task_free/task_extend/task_cached/task_record_hashes and bind from the PagePool card to a new TaskCacheManager card matching pool.py
- Drop the nonexistent Executor tokenizer attribute and association, add task_cache instead
- Add AllocationStrategy/ContiguousStrategy/PagedStrategy cards and point Allocator/RadixCache composition at PagedStrategy
- Add TaskCacheManager and the allocation strategies to the module overview, add _task_cache to InferenceScheduler
- Fix the design-pattern count in the table of contents (15 -> 16)
- Rewrite the FlashAttnBackend class docstring: packed decode gathers flat K/V via req_to_token and calls flash_attn_varlen_func; dense prefill uses flash_attn_func (no flash_attn_with_kvcache exists)
- Apply the same correction to the backend bullets in internals.md and cuda_kernels.md
- Rename the stale fp8_mma_test.cu reference to fp8_test.cu in cuda_kernels.md
This commit is contained in:
2026-08-31 14:24:51 +08:00
parent a7d4cb25c5
commit e3c3e28a11
4 changed files with 51 additions and 19 deletions
+6 -5
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@@ -694,12 +694,13 @@ class CudaBackend(AttentionBackend):
class FlashAttnBackend(AttentionBackend):
"""FlashAttention backend via the optional ``flash-attn`` package.
Decode (q_len=1, contiguous cache): uses ``flash_attn_with_kvcache``,
which reads K/V directly from the flat pool via cache_batch_idx +
cache_seqlens — no materialized KV gather.
Decode (q_len=1, contiguous cache): writes K/V to the pool, gathers
flat K/V via the ``req_to_token`` page table, and calls
``flash_attn_varlen_func`` over the ragged batch
(``qo_indptr``/``kv_indptr``).
Prefill / non-contiguous decode: falls back to KV gather +
``flash_attn_func``.
Prefill: packed 3-D calls share the ``flash_attn_varlen_func`` path;
dense 4-D calls go through ``flash_attn_func`` (mask-free only).
"""
@classmethod
+41 -10
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@@ -4,7 +4,7 @@
- [Class Diagram](#class-diagram) — Full Mermaid class diagram across 10+ namespaces
- [Module Overview](#module-overview) — Component inventory per module
- [Design Patterns](#design-patterns) — 15 documented patterns with classes
- [Design Patterns](#design-patterns) — 16 documented patterns with classes
- [Core Relationships](#core-relationships) — 11 key inter-component relationships
## Class Diagram
@@ -816,8 +816,8 @@ classDiagram
class Executor {
+AutoModel model
+AutoTokenizer tokenizer
+PagePool kv_cache
+TaskCacheManager task_cache
+InferenceWorkspace _workspace
+Optional[str] device
+Optional[torch.dtype] dtype
@@ -845,6 +845,7 @@ classDiagram
class InferenceScheduler {
+PagePool _cache
+TaskCacheManager _task_cache
+Executor _executor
+TaskManager _task_mgr
+Event _stop_event
@@ -888,6 +889,24 @@ classDiagram
+release(pages)
}
class AllocationStrategy {
<<abstract>>
+alloc(state, prompt_ids) bool
+free(state)
+extend(state, pos) bool
+write_indices(state, prompt_ids)
+record_hashes(state, prompt_ids, start_logical_page)
}
class ContiguousStrategy {
+write_indices(state, prompt_ids)
}
class PagedStrategy {
-Allocator _alloc
-RadixCache _prefix
}
class KVStorage {
+int size
+Tensor k_buffer
@@ -926,14 +945,21 @@ classDiagram
+bool contiguous
-KVStorage _storage
-ReqToTokenPool _req_pool
-Allocator _alloc
-RadixCache _prefix
-AllocationStrategy _strategy
+strategy AllocationStrategy
+req_pool ReqToTokenPool
+bind_tasks(req_indices, seq_lens, workspace, device, start_pos, incremental) KVCache
}
class TaskCacheManager {
-PagePool _pool
-Dict _states
+task_alloc(task_id, prompt_ids) bool
+task_free(task_id)
+task_extend(task_id, pos) bool
+task_cached(task_id) int
+task_record_hashes(task_id, prompt_ids, start_logical_page)
+bind_tasks(task_ids, workspace, device, start_pos) KVCache
+bind(task_ids, workspace) KVCache
}
class Task {
@@ -1316,17 +1342,22 @@ classDiagram
PositionIdStrategy <|-- DocResetPositionId
PositionIdStrategy <|-- ContinuousPositionId
StoreWriter <|-- BinWriter
AllocationStrategy <|-- ContiguousStrategy
AllocationStrategy <|-- PagedStrategy
RawRollout <|-- RolloutResult
LaunchStrategy <|-- TorchrunStrategy
LaunchStrategy <|-- LocalStrategy
%% --- Composition (strong ownership, part destroyed with whole) ---
PagePool *-- KVStorage
PagePool *-- ReqToTokenPool
PagePool *-- Allocator
PagePool *-- RadixCache
PagePool *-- AllocationStrategy
PagedStrategy *-- Allocator
PagedStrategy *-- RadixCache
TaskCacheManager o-- PagePool
RadixCache *-- RadixNode
InferenceEngine *-- InferenceScheduler
InferenceScheduler *-- PagePool
InferenceScheduler *-- TaskCacheManager
InferenceScheduler *-- Executor
Executor *-- InferenceWorkspace
InferenceScheduler *-- TaskManager
@@ -1419,7 +1450,7 @@ classDiagram
Task --> TaskStatus
InferenceEngine --> AutoModel
Executor --> AutoModel
Executor --> AutoTokenizer
Executor --> TaskCacheManager
TaskManager --> AutoTokenizer
```
@@ -1436,7 +1467,7 @@ classDiagram
| **astrai.model** | ModelFactory, AutoModel, AutoRegressiveLM, EmbeddingEncoder, DecoderBlock, GQA, MLA, MLP, DeepSeekMoE, AttnFactory, FFNFactory, RMSNorm, Linear, LoRAConfig, LoRALinear, RotaryEmbedding, Embedding | Neural network model |
| **astrai.tokenize** | AutoTokenizer, ChatTemplate | Tokenizer and chat template |
| **astrai.trainer** | Trainer, TrainContext, TrainContextBuilder, BaseStrategyGRPOStrategy, StrategyFactory, BaseSchedulerWSDScheduler, SchedulerFactory, TrainCallback(Protocol)MetricCallback, CallbackFactory, RawRollout, RolloutResult, BaseRewardModel, RolloutGenerator, RolloutRunner | Training workflow |
| **astrai.inference** | InferenceEngine, InferenceScheduler, Executor, InferenceWorkspace, PagePool, KVStorage, ReqToTokenPool, KVCache, Allocator, RadixCache, Task, TaskManager, TaskStatus, StreamDecoder, GenerateResult, BaseSamplingStrategySamplingPipeline, FrequencyPenaltyStrategy, ProtocolHandler, ResponseBuilder, OpenAIResponseBuilder, AnthropicResponseBuilder, StopChecker, GenContext, StopInfo, ChatMessage, FunctionDef, ToolDef, ChatCompletionRequest, AnthropicMessage, MessagesRequest, BaseToolParser, ToolParserFactory, SimpleJsonToolParser | Inference service |
| **astrai.inference** | InferenceEngine, InferenceScheduler, Executor, InferenceWorkspace, PagePool, TaskCacheManager, KVStorage, ReqToTokenPool, KVCache, Allocator, RadixCache, AllocationStrategy, ContiguousStrategy, PagedStrategy, Task, TaskManager, TaskStatus, StreamDecoder, GenerateResult, BaseSamplingStrategySamplingPipeline, FrequencyPenaltyStrategy, ProtocolHandler, ResponseBuilder, OpenAIResponseBuilder, AnthropicResponseBuilder, StopChecker, GenContext, StopInfo, ChatMessage, FunctionDef, ToolDef, ChatCompletionRequest, AnthropicMessage, MessagesRequest, BaseToolParser, ToolParserFactory, SimpleJsonToolParser | Inference service |
| **astrai.extension** | `backend` policy package, `ops` kernel-wrapper package, `fp8.py` FP8 strategy layer, AttentionBackend, TorchNativeBackend, CudaBackend, FlashAttnBackend, attention, attn_backend, ATTN_BACKEND, apply_rotary_emb, is_available | Stable API over attention/rotary/FP8 execution policy and optional CUDA kernels |
| **astrai.optim** | OptimizerFactory, MuonAdamW, NoraNadamW, ManoAdamW, composite_step/composite_zero_grad/composite_state_dict, partition_optimizer_parameters | Built-in optimizers (`muon_adamw` / `nora_nadamw` / `mano_adamw`) with shared composite-optimizer helpers |
| **astrai.parallel** | spawn_parallel_fn, setup_parallel, get_rank/get_world_size/get_current_device, only_on_rank, LaunchStrategy, TorchrunStrategy, LocalStrategy, BaseExecutor, ExecutorFactory, NoneExecutor, DDPExecutor, FSDPExecutor, GradientState, AccumOptimizer, AccumScheduler | Distributed parallel & gradient accumulation |
@@ -1478,4 +1509,4 @@ classDiagram
10. **AutoModel**: `from_pretrained()` loads `config.json` + `model.safetensors`, `_disable_random_init` replaces `nn.init.*` with no-ops
11. **Protocols**: `OptimizerProtocol` / `SchedulerProtocol` — structural subtyping for `AccumOptimizer` / `AccumScheduler` wrappers
> Document Update Time: 2026-08-22
> Document Update Time: 2026-08-29
+3 -3
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@@ -305,7 +305,7 @@ cycle belong under `TYPE_CHECKING`.
- **`AttentionBackend`** (ABC): `fwd_decode` / `fwd_prefill` abstract methods, `forward` dispatches by q_len
- **`CudaBackend`**: CUDA kernel dispatch — decode via `attn_paged_decode` (page_size=1), prefill via `attn_paged_prefill` (ragged batch, `qo_indptr` + `kv_indptr`). Default on GPU.
- **`FlashAttnBackend`**: Optional flash-attn dispatch with `flash_attn_with_kvcache` fast path.
- **`FlashAttnBackend`**: Optional flash-attn dispatch via `flash_attn_varlen_func` over gathered flat K/V.
- **`TorchNativeBackend`**: SDPA with indirect KV cache gather (always-available fallback)
Default priority: cuda > flash > torch. Set ``ASTR_BACKEND=cuda|torch_native|flash``
@@ -415,7 +415,7 @@ nvcc -I csrc -arch=sm_89 -O3 --use_fast_math \
Test files:
- `attn_test.cu` — decode + prefill kernels (correctness tables + benchmarks)
- `attn_paged_test.cu` — paged decode/prefill kernels
- `fp8_mma_test.cu` — BF16→FP8→BF16 MMA demo (sm_89)
- `fp8_test.cu` — single-warp bf16→fp8→mma.sync sanity check + full FP8 GEMM correctness (sm_89)
## Benchmarks
@@ -482,4 +482,4 @@ csrc/
Compiled `.so` files are placed in `astrai/extension/lib/`, separate from Python source files.
> Document Update Time: 2026-08-22
> Document Update Time: 2026-08-29
+1 -1
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@@ -185,7 +185,7 @@ The extension package separates mechanism from policy:
Attention computation is decoupled from the model via `AttentionBackend` ABC (`astrai/extension/backend/attention.py`):
- **`CudaBackend`** (default when supported): decode path uses `attn_paged_decode` with `page_size=1` (the `req_to_token` table serves as the page table, each token slot is a single-token "page"); prefill path uses the ragged-batch `attn_paged_prefill` (addresses each request via `qo_indptr` + `kv_indptr` directly against the flat pool).
- **`FlashAttnBackend`**: optional flash-attn dispatch with `flash_attn_with_kvcache` fast path for contiguous cache; falls back to KV gather + `flash_attn_func`.
- **`FlashAttnBackend`**: optional flash-attn dispatch; inference paths gather flat K/V from the pool via `req_to_token` and call `flash_attn_varlen_func` over the ragged batch (fp16/bf16 only); dense mask-free training calls use `flash_attn_func`.
- **`TorchNativeBackend`** (always-available fallback): writes K/V to cache, gathers via `req_to_token` indirect indexing, calls `F.scaled_dot_product_attention`.
- The `attention(...)` entry point uses cuda > flash > torch priority and chooses another compatible backend when an automatically selected backend cannot handle a call.
- Resolution precedence is: explicit `attn_backend(...)` context > `ASTR_BACKEND` env > default. An explicit `attn_backend(...)` selection is strict (incompatible calls raise); `ASTR_BACKEND` is a default-level override that falls back to a compatible backend when incapable. Training calls (`fwd=None`, no KV cache) resolve by capability: the CUDA cache kernels cannot run without a cache, so they fall back to flash (mask-free/causal calls only) and finally to torch SDPA.