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Add: schedule A5 HBG Mix tasks through SSBUF - #2472

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zhusy54:feat/a5-hbg-ssbuf-mix
Sep 30, 2026
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ChaoZheng109 merged 1 commit into
hw-native-sys:mainfrom
zhusy54:feat/a5-hbg-ssbuf-mix

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@zhusy54 zhusy54 commented Sep 29, 2026 •

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Summary

  • Schedule A5 HBG Mix tasks through SSBUF with per-lane payload publication and completion; release dependencies only after all active subtasks finish.
  • Preserve ordinary AIC/AIV refill behavior. A newly resolved Mix task may use direct refill when the ready-queue snapshot is empty and all required lane slots and a tracker are available. Attempt it before claiming the shared Mix queue; otherwise enqueue it, then try the queue.
  • Track Mix tasks independently of gang tasks, remove unused materialization and local ready-scan parameters, and initialize worker payloads in the worker setup loop.
  • Index the existing profiling trace by executable subtask, batch trace invalidations, and publish trace validity with st_dev.
  • Cover Mix chain, burst, interleaved, rendezvous, direct refill, and queue fallback behavior with scene and scheduler tests.

Validation

  • Rebased onto current main and rebuilt the editable runtime.
  • A5 HBG scheduler contracts, dispatch, ready, and bind-ledger C++ tests: 153 passed across 4 targets.
  • A5 onboard after rebase: single-block Mix and Mix/SPMD graph execution: 3 passed.
  • Pre-commit checks passed.
  • Earlier revision: Python swimlane and capture-builder tests: 112 passed. Mix chain, interleaved, and rendezvous onboard cases passed.
  • A5 simulation could not run in this environment because g++-15 is unavailable.

Performance note

A pre-cleanup A/B measurement of the scheduler optimizations showed no Mix chain speedup: unprofiled device wall time changed from 304.15 to 310.35 µs for mask6 and from 366.75 to 369.55 µs for mask7. The final revision has not been rebenchmarked, so these figures should not be treated as its performance result.

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Review in Change Stack →

Navigate logical layers of code changes, visualize relationships, and explore their blast radius.

📝 Walkthrough

Walkthrough

The resident A5 scheduler now supports single-block Mix tasks across participating lanes. It adds lane admission, dispatch publication, aggregated completion and refill, and per-subtask trace profiling. New tests cover mixed-kernel execution and rendezvous cases. Design documents record scheduling contracts and measurements.

Changes

Resident A5 Mix scheduling

Layer / File(s) Summary
Scheduler contracts and task metadata
src/a5/runtime/host_build_graph/runtime/scheduler/scheduler_types.h, scheduler_graph.h, scheduler_ready.h, scheduler_ssbuf.h, src/a5/runtime/host_build_graph/host/runtime_maker.cpp, src/a5/runtime/host_build_graph/runtime/dispatch_payload.h, src/a5/runtime/host_build_graph/common/intrinsic.h, tests/ut/cpp/a5/runtime/host_build_graph/hbg_scheduler_test_support.h, test_hbg_scheduler_contracts.cpp, src/a5/runtime/host_build_graph/docs/RUNTIME_LOGIC.md
The scheduler adds a third ready queue for Mix tasks, trace-index metadata, and support for parsing and sharing task arguments. Resident task-shape validation accepts one to three active subtasks while retaining the single-block and no-sync-start conditions.
Mix admission and lane dispatch
src/a5/runtime/host_build_graph/runtime/scheduler/scheduler_ready.h, scheduler_graph.h, scheduler_mix.h, src/a5/runtime/host_build_graph/aicore/aicore_executor.cpp, src/a5/runtime/host_build_graph/common/intrinsic.h, tests/st/a5/host_build_graph/single_block_mix/*, tests/ut/cpp/a5/runtime/host_build_graph/test_hbg_scheduler_dispatch.cpp, test_hbg_scheduler_ready.cpp, tests/ut/cpp/common/host_build_graph/test_hbg_bind_ledger.cpp, src/a5/runtime/host_build_graph/docs/RUNTIME_LOGIC.md, docs/zh-cn/a5-hbg-ssbuf-mix.md
The scheduler plans compatible free slots and a tracker before claiming Mix work. It prepares all participating lane payloads before publication, assigns per-lane dispatch sequences, and uses the final physical AIV placement for sub-block context. Tests add mixed-kernel orchestration, rendezvous kernels, and dispatch and admission cases.
Completion aggregation and refill
src/a5/runtime/host_build_graph/runtime/scheduler/scheduler_completion.h, scheduler_ready.h, scheduler_dispatch.h, src/a5/runtime/host_build_graph/aicore/aicore_executor.cpp, docs/zh-cn/a5-hbg-ssbuf-mix.md, src/a5/runtime/host_build_graph/docs/RUNTIME_LOGIC.md, tests/ut/cpp/a5/runtime/host_build_graph/test_hbg_scheduler_dispatch.cpp
Completion frees each finished lane slot and resolves a Mix task after all active subtasks finish. The scheduler handles Mix candidates, ordinary refill, and deferred work according to available capacity. Tests cover partial and final completion, candidate ordering, and deferred stealing.
Trace profiling and verification records
src/common/host_build_graph/sched_phase_kind.h, src/a5/runtime/host_build_graph/host/runtime_maker.cpp, aicore/aicore_executor.cpp, aicpu/aicpu_executor.cpp, simpler_setup/tools/hbg/phases.py, simpler_setup/tools/swimlane_converter.py, docs/investigations/*, docs/investigations/README.md, docs/design/a5-hbg-ssbuf-mix.md, docs/zh-cn/a5-hbg-ssbuf-mix.md, tests/ut/cpp/a5/runtime/host_build_graph/test_hbg_scheduler_dispatch.cpp
Trace storage and timing records use executable-subtask indices. New phase kinds cover executor trace writes, completion trace reads, resolve work, and direct preparation. The swimlane converter associates executor trace events with task worker lanes. The investigation reports that forced inlining did not improve ordinary AIC chain latency; the design document records implementation contracts and measurements.

Priority: ⬇️ Low

Estimated code review effort: 4 (Complex) | ~60 minutes

Change: Feature

Sequence Diagram(s)

sequenceDiagram
  participant Ready as scheduler_claim_ready_for_slot
  participant Mix as scheduler_dispatch_mix_ready
  participant Prepare as scheduler_prepare_dispatch_slot
  participant Commit as scheduler_commit_dispatch_slot
  participant Executor as AICore Executor
  Ready->>Mix: claim task and plan lane placement
  Mix->>Prepare: prepare participating lane payloads
  Prepare-->>Mix: prepared payloads
  Mix->>Commit: stage lanes and commit publication
  Commit-->>Executor: publish READY dispatch slots
Loading

Merge Risk: 🟡 Moderate · up to a4828

The documentation build cannot pass until both new Mix pages are added to site navigation. Fix the navigation entries before merging.

Security Architecture Review

Security architecture risk: 🟡 Moderate · up to a4828

Coordinating work across several workers creates a meaningful failure-containment risk. Normal completion has safeguards, but recovery after a partial publication failure is not established.

Retained concerns

  • Medium · reliability · inferred: Mix refill consumes candidates before publication of every ready batch succeeds. If a later publication fails, this invocation has no shown rollback or requeue; the enclosing scheduler returns failure, leaving recovery dependent on terminal-run handling that is not established for this path.
Security review details

Security Blast Radius

  • inferred — The directly evidenced execution scope is the resident scheduler’s graph and configured worker lanes. The reviewed evidence does not establish a tenant boundary or an externally callable Mix entrypoint.

Trust Boundaries and Controls

  • observed — Direct Mix candidates arise from bounded waiter resolution, and queued Mix claims pass a bounded inbox-head check before placement. The Mix dispatch function itself relies on those producers for task-ID provenance before its metadata lookup.

Resilience and Maintainability Implications

  • inferred — The partial-publication path could affect graph availability if a failed run is resumed or its state reused. The reviewed source does not prove that either occurs, so this is a recovery-contract concern, not a verified attack path.

Hardening Proposals

  • proposed — Define and exercise the terminal-error, fresh-run cleanup, or rollback contract for failure after some Mix refill candidates have been consumed.
🚥 Pre-merge checks | ✅ 4
✅ Passed checks (4 passed)
Check name Status Explanation
Linked Issues check ✅ Passed Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check ✅ Passed Check skipped because no linked issues were found for this pull request.
Title check ✅ Passed The title clearly and concisely summarizes the main change: scheduling A5 HBG Mix tasks through SSBUF.
Description check ✅ Passed The description directly covers the SSBUF Mix scheduling implementation, behavior, tests, validation, and performance measurements.
✨ Finishing Touches 💡 1
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A rabbit checks each lane at dawn
It packs the slots, then hops along
Three queues hum beneath the moon
Trace marks follow every tune
When all lanes finish, carrots bloom
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Actionable comments posted: 1


  • 🪄 Fix CodeRabbit comments on this PR
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Inline comments:
Review comments at @docs/design/a5-hbg-ssbuf-mix.md:
- Around line 1-4: Update the nav configuration in mkdocs.yml to include both
the English and Chinese A5 HBG SSBUF Mix design pages so strict documentation
builds recognize them.

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Run ID: 282218ac-2443-4ea8-a87f-ad7fbfb34625

📥 Commits

Reviewing files that changed from the base of the PR and between 818ee04 and a4828dd.

📒 Files selected for processing (32)
  • docs/design/a5-hbg-ssbuf-mix.md
  • docs/investigations/2026-09-ssbuf-mix-dispatch-inlining.md
  • docs/investigations/README.md
  • docs/zh-cn/a5-hbg-ssbuf-mix.md
  • simpler_setup/tools/hbg/phases.py
  • simpler_setup/tools/swimlane_converter.py
  • src/a5/runtime/host_build_graph/aicore/aicore_executor.cpp
  • src/a5/runtime/host_build_graph/aicpu/aicpu_executor.cpp
  • src/a5/runtime/host_build_graph/common/intrinsic.h
  • src/a5/runtime/host_build_graph/docs/RUNTIME_LOGIC.md
  • src/a5/runtime/host_build_graph/host/runtime_maker.cpp
  • src/a5/runtime/host_build_graph/runtime/dispatch_payload.h
  • src/a5/runtime/host_build_graph/runtime/scheduler/scheduler_completion.h
  • src/a5/runtime/host_build_graph/runtime/scheduler/scheduler_dispatch.h
  • src/a5/runtime/host_build_graph/runtime/scheduler/scheduler_graph.h
  • src/a5/runtime/host_build_graph/runtime/scheduler/scheduler_mix.h
  • src/a5/runtime/host_build_graph/runtime/scheduler/scheduler_ready.h
  • src/a5/runtime/host_build_graph/runtime/scheduler/scheduler_ssbuf.h
  • src/a5/runtime/host_build_graph/runtime/scheduler/scheduler_types.h
  • src/common/host_build_graph/sched_phase_kind.h
  • tests/st/a5/host_build_graph/single_block_mix/kernels/orchestration/rendezvous_orch.cpp
  • tests/st/a5/host_build_graph/single_block_mix/kernels/orchestration/single_block_mix_orch.cpp
  • tests/st/a5/host_build_graph/single_block_mix/kernels/rendezvous.h
  • tests/st/a5/host_build_graph/single_block_mix/kernels/rendezvous_0.cpp
  • tests/st/a5/host_build_graph/single_block_mix/kernels/rendezvous_1.cpp
  • tests/st/a5/host_build_graph/single_block_mix/kernels/rendezvous_2.cpp
  • tests/st/a5/host_build_graph/single_block_mix/test_single_block_mix.py
  • tests/ut/cpp/a5/runtime/host_build_graph/hbg_scheduler_test_support.h
  • tests/ut/cpp/a5/runtime/host_build_graph/test_hbg_scheduler_contracts.cpp
  • tests/ut/cpp/a5/runtime/host_build_graph/test_hbg_scheduler_dispatch.cpp
  • tests/ut/cpp/a5/runtime/host_build_graph/test_hbg_scheduler_ready.cpp
  • tests/ut/cpp/common/host_build_graph/test_hbg_bind_ledger.cpp

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Comment thread docs/design/a5-hbg-ssbuf-mix.md Outdated
@zhusy54
zhusy54 force-pushed the feat/a5-hbg-ssbuf-mix branch 3 times, most recently from 4c6f41f to 7a8a8b4 Compare September 29, 2026 02:24

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审阅意见(基于 merge-base 05b5c19a0 → 7a8a8b49a)

结论:needs discussion。 机制设计自洽,测试覆盖到位(4 个 cpput target + 2 个 ST class,mask 3/5/6/7 × chain/burst + 交错 + 256 任务 rendezvous)。但有一处对外契约缺口会静默产生错误结果,另有一处顺带修掉的 profiling 老 bug 未在描述中说明。st-onboard-a5 目前还在 pending,而它是本 PR 唯一真正相关的硬件门。


一、方案理解(确认我读对了)

改动前 scheduler_resident_v0_task_shape_supported 的 active_subtasks == 1 把整类 Mix 图挡在常驻路径外,退回 AICPU legacy。本 PR 的解法:

  1. 第三条 ready 队列 SCHEDULER_MIX_QUEUE = 2,路由换成 scheduler_task_ready_queue(flags, active_mask),inbox/directory shard/batch/victim cursor 全部 2→3。
  2. is_gang 换轨 MIX|SPMD → SYNC_START|SPMD,让 Mix 不再被 prepare_dispatch_slot 的 gang 分支挡住。
  3. 联合准入 + 全 lane 原子发布 plan_mix_placement 在弹出队首之前检查「所有参与 lane 都有 FREE slot + 有空 tracker」,不满足就把队首留在队列里;dispatch 拆成 prepare-all → materialize-args-once → stage-all → 一次 barrier → commit-all。
  4. tracker 汇合完成 每条 lane 完成立刻放自己的 slot,只有 completed_mask == active_mask 的那条才写 DONE + 解依赖 + ++pending_completed。这是能解决问题的核心因果:把「slot 释放」和「task 完成」解耦。
  5. 每 lane 单调 dispatch 序列 per-slot 的 claim.generation + 1 → dispatch_sequences[lane];executor 侧 seen_generation[slot] → next_dispatch_sequence,local_ready_pop 相应改成取 generation 最小的 slot。这一步是 Mix 的必要前提(prepare 阶段要先占资源、最后一条 lane 确定后才消费序列号,per-slot +1 做不到),不是顺带改动。
  6. trace 按可执行 subtask 索引 logical_block_num/total_required_subtasks(常驻路径恒为 1 / popcount)换成 trace_index_base,trace 数组 task_count → executable_subtask_count。
  7. payload 常量项前移到 host args[48]/[49]、block_idx/block_num、task_token、src_payload 改成 per-run image 一次性初始化;配套地 Scheduler 自执行不再 invalidate 自己刚写的 payload。

选这个形态而不是复用 gang/cohort(那是为跨簇 sync-start/SPMD 设计的,簇内三核套上去要白付 gang command 的 GM round-trip),或让 AICore 自行 fan-out(DispatchPayload 是 per-core 的,一个 slot 装不下三份 args)—— 这个判断我认为是对的,但理由建议写进 PR 描述,否则下一个人要重新推一遍。


二、Must fix(或明确解释)

1. 单 AIV Mix 的 sub_block_id 由配置决定,契约未定义

scheduler_ready.h:1332:

payload->global_context.sub_block_id =
    scheduler_task_is_mix(metadata.flags) ? (slot_claim.cluster_lane == 2 ? 1 : 0) : (subtask_slot == 2 ? 1 : 0);

Mix 取物理 lane,普通任务取逻辑 subslot。对 mask 6/7 两者一致(plan_mix_placement 强制 lane == subtask);但 mask 3(AIC+AIV0)/ mask 5(AIC+AIV1)走 single_aiv 分支,pass 0 优先挑非 self_lane 的 AIV lane。而 scheduler 必须落在 lane 1 或 lane 2(scheduler_ready.h:294 的 config.scheduler_lane == 0 → return false 排除了 AIC lane),于是:

  • scheduler_lane == 1 → 唯一的 AIV subtask 落 lane 2 → sub_block_id = 1
  • scheduler_lane == 2 → 落 lane 1 → sub_block_id = 0

具体失效场景: 一个 MixedKernels{aic=K0, aiv0=K1} 的 task,K1 里写 if (get_sub_block_id(args) == 0) {...} else {...},在 scheduler_worker_id 选中 lane 1 的簇上走一支、选中 lane 2 的簇上走另一支,输出不同且都不报错。

现有测试挡不住这个:cpput MasksHaveIndependentPayloadsAndStablePhysicalContext 断言 sub_block_id == (lane == 2 ? 1 : 0),把其中一种配置钉死了(名字里的 "Stable" 名不副实);ST 侧三个 kernel 都不读 get_sub_block_id——rendezvous_N.cpp 用的是编译期 lane 常量,kernel_add/kernel_mul 是逐元素算子。也就是说没有任何测试真正执行过一个读 sub_block_id 的 Mix kernel。

建议二选一:

  • (a) 明确"Mix kernel 的 sub_block_id 是物理 AIV 编号,单 AIV Mix 不得依赖它",写进 common/intrinsic.h 的 get_sub_block_id 段落,并加一个真读 sub_block_id 的 ST kernel(mask 3 或 5)把语义锁住;
  • (b) 让单 AIV Mix 的放置对 sub_block_id 确定——按逻辑 subslot 给值,或强制 lane == subtask。

三、Should fix

2. 远端 executor 的序列缺口只会静默挂死

aicore_executor.cpp:424 的远端拾取是 if (generation == next_dispatch_sequence),不匹配就继续轮询;而自执行 lane 上同样的缺口会报 EXECUTOR_PREFERRED_SLOT_INVALID。结果是:任何"消费了 lane 序列号但没发布"或"乱序发布"的 bug,在远端 lane 上表现为 45 s HandleTaskTimeout,device log 里没有任何调度器错误——按 .claude/rules/running-onboard.md 的分类表,这会被误判成 "long/stalled op" 而不是调度器 bug。旧的 generation != seen_generation[slot] 结构上不可能出现缺口,所以这是新增的故障模式。

不必照搬自执行路径那个单条件(generation > next 会在"期望值在另一个 slot"时误报),但至少在"两个 slot 都不匹配、且存在大于期望值的 generation"时记一次错误。

3. gang_task_count 被复用成 has_mix 信号

runtime_maker.cpp:1179 现在对 MIX 也 ++gang_task_count,device 侧 scheduler_ready.h:265 读 local->has_mix = coordinator->gang_task_count != 0。当前正确只因为 scheduler_resident_v0_task_shape_supported 把 SPMD / sync-start 全挡在常驻路径外,所以常驻模式下这个计数恒等于 Mix 数。哪天形态门放宽(比如支持 SPMD),一张纯 SPMD 图会静默把 has_mix 打开,!has_mix 守卫的三条 refill 快路径全部消失,而没有任何编译期或运行期信号。

建议在 SchedulerGangCoordinator 里加一个独立的 mix_task_count,别让 has_mix 的正确性挂在另一处形态门上。字段名现在也在说谎(doc-consistency §5)。

4. scheduler_materialize_task_payload_resolved 的 block_idx/block_num 成了"校验但不生效"

scheduler_graph.h:219-231 仍然收下这两个参数并做 block_idx >= block_num → INVALID_CALLABLE 校验,但函数体里写 local_context.block_idx/block_num 的两行已经删掉(移到 host 预初始化成 0/1)。传 block_idx=1, block_num=2 现在能通过校验、然后静默按 block 0 派发。唯一调用点传的是 0, 1,建议直接把参数删掉。

5. scheduler_local_ready_pop 的 scan_start 已是死参数

scheduler_ready.h:339 是 (void)scan_start,而 aicore_executor.cpp:403 还在维护并传它(该变量在远端 scan 路径仍有用,只是这个函数不再需要)。删参数,别留 (void)。

6. trace validity 发布的内存序放松无论证

scheduler_completion.h:283 把 scheduler_gm_publish(valid,1) + scheduler_cache_barrier() 换成 scheduler_gm_store(valid,1),实际是 atomicExch + dsb((mem_dsb_t)0) → st_dev + dsb(DSB_DDR)。被删掉的注释恰好说明了第二道 barrier 存在的理由("Keep valid globally ordered before that token so host collection cannot race the final trace publication"),新注释只断言 "gm_store 自带那道 barrier",没给 DSB_DDR 足够的论证。这处改动与 Mix 无关,属于夹带——要么恢复 barrier,要么把论证写成注释里的不变量陈述。

7. 顺带修掉的 profiling bug 未说明、无回归测试

scheduler_completion.h:131-147 的「所有 invalidate 先于任何写」不只是批量化优化,它修掉了一个真实的 bug:SchedulerTaskTrace 的 cache line 3(offset 192..255)同时含 dispatch_start_cycles 和 complete_start_cycles。旧顺序是先写 complete_start_cycles,再 scheduler_observe_cache_line(&dispatch_start_cycles) 把整条 line 3 invalidate 掉。所以在 schedule_timing && phase_timing 同开(= chip swimlane level 3,正是本 PR 验证用的那一级)时,complete_start_cycles 每次都被丢弃,swimlane JSON 里这一列是脏的。

请在描述里写明这是一个独立的修复,并考虑补一条回归测试(.claude/rules/discipline.md §3)。

8. 删掉的不变量注释

scheduler_local_ready_pop 里原有的两行:

// A pending notification owns this READY slot until the same core consumes it.
// Preserve an invalid state in the token so the Executor rejects it.

描述的是 *publication = (generation << 8) | state 这个仍然存在的契约,属于 .claude/rules/comments.md 认可的"现在时事实"。重构时不该一起删。


四、Consider

  1. SchedulerRefillCandidates(bool initialize = true)(scheduler_completion.h:41-49)的半初始化比较尖锐:completed_trace_indices 任何时候都不初始化,tasks 在 initialize == false 时也不初始化。当前读写条件严格配对所以安全,但安全性完全靠调用点纪律。要么全初始化(12 × 8B,成本不高),要么注释写清"completed_trace_indices[i] 仅当 tasks[i] >= 0 && phase_timing 时有效"。

  2. runtime_maker.cpp:1314 新增的 payload 预初始化循环可以直接并进上面那个 for (i < get_worker_count()) 的 worker context 循环——少一次遍历,也避免 dispatch_payload_offset 的算式在两处各写一遍(漂移了不会有编译错误)。

  3. scheduler_drain_deferred_aiv_to_peer 的 pass 数改成 has_mix ? 1 : 2(scheduler_dispatch.h:296)是对普通路径的行为改动,描述和注释都没说为什么 Mix 图上要少一趟。

  4. Mix 队头阻塞的公平性:plan_mix_placement 要求所有参与 lane 同时有 FREE slot,而 scheduler_fill_cluster_normal_slots 会把腾出来的 slot 继续填普通任务。mask 7 的 Mix 在普通就绪工作充足时可能反复错过窗口。因为 DAG 有限、普通就绪集合终会枯竭,所以不是死锁,但延迟无上界且没有预留机制。ordinary_mix_interleaved 能触及这条路径,但 16 task 太小、断言只看数值不看延迟。

  5. PR 体积:总 churn 1849 行(Core 947 / Test 864 / Docs 38)。机制上确实难拆(三队列扩展、generation 换轨、trace 重索引三者互相依赖),但上面第 6 项 trace 按 subtask 索引、第 7 项 payload 常量前移、以及 §三.7 的 invalidate 修复,这三块都能独立成 commit 并独立验证。建议至少拆成几个有意义的 commit 并给出阅读顺序。

  6. SchedulerLocalState 从 256B 涨到 376B(含 profiling 496→616B)。AICore 栈高水位不由 static_assert 锚定(文档自己也这么说),+120B 值得在 onboard 上留意。


五、描述与验证的两处对照

  • 描述说 "A5 simulation could not run in this environment because g++-15 is unavailable",但 CI 的 st-sim-a5sim 两个 runner 都过了,新 ST 用例(platforms: ["a5sim","a5"])确实跑到了——这一条可以从描述里划掉。
  • 性能说明自己标注了 "final revision has not been rebenchmarked",诚实,但意味着这个 PR 目前没有可引用的性能结论。如果最终版重测仍然是 Mix chain 无加速(304→310 µs / 367→370 µs),按 .claude/rules/discipline.md §4 建议在 docs/investigations/ 落一条记录并更新 README 索引。

六、合并路径

  1. 作者确认 sub_block_id 的意图契约(物理 or 逻辑),据此补文档 + 覆盖,或改放置逻辑 —— 这一条定了就能转 approve。
  2. Should-fix 2~8 都很小,建议在本 PR 收掉;其中第 3(gang_task_count)和第 4(死参数)建议必须收,因为它们属于"现在正确、以后静默出错"的类型。
  3. 等 st-onboard-a5 出结果。全绿的其余 job 里没有一个真正跑过 A5 常驻 Mix 的硬件路径。

附:pto-isa pin

pto_isa.pin 固定在 c0d7148e95ef73bd12a73165fdce4b723a3b7e72,本 PR 未修改。新增的 kernels/rendezvous.h 引入了 #include <pto/pto-inst.hpp>(ADDED 信号),但该头已被仓内多个既有 kernel 引用,当前 pin 必然提供它——无需 bump,确认一下即可。没有 pto-isa 头文件路径迁移(CHANGED,最强的 bump 信号)。

Comment thread src/a5/runtime/host_build_graph/aicore/aicore_executor.cpp Outdated
@zhusy54
zhusy54 force-pushed the feat/a5-hbg-ssbuf-mix branch from 7a8a8b4 to f0cd206 Compare September 29, 2026 07:26
- Admit Mix when each participating lane has capacity and publish
  independent payloads in lane dispatch order.
- Reclaim completed lanes promptly and resolve dependencies after every
  Mix subtask completes while preserving ordinary refill behavior.
- Attempt direct Mix refill using all required lane slots and a tracker
  before claiming queued Mix; queue the candidate if placement fails.
- Count Mix independently of gang tasks and keep worker payload setup
  together while removing unused materialization and scan parameters.
- Share dispatch metadata, batch trace invalidations, and reuse ready
  snapshots to reduce scheduler memory traffic.
- Index profiling by executable subtask and publish trace validity with
  st_dev while keeping the existing per-subtask completion timing.
- Cover mixed DAGs, rendezvous, direct Mix refill, and scheduler contracts
  in tests; yield during simulated rendezvous polling so peer cores run.
@zhusy54
zhusy54 force-pushed the feat/a5-hbg-ssbuf-mix branch from f0cd206 to 319f0af Compare September 29, 2026 09:07

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复查意见(第二轮)

对比 7a8a8b49a → 319f0af51(已 rebase 到新 main,merge-base 05b5c19a0 → 02fd1f63e)。

结论:approve。


一、先撤回我上一轮的一个错误结论

我把「单 AIV Mix 的 sub_block_id 契约未定义」列为 Must fix,这是误报,撤回。

common/intrinsic.h 里本来就写着(116 行与 167-168 行,本 PR 之前就已存在):

// Not meaningful for AIC kernels or single-AIV tasks.

 * Single-AIV tasks have no intra-cluster communication, so sub_block_id
 * has no meaning and should not be used.

契约早已存在,而且正是我"建议补充"的那一条。所以 mask 3 / 5 下由物理放置决定 sub_block_id 不构成缺陷——kernel 本来就不允许读它。没有动 intrinsic.h 是正确的,抱歉造成的额外核对成本。

我上一轮漏读的原因:读 intrinsic.h 时只 grep 了 PAYLOAD_*_CONTEXT_INDEX / MAX_TENSOR_ARGS / args[ 这类 args 布局符号,没有读 sub_block_id 自身的上下文。

撤回这条后,本 PR 已无 Must fix。


二、已处理的意见

上一轮意见 处理情况
Should-fix 3 gang_task_count 被复用成 has_mix 信号 SchedulerGangCoordinator 新增独立 mix_task_count(占用原 reserved0),gang_task_count 恢复只数 gang;has_mix 改读 mix_task_count,并加了 DetectsMixIndependentlyOfGangTasks 把两者的独立性锚住 ✅
Should-fix 4 block_idx/block_num 校验但不生效 参数删除,校验收缩为 dispatch_payload == nullptr || function_bin_address == 0 ✅
Should-fix 5 scan_start 死参数 参数删除;变量在远端 scan 路径正确保留 ✅
Should-fix 6 trace validity 内存序放松无论证 注释改写成两段式论证——前置 scheduler_cache_barrier() 负责 trace lines → valid 的顺序,gm_store 自带的 store barrier 负责 valid → pending_completed 的顺序。论证成立,接受 ✅
Should-fix 8 删掉的不变量注释 已恢复(措辞调整为 "A local notification owns this slot until it is consumed here",语义保留)✅
Consider 9 completed_trace_indices 半初始化 加了有效性条件注释 ✅
Consider 10 payload 初始化循环与重复索引算式 合并进 worker context 循环,并改用 context.dispatch_payload_offset + slot * sizeof(DispatchPayload)——重复算式彻底消除,比我建议的更干净 ✅
Consider 11 drain pass 2 → 1 无说明 加了注释说明 Mix completion 走主 completion scan、pass 1 的直接替换只对 ordinary-only 图有效 ✅

三、额外的自主改进(我没提,值得肯定)

新增 scheduler_fill_mix_after_completions,把 direct 候选与队列 claim 的顺序倒过来(原先队列先、direct 后 → 现在 direct 先、队列后)。

这个新顺序才是对的:候选被 scheduler_resolve_completion 采纳的前提就是「快照时整个 Mix 队列系统为空」,所以它本来就该先于"快照之后才被别的 Scheduler push 进来"的任务。旧顺序反而可能让后到者抢先。

配套地 RUNTIME_LOGIC.md 把原先那句无法保证的强声明("Later arrivals do not precede it")删掉了,换成诚实的 "Queue arrivals between that snapshot and a failed placement can precede the candidate after it joins the queue"。文档承认自己的弱保证,这比声明一个守不住的强序更有价值。

另加 3 个 Mix 测试(DirectCandidatePrecedesMixQueuedAfterResolve / DirectCandidateQueuesWhenRequiredLaneIsBusy / LastLaneAloneResolvesDependency)。


四、未处理(均不阻塞合并)

1. 远端 executor 的序列缺口仍然只会静默挂死

aicore_executor.cpp:419 一带未改。自执行 lane 上的序列缺口报 EXECUTOR_PREFERRED_SLOT_INVALID;远端 lane 的 if (generation == next_dispatch_sequence) 不匹配就继续轮询,最终以 45 s HandleTaskTimeout 收场,device log 里没有任何调度器错误——按 .claude/rules/running-onboard.md 的分类表会被误判成 "long/stalled op"。

不阻塞,但建议单独开一个 issue:这条诊断性缺口对整个常驻调度器都适用,不只 Mix(旧的 seen_generation[slot] 结构上不可能出现缺口,所以它是随 per-lane 严格序列一起引入的),值得独立处理而不是塞进本 PR。

2. invalidate 修复仍未在描述里说明

描述里只有 "batch trace invalidations"。但 scheduler_completion.h 的「所有 invalidate 先于任何写」实际修掉了一个独立的 bug:SchedulerTaskTrace 的 cache line 3(offset 192..255)同时含 dispatch_start_cycles 与 complete_start_cycles,旧顺序先写 complete_start_cycles 再 observe_cache_line(&dispatch_start_cycles) 把整条 line invalidate 掉,于是在 schedule_timing && phase_timing 同开(= chip swimlane level 3)时该字段每次都被丢弃。

建议在描述里单独列一条,让它在 git history 里可检索;回归测试可选。

3. 其余 Consider 未回应

PR 体积(仍单 commit,1704/234)、Mix 队头公平性无预留机制、SchedulerLocalState +120B 的 AICore 栈高水位。都可以留到后续。

4. 描述里一处与 CI 事实不符

"A5 simulation could not run in this environment because g++-15 is unavailable" 这句仍在,而 CI 的 st-sim-a5sim 四个 runner 全部通过、新 ST 用例(platforms: ["a5sim","a5"])确实跑到了。建议删掉或改成"本机环境无法运行,CI 已覆盖"。


五、CI

全绿,包括上一轮还在 pending 的 st-onboard-a5。 描述的 Validation 也补齐了 rebase 后的硬件结果(single-block Mix 与 Mix/SPMD 图执行 3 passed;cpput 153 passed / 4 targets)。


六、结论

唯一的 Must fix 是我的误报;8 条修正全部落地,其中 2 条做得比建议更好;额外的顺序修正与文档弱保证声明是主动改进;最关键的硬件门 st-onboard-a5 已通过。

approve。 上面第 1 条建议单独开 issue,第 2、4 条改描述即可,不必再转一轮 review。

@ChaoZheng109
ChaoZheng109 merged commit 3fa8b54 into hw-native-sys:main Sep 30, 2026
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