4 Commits

Author	SHA1	Message	Date
rob thijssen	93421f48e2	Stage 7b-ii: ColumnParallel + RowParallel sharded linear primitives ... Adds harness/tp/sharded_linear.rs with ShardedLinear — a Megatron-LM style sharded wrapper over candle_nn::Linear. Two constructors: - load_column: splits the output dimension. Each rank holds rows [r*out/N .. (r+1)*out/N] of the weight, plus its slice of the bias. Forward = local matmul; output is naturally sharded; downstream consumer either accepts the shard (next layer is column-parallel) or merges via all-gather later. - load_row: splits the input dimension. Each rank holds cols [r*in/N .. (r+1)*in/N] of the weight; bias lives only on rank 0 so the post-all_reduce sum carries it exactly once. Forward produces a partial output that the caller reduces via NCCL. Both constructors bail with a clear error when divisibility doesn't hold — the precondition mistral.rs's first qwen3-next-tp commit made explicit. The path included in the error is the VarBuilder prefix, so the operator sees exactly which projection failed ("column-parallel 'model.layers.0.self_attn.q_proj': out_features=..."). 5 unit tests on CPU verify the math against an unsharded reference: - column shard produces the expected slice of the full matmul - row partials sum to the unsharded result - row bias appears only on rank 0 - divisibility violations bail (column + row) forward_with_comm() is stubbed for row-parallel (CUDA-only) — wiring the actual cudarc::nccl all_reduce against candle's Tensor lands in 7b-iii alongside the model assembly, where the model holds the Comm in scope. ColumnParallel's forward_with_comm just delegates to the local matmul (no collective needed). Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>	2026-05-19 17:07:19 +03:00
rob thijssen	05e15f3597	Stage 7b-i: dense safetensors Qwen3 load path ... Adds the bf16/fp16 safetensors path alongside the existing GGUF quantized one. The harness now dispatches by ModelSpec.quant: - Some(_) → GGUF (pre-quantized, single-GPU only path, unchanged). - None → safetensors dense (new). The dense path uses candle-transformers::models::qwen3::ModelForCausalLM verbatim, fed via VarBuilder::from_mmaped_safetensors over the files listed in `model.safetensors.index.json` (sharded layout) or the single `model.safetensors` fallback. dtype is bf16 to match the canonical Qwen3 HF distribution dtype. tokenizer.json is fetched from the same repo (no -GGUF suffix to strip). ModelArch gains a Qwen3Dense variant; the forward signature mirrors QuantizedQwen3Weights (same `forward(&Tensor, offset)` → last-position logits), so run_inference / run_inference_streaming just add a parallel match arm — no shape changes downstream. This is the foundation 7b-ii (ColumnParallel/RowParallel) builds on: because the source is dense safetensors that can be byte-sliced per rank, the TP work avoids the GGUF super-block alignment problem entirely. Vanilla GGUF inference keeps working unchanged. validate-neuron.sh learns the dense path: pass an empty third arg (quant) and the script omits the `quant` field from the load payload, triggering the dense dispatch. Example: script/validate-neuron.sh beast.hanzalova.internal Qwen/Qwen3-0.6B '' Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>	2026-05-19 17:03:59 +03:00
rob thijssen	da068ded6d	Stage 7a-ii: real NCCL handshake behind the worker pool ... Wires cudarc::nccl into the TP worker lifecycle introduced in 7a-i. With --features cuda the leader and its workers now establish a live NCCL communicator end-to-end; without the feature the same code paths return Error{kind="cuda_feature_not_enabled"} so a misconfigured build is obvious instead of silently no-op. NCCL state machine (harness/tp/nccl_state.rs) is shared between the worker process and the leader's pool: - generate_comm_id_hex() mints an Id::new() on the leader. - NcclState::init parses 256 hex chars → [c_char; 128] → Id::uninit, opens a CudaContext on the configured device, calls Comm::from_rank with the supplied (rank, world_size, id). NCCL blocks until every rank has joined. - NcclState::sanity_check runs one all_reduce(1u32, Sum); the leader asserts every rank reports observed_sum == world_size. - NCCL handles serialised under Mutex; unsafe impl Send/Sync gates the Comm across spawn_blocking boundaries (NCCL is move-safe; only concurrent op issuance is unsafe). WorkerPool::init_nccl orchestrates the rendezvous: 1. Write Init { comm_id } to every worker's stdin (no await yet). 2. Leader rank 0 calls its own Comm::from_rank in spawn_blocking, concurrently with workers. 3. NCCL handshake completes for all ranks simultaneously. 4. Leader collects InitOk responses. WorkerPool::nccl_sanity_check follows the same pattern over all_reduce, validating world_size == observed_sum on every rank. Worker.send_only / Worker.recv_only split out from the previous monolithic Worker.request so the leader can interleave its own NCCL work with the worker calls — required because NCCL blocks during init. Tests: - 4 hex roundtrip unit tests for the wire encoding. - The 7a-i "not implemented" expectation now reads "cuda_feature_not_enabled" on the local dev box (no CUDA), or accepts InitOk on a cuda-built test binary. - New cuda-integration test in tp_worker_lifecycle_cuda.rs covers the real init + sanity round-trip; gated on the cuda-integration feature so default CI doesn't try to NCCL. Verifiable on beast (2× RTX 5090): cargo test -p neuron --features cuda-integration \ --test tp_worker_lifecycle_cuda Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>	2026-05-19 16:40:01 +03:00
rob thijssen	2a7ede0232	Stage 7a-i: TP worker lifecycle scaffolding ... Leader → worker process plumbing for tensor parallelism. The neuron binary picks up two modes: default (the existing daemon, axum + HTTP) and `--worker` (a bare RPC loop driven over stdin/stdout). The leader spawns one worker per non-zero NCCL rank via tokio::process::Command on the same binary path (production: /proc/self/exe; tests: env!("CARGO_BIN_EXE_neuron")) and talks to each over newline- delimited JSON. Protocol (harness/tp/rpc.rs) is serde-tagged from the start — WorkerRequest::{Ping, Init, NcclSanityCheck, Shutdown} and WorkerResponse::{Pong, InitOk, NcclSanityResult, Bye, Error}, both `#[serde(tag = "op", rename_all = "snake_case")]`. Adding ops in 7b/7c is purely additive; unknown ops on the wire fail to parse (verified in unit tests). 7a-i scope: - WorkerPool::spawn(binary, world_size, devices) forks ranks 1..N as subprocesses, captures stdin/stdout, kills on drop. - ping_all() round-trips a Ping to every worker and validates the returned rank. - shutdown() sends Shutdown to each worker, awaits Bye, reaps. - Worker mode: parse Ping/Shutdown, return Pong/Bye; Init and NcclSanityCheck return Error{kind="not_implemented_7a_i"} so a 7a-ii binary speaking the same wire is a drop-in replacement (the kind field signals "real NCCL lands in the next commit"). - CandleHarness::load_model refuses tensor_parallel > 1 with a clear message until 7b is in. Three integration tests in tests/tp_worker_lifecycle.rs cover spawn/ ping/shutdown for 2- and 3-worker pools, plus the not_implemented_7a_i contract test for Init. Seven rpc serde unit tests assert the wire shape (op tags, field names, unknown-op rejection). All pass on the dev host; no CUDA required. Stage 7a-ii (next): the real NCCL Comm::from_rank wiring behind the existing Init/NcclSanityCheck op surface, CUDA-gated. Verifiable on beast's 2×5090. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>	2026-05-19 15:53:00 +03:00