frank-primary: DFlash2 load attempt + fp8 verdict + compile blocker narrowed

DFlash2: fetched incoai/GLM-5.3-Flash-DFlash2 (2,342,169,800 B, sha256 matches the
Hub LFS oid) and tried --speculative-config {"method":"dflash","model":"/draft"}.
Config and drafter are accepted; the worker dies with 'Model does not support
EAGLE3 interface' - so the only gap is the target-side aux-hidden-state contract
(set_aux_hidden_state_layers + per-layer capture + the two-value forward return,
as deepseek_v2.py demonstrates twice in this image). Recorded the exact interface,
the GLM-specific unknown (what the single-stream state entering layer k means for
an mHC multi-stream trunk) and the honest expectation: no speedup on a
token-proportional pointwise bound.

fp8 KV: recorded the deciding measurement - the fork's KV reserve model is
dtype-blind (the fp8 boot printed the identical 1760 MiB / 13600 B-per-token plan),
so fp8 cannot buy capacity even if the gfx12 MLA path were rewritten. Verdict: do
not spend effort there.

Compile blocker narrowed from 'a latent GLM bug' to dynamo's name map: the
KeyError is thrown by torch/_dynamo/output_graph.py's nn_modules lookup (:3000,
registered :1259/:1384, _modules[..] prefixes stripped :1225), i.e. the compiler
cannot resolve a submodule by name while tracing the decoder layer. Next step is
TORCHDYNAMO_VERBOSE=1, with the note that the scratch launcher resets ENVARGS.

tests/run.sh: 362 seams pass.
This commit is contained in:
Comrade Chief Designer
2026-09-30 12:49:26 -07:00
parent bd8c72ff47
commit 1c18b9c808
3 changed files with 133 additions and 28 deletions
@@ -175,18 +175,30 @@ What the boots established, in order (each one ~7 min):
`RuntimeError: Graph breaks are not supported with aot compile`, because this
build runs AOT compile by default and AOT refuses breaks.
3. **01+02+03 with `VLLM_COMPILE_FULLGRAPH=0 VLLM_USE_AOT_COMPILE=0` traces the
trunk successfully** (`Dynamo bytecode transform time: 1.08 s`) and then dies in
`profile_run` with `KeyError: 'in_proj_qkvbfg_a'` at
`glm5next/common/model.py:456` (the KDA layer's merged projection,
`kda.py:217`) — a dict/registry lookup keyed by attribute name that the eager
path never reaches, i.e. **a latent bug the compile exposes, not a dynamo
limit**.
trunk successfully** (`Dynamo bytecode transform time: 1.08 s`) and then dies on
the decode forward with `KeyError: 'in_proj_qkvbfg_a'` (`Glm5NextModel.forward`
line 748 calling the decoder layer at line 456). `in_proj_qkvbfg_a` is the KDA
layer's merged column-parallel projection (`kda.py:217`, called at :407) — a real
submodule attribute name, also present in the `load_weights` shard table
(`model.py:780-785`). Reading the full traceback (the reported line is inside
dynamo-rewritten code) traces the throw to dynamo's own name→module map:
`torch/_dynamo/output_graph.py` registers into `nn_modules` at :1259/:1384,
looks up with `self.nn_modules[node.target]` at :3000 (a bare-name `KeyError`
when absent), and documents stripping `_buffers[..]/_parameters[..]/_modules[..]`
from those names at :1225. So the compiler is failing to **resolve a submodule by
name** while tracing the GLM decoder layer; whether the root cause is the fork's
module tree or dynamo's registration is not yet settled. The next step is the one
torch itself suggests in that error — `TORCHDYNAMO_VERBOSE=1` for the internal
stack trace (and note the launcher resets `ENVARGS`, so it must be added inside
`serve_glm_autoround.sh`'s COMPILE_PATCH branch rather than in the outer
environment).
That last row is the state of the work: the remaining blocker is a real bug in the
fork's mHC/KDA wiring, and it must be fixed (plus whatever follows it) before the
changelist can boot. Two verified facts make the payoff concrete: `suppress_errors`
does **not** cover graph breaks (only `fullgraph=False` does), and the GLM trunk can
never satisfy `fullgraph` because its indexer metadata syncs to host
That last row is the state of the work: the changelist is one unresolved
submodule-name lookup away from booting, and it must be cleared (plus whatever
follows it) before the compile payoff can be measured. Two verified facts make the
rest of the shape concrete: `suppress_errors` does **not** cover graph breaks (only
`fullgraph=False` does), and the GLM trunk can never satisfy `fullgraph` because
its indexer metadata syncs to host
(`glm5next/amd/sparse_indexer.py:263,419`: `int(...max().item())`).
### Two structural constraints on any further fork work
@@ -221,10 +233,48 @@ layer indices, the same interface `deepseek_v2.py` (also MLA+MoE) implements —
capture at `idx in self.aux_hidden_state_layers` in the layer loop. `glm5next`
implements neither.
Expected benefit is **not** assumed: DFlash2 amortizes a draft block (8 tokens) over
one verification pass, and per the profile above a verification pass costs pointwise
work proportional to tokens — the same reason MTP4 was flat. Measure it; do not
budget on it.
**The load was tried, and the gap is exactly one interface.** Payload fetched to
`/home/dank/models/GLM-5.3-Flash-DFlash2` and hash-verified (`model.safetensors`
2,342,169,800 B, sha256 `b038e1d9…` = the Hub's LFS oid). Booting the engine with
`--speculative-config '{"method":"dflash","model":"/draft","num_speculative_tokens":8}'`
accepts the config and the drafter and dies at worker init with:
```
RuntimeError: Model does not support EAGLE3 interface
```
So nothing about the drafter, the method name, or the payload is wrong — the GLM
trunk simply does not implement the aux-hidden-state contract the dflash runner
requires. The reference is in this same image, twice: `deepseek_v2.py`
(`set_aux_hidden_state_layers` / `get_eagle3_aux_hidden_state_layers` at :1948-1951,
capture at :1554 and :1579) and the fork's own `qwen4_exp` trunk. The contract is
small:
- `self.aux_hidden_state_layers: tuple[int, ...]` on the trunk, default `()`, set
by the wrapper's `set_aux_hidden_state_layers()`;
- in the layer loop, `if idx in self.aux_hidden_state_layers: aux_hidden_states.append(<single-stream state entering layer idx>)`
(DeepSeek appends `hidden_states + residual`, with a TP all-gather fixup when the
rank holds fewer tokens than `positions`);
- `Glm5NextModel.forward` returns `(hidden_states, aux_hidden_states)` when the
list is non-empty;
- `get_eagle3_aux_hidden_state_layers()` supplies a default triple when the drafter
config omits `target_layer_ids` (this drafter provides `[5, 14, 24, 33, 42]`, so
the runner derives trunk indices `[6, 15, 25, 34, 43]`).
**The GLM-specific unknown** is what "the single-stream state entering layer k"
means for a trunk whose layers carry mHC multi-stream state: DeepSeek's
`(hidden_states, residual)` pair has no counterpart here — GLM's decoder layer
returns `(hidden_states, residual, post, comb)` with `hc_expand`/`hc_pre` mixing
`hc_mult` streams, so the plausible answer is the pre-mHC single-stream input `x`
(4096-wide, matching the drafter's `hidden_size`), not a post-layer value. That is
a semantic choice to validate by acceptance rate, not by inspection.
**Budget no speedup.** Per the profile above, a verification pass pays pointwise
cost proportional to its token count — the same reason MTP4 measured flat — and
MTP4's acceptance was already excellent (3.76-4.90). The port is worth doing as
*enabling work* (it is the prerequisite for any spec decode on this endpoint, and
it is small), not as a performance fix, and the honest expectation on this shape is
flat decode with a prefill regression like MTP's until the pointwise mass is fused.
Note also that the KV-cap patch's predecessor arithmetic in
[[dankserver-qwen38-fp8-expert-offload-tuning]] should be read the same way: its
@@ -275,17 +325,32 @@ newest GLM dialect the fork ships (`glm45`/`glm47` exist for both).
## Fork traps found (for the engine authors)
1. **`--kv-cache-dtype fp8` is illegal on gfx12 with this model.** The
`ROCM_AITER_MLA_SPARSE` backend's `_use_rocm_sparse_triton()` requires a
non-fp8 KV cache, and that rope-free Triton path is the **only** MLA decode
available on gfx12: aiter's MLA decode op is registered under
`@if_aiter_supported`, which is gated on **CDNA > 2**
1. **`--kv-cache-dtype fp8` is illegal on gfx12 with this model — and it buys
nothing even if fixed.** The `ROCM_AITER_MLA_SPARSE` backend's
`_use_rocm_sparse_triton()` requires a non-fp8 KV cache, and that rope-free
Triton path is the **only** MLA decode available on gfx12: aiter's MLA decode
op is registered under `@if_aiter_supported`, which is gated on **CDNA > 2**
(`is_aiter_found_and_supported()` → `get_cdna_version() > 2`). With fp8 KV
the MTP draft step demands an op that cannot exist here:
`RuntimeError: Worker failed with error ''_OpNamespace' 'vllm' object has no
attribute 'rocm_aiter_mla_decode_fwd''`. KV dtype therefore stays auto/bf16.
(`VLLM_ROCM_USE_AITER_MLA=1` does **not** help — the umbrella gate is the
CDNA check, not the env var.)
- **The capacity payoff is measured at zero.** The point of fp8 KV is fitting
more tokens in the same reserve, and this fork's reserve model is
**dtype-blind**: the fp8 boot printed the *identical* plan line as bf16 —
`KV reserve 1.76 GiB (13600 B/token x 131072 + mamba pages)`. The reserve is
dominated by the per-sequence KDA state (34 linear-attention layers) and the
DSA indexer's pools, not by the MLA KV bytes those 13,600 B/token barely
cover — so halving the KV dtype cannot move it.
- **What a fix would take, if it were ever wanted**: a new fp8 path in the
rope-free Triton kernels (`rocm_sparse_attn_prefill` / `rocm_sparse_attn_decode`
in `v1/attention/ops/rocm_aiter_mla_sparse.py`) that dequantizes pages
in-kernel, plus loosening `_use_rocm_sparse_triton()`. The fork's
`_r4d_fp8_paged_mqa_logits` shows the author already has an fp8 MQA-logits
path, but the sparse-MLA backend is not wired to it. Verdict 2026-09-30:
**do not spend effort here** — the payoff is capacity, and the reserve is
dtype-blind.
2. **The plan's KV reserve under-models this model, and the cap enforces the
mistake.** The plan charges 13,600 B/token + a small mamba term, but GLM
carries a per-sequence KDA state (34 linear-attention layers) and, under MTP,
@@ -322,6 +387,16 @@ podman logs frank-primary-glm 2>&1 | grep "expert_lru.py"
# boot: ~7 min warm page cache, longer cold; health returns 503 while loading
curl -s -o /dev/null -w "%{http_code}\n" http://127.0.0.1:7770/health
# experiment windows (production stopped + `systemctl mask --runtime`, which
# self-clears at reboot) ran from the host-side scratch launcher
# /home/dank/serve_glm_autoround.sh: env knobs MAXLEN SEQS NBATCH UTIL KVBYTES
# KVDTYPE SPEC SPECJSON_FILE TOOLPARSER REASONINGPARSER TELEM GCHUNKS GLANES
# PROFDIR GLM_PATCH_MOUNT COMPILE_PATCH GATHER_PATCH DRAFT_MOUNT ENVARGS.
# DRAFT_MOUNT=1 mounts /home/dank/models/GLM-5.3-Flash-DFlash2 at /draft;
# SPECJSON_FILE passes a whole --speculative-config JSON (JSON with no spaces,
# word-split by the launcher's unquoted $EXTRA).
bash /home/dank/serve_glm_autoround.sh
```
Boot gate: the engine refuses a legal-looking shape in two measured ways — the
+15
View File
@@ -66,6 +66,21 @@
capture (`set_aux_hidden_state_layers` / per-layer capture, as `deepseek_v2.py`
demonstrates). No speedup is budgeted: a verification pass pays pointwise cost
proportional to its token count.
- **DFlash2 tried, and the gap is exactly that one interface.** Payload fetched
and hash-verified (`/home/dank/models/GLM-5.3-Flash-DFlash2`, 2,342,169,800 B,
sha256 `b038e1d9…` = the Hub's LFS oid). Booting with
`--speculative-config '{"method":"dflash","model":"/draft","num_speculative_tokens":8}'`
accepts the config and the drafter and dies at worker init with
`RuntimeError: Model does not support EAGLE3 interface` — nothing about the
drafter, the method or the payload is wrong; the trunk simply does not
implement the aux-hidden-state contract.
- **Compile blocker narrowed to dynamo's name map.** The `KeyError:
'in_proj_qkvbfg_a'` (see above) is thrown from `torch/_dynamo/output_graph.py`'s
`nn_modules` name lookup (:3000, registered at :1259/:1384, with `_modules[..]`
prefixes stripped at :1225) — i.e. the compiler cannot resolve a submodule by
name while tracing the GLM decoder layer. Next step is `TORCHDYNAMO_VERBOSE=1`
(torch names it in the error), noting the scratch launcher resets `ENVARGS` so
it must be set inside the script's COMPILE_PATCH branch.
- Measured and rejected: **MTP4** (the head loads, arch resolves to
`Glm5NextMTPModel`, acceptance is excellent at mean length 3.76-4.90 — but
decode was unchanged (9.6-11.2 vs 10.0) while prefill COLLAPSED 918 -> 255.