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:
@@ -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
|
||||
|
||||
@@ -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.
|
||||
|
||||
Reference in New Issue
Block a user