frank-primary: pin the -ot override set to the real tensor names

Discovery, not guesswork: dump the GGUF v3 headers of the fetched parts
(scripts/dump-gguf.py, added — a dependency-free reader that never
touches tensor data, so a 50 GiB part scans in milliseconds) before
the first load.

What the dump says (parts 2-3, 2026-09-26):

- The 51B-param PLE n-gram table is ONE tensor: per_layer_token_embd.
  weight, dims [160, 320001536], Q8_0, 54.4 GiB — exactly the whole of
  part 3. It is the same tensor the shared MTP head borrows, so the
  =CPU override is required for placement AND for the draft load
  (GPU-resident borrow: "invalid vector subscript").
- The model is qwen4exp, 512 experts, top-10 routing
  (qwen4exp.ple.ngram_size=3, heads_per_ngram=8).
- Part 1 is metadata-only (ntensors=0); parts 2-6 carry tensors.

The placeholder pattern ngram_embeddings matched nothing — dropped from
OT_OVERRIDES (env, serve-script default, seam, AGENTS.md, runbook,
LLM index) before it could masquerade as a working override at load
time. Deployed set: exps=CPU,per_layer_token_embd.weight=CPU.

Suite: 346 green.
This commit is contained in:
Frank
2026-09-26 19:51:57 -07:00
parent 8500600d09
commit a9b94a79eb
7 changed files with 137 additions and 18 deletions
+107
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@@ -0,0 +1,107 @@
#!/usr/bin/env python3
"""Dump GGUF part headers: split metadata, tensor names/dims/types/bytes.
Reads ONLY the header region (metadata + tensor-info table); tensor data is
never touched, so a 50 GiB part scans in milliseconds. Split GGUFs are valid
GGUFs per part; part 1 of this payload is metadata-only (ntensors=0) and
parts 2-6 carry the tensors. Confirmed layout for this payload: GGUF v3 —
magic, u32 version, u64 ntensors, u64 nkv, then kvs (v3: u64-length strings),
then tensor infos (v3: u64-length names).
"""
import struct, sys, traceback
TYPE_SIZE = {0:4,1:2,2:1,3:1/2,4:4,5:8,6:2,7:1,8:0.4375,9:1.4375,10:1,11:0.5,
12:2,13:4/3,14:2,15:2,16:4,17:2,18:2,19:1,20:2,21:1,22:2,23:2,
24:2,25:1.0625,26:1,27:1.375,28:2,29:2,30:2,31:4,32:8,33:2.125,
34:2.5,35:2,36:2.375,37:1.5625,38:2.3125,39:2.1875,40:0,41:1.75,
42:1.75,43:1.8125,44:2,45:2.25,46:1.5,47:2.0625,48:2.625,49:1.0625,
50:2.3125,51:2.875,52:2,53:2.3125,54:2.75,55:2.5,56:2.875,57:2.25,
58:2,59:3.8125,60:2.8125,61:1.5625,62:1.5,63:0.5}
class P:
def __init__(self, f):
self.f = f
self.ver = 2
def rd(self, n):
b = self.f.read(n)
if len(b) != n:
raise EOFError(f"short read {len(b)}/{n}")
return b
def u8(self): return self.rd(1)[0]
def u32(self): return struct.unpack("<I", self.rd(4))[0]
def u64(self): return struct.unpack("<Q", self.rd(8))[0]
def f32(self): return struct.unpack("<f", self.rd(4))[0]
def f64(self): return struct.unpack("<d", self.rd(8))[0]
def s(self):
# GGUF v3 strings carry a u64 length; v2 used u32.
n = self.u64() if self.ver >= 3 else self.u32()
return self.rd(n).decode("utf-8", "replace")
def val(self, t):
# GGUF kv value types: 0 u8, 1 i8, 2 u16, 3 i16, 4 u32, 5 i32,
# 6 f32, 7 bool, 8 string, 9 array, 10 u64, 11 i64, 12 f64.
if t == 8: return self.s()
if t == 9:
et = self.u32(); n = self.u64()
return [self.val(et) for _ in range(n)]
if t == 0: return self.u8()
if t == 1: return struct.unpack("<b", self.rd(1))[0]
if t == 2: return struct.unpack("<H", self.rd(2))[0]
if t == 3: return struct.unpack("<h", self.rd(2))[0]
if t == 4: return self.u32()
if t == 5: return struct.unpack("<i", self.rd(4))[0]
if t == 6: return self.f32()
if t == 7: return self.u8()
if t == 10: return self.u64()
if t == 11: return struct.unpack("<q", self.rd(8))[0]
if t == 12: return self.f64()
raise ValueError(f"unknown kv type {t}")
def main(path):
tensors = []
kvs = {}
with open(path, "rb") as f:
p = P(f)
magic = p.rd(4)
assert magic == b"GGUF", magic
p.ver = p.u32()
ntens = p.u64()
nkv = p.u64()
for _ in range(nkv):
k = p.s()
kvs[k] = p.val(p.u32())
for _ in range(ntens):
name = p.s()
nd = p.u32()
dims = [p.u64() for _ in range(nd)]
t = p.u32()
off = p.u64()
numel = 1
for d in dims: numel *= d
tensors.append((name, dims, t, numel))
print(f"== {path} (gguf v{p.ver}, {ntens} tensors, {nkv} kv)")
for k in ("general.architecture", "general.name", "split.no", "split.count",
"split.tensors", "qwen4exp.expert_count", "qwen4exp.expert_used_count",
"qwen4exp.ngram.tensors"):
if k in kvs: print(f" kv {k} = {kvs[k]}")
ngram_kvs = {k: v for k, v in kvs.items() if "ngram" in k.lower()}
if ngram_kvs: print(" ngram kvs:", ngram_kvs)
big = []
for name, dims, t, numel in tensors:
big.append((numel * TYPE_SIZE.get(t, 0), name, dims, t, numel))
big.sort(reverse=True)
print(f" -- {min(12, len(big))} largest of {len(big)}:")
for bytes_, name, dims, t, numel in big[:12]:
print(f" {bytes_/2**30:9.3f} GiB {name} dims={dims} type={t} ({numel:,} elems)")
named = [(b, n, d, t) for b, n, d, t, e in big
if any(s in n.lower() for s in ("ngram", "ple", "token_embd", "exps"))]
if named:
print(" -- ngram/ple/embed/experts-named:")
for bytes_, name, dims, t in named[:20]:
print(f" {bytes_/2**30:9.3f} GiB {name} dims={dims} type={t}")
for pth in sys.argv[1:]:
try:
main(pth)
except Exception:
print(f"== {pth}: FAILED")
traceback.print_exc()
+16 -12
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@@ -43,19 +43,23 @@ SPEC_DRAFT_N_MAX=2
# RAM (computed there — the x4-pair measurement: streaming over PCIe loses,
# computing in RAM does not). OT_OVERRIDES is comma-separated
# <tensor-pattern>=<backend> pairs passed as repeated --override-tensor
# flags:
# * exps=CPU — the routed experts. ~100 GiB at Q8, read once per token;
# the CPU backend computes them from page cache.
# * the n-gram embedding block (the 51B-param PLE table) — sparse row
# lookups, tiny PCIe traffic from CPU RAM; NEVER pin with a GPU target
# (the 23 -> 13.4 t/s regression).
# * per_layer_token_embd.weight=CPU — REQUIRED by the shared MTP head's
# borrow path: GPU-resident, it crashes the draft load with
# "invalid vector subscript" (llama.cpp PR #28243).
# The exact tensor pattern for the n-gram block was discovered at load time
# on 2026-09-26 (see the runbook); this list is the deployed set.
# flags. Both overrides are pinned by the header dump of parts 2-3
# (2026-09-26, /home/dank/models/dump-gguf.py — GGUF v3, 512 experts
# top-10, qwen4exp.ple.ngram_size=3, heads_per_ngram=8):
# * exps=CPU — the routed experts (blk.*.ffn_*_exps.weight, ~100 GiB at
# Q8_0), read once per token; the CPU backend computes them from page
# cache.
# * per_layer_token_embd.weight=CPU — the 51.2B-element PLE n-gram table
# (dims [160, 320001536], Q8_0, 54.4 GiB — the whole of part 3):
# sparse row lookups, tiny PCIe traffic from CPU RAM. It doubles as
# the shared MTP head's borrow tensor — GPU-resident, the draft load
# crashes with "invalid vector subscript" (llama.cpp PR #28243) — so
# this override is REQUIRED, not just a placement choice. NEVER give
# it a GPU target (the 23 -> 13.4 t/s regression) and never --no-mmap
# (the table must stay page-cache-backed; anonymous memory
# cgroup-kills silently).
NGL=999
OT_OVERRIDES=exps=CPU,ngram_embeddings=CPU,per_layer_token_embd.weight=CPU
OT_OVERRIDES=exps=CPU,per_layer_token_embd.weight=CPU
TENSOR_SPLIT=1,1
# The drafter lives on the first R9700 (the card the load log shows holding
+1 -1
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@@ -50,7 +50,7 @@ fi
: "${PARALLEL_SLOTS:=1}"
: "${SPEC_DRAFT_N_MAX:=2}"
: "${NGL:=999}"
: "${OT_OVERRIDES:=exps=CPU,ngram_embeddings=CPU,per_layer_token_embd.weight=CPU}"
: "${OT_OVERRIDES:=exps=CPU,per_layer_token_embd.weight=CPU}"
: "${TENSOR_SPLIT:=1,1}"
: "${SPEC_DRAFT_DEVICE:=ROCm0}"
: "${BATCH_SIZE:=8192}"