Files
emilandClaude Opus 4.7 ee8a9fc5bc Fix cross-process recall: MEMB trailer + raw eval/sample in chat()
Two bugs were blocking memba's main promise (load .memb in a fresh
process → model continues with full recalled context):

1. llama_state_set_data() restores the C-level KV-cache + SSM hidden
   state, but llama-cpp-python's Python wrapper still reports
   n_tokens=0. The next eval() then decodes new tokens at offset 0
   and overwrites the loaded state.

   Fix: extend MEMB format with an optional 12-byte trailer appended
   after the CRC32. It carries the wrapper's n_tokens. The C library
   reads up to CRC and ignores anything past it, so files stay
   backward-compatible with libmemba; only the Python loader uses it.

2. Llama.__call__ / create_chat_completion / generate all re-tokenise
   the prompt on every call and clear the KV-cache when the new
   tokens don't prefix-match input_ids. That destroys any state we
   just loaded.

   Fix: rewrite Session.chat() to use raw tokenize → eval → sample.
   eval() appends tokens to the live state without resetting, and we
   handle stop-token detection ourselves.

Verified end-to-end on Nemotron-3-Nano-4B (hybrid 21x Mamba-2 + 4x
attention) — see experiments/README.md for the full findings log.
diag_session_nemotron.py, mood_batch_poc.py, mood_stream_poc.py and
recall_poc.py now all pass their cross-process tests; Falcon-Mamba
still fails because the trained model itself can't do cross-turn
recall — that was the original misdiagnosis.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
2026-05-16 13:18:31 +03:00

96 lines
3.4 KiB
Python

"""
diag_nemotron.py — hamster recall test on Nemotron 3 Nano 4B (hybrid Mamba-Transformer).
The Falcon-Mamba 0/4 hamster failure was the killshot for several product ideas.
This rerun tests whether the hybrid architecture (21 Mamba-2 layers + 4 attention)
fixes cross-turn recall.
Three scenarios are measured:
1. In-process multi-turn (tell fact, ask next turn)
2. Same process: save then ask after save
3. Cross process: build (ingest, save, exit), then query (load, ask)
Uses create_chat_completion which applies the GGUF's own chat template.
"""
from __future__ import annotations
import sys, argparse, time
from pathlib import Path
sys.path.insert(0, str(Path(__file__).resolve().parent.parent / "python"))
from llama_cpp import Llama
from memba import core
MODEL = "/home/emil/Desktop/Coding/AI/Memba/NVIDIA-Nemotron3-Nano-4B-Q4_K_M.gguf"
STATE = "/tmp/diag_nemotron.memb"
INGEST = ("I'm going to tell you a fact about my pet. My pet hamster is named "
"Bartholomew. He is 4 years old. Reply with just 'noted'.")
QUERY = "What is the name of my pet?"
def make_llama():
return Llama(model_path=MODEL, n_ctx=4096, n_gpu_layers=-1, verbose=False)
def chat_continued(m, messages):
"""Send accumulated chat history, return assistant text + cleaned (strip reasoning)."""
out = m.create_chat_completion(
messages=messages,
max_tokens=200,
temperature=0.1,
)
full = out["choices"][0]["message"]["content"].strip()
# Nemotron leaks reasoning — try to extract the final answer if present
short = full[-300:] if len(full) > 300 else full
return full, short
def build():
print(f"[build] loading Nemotron 4B…")
t0 = time.time()
m = make_llama()
print(f"[build] loaded in {time.time()-t0:.1f}s")
messages = [{"role": "user", "content": INGEST}]
full, _ = chat_continued(m, messages)
print(f"[build] ack (full):\n{full!r}\n")
messages.append({"role": "assistant", "content": full})
# Test 1: in-process recall WITHIN the same chat
messages.append({"role": "user", "content": QUERY})
full, short = chat_continued(m, messages)
print(f"[build] in-process query BEFORE save:\n{full}\n")
messages.append({"role": "assistant", "content": full})
# Save state at this point
core.save_state(m, MODEL, STATE)
print(f"[build] saved state ({Path(STATE).stat().st_size:,} B)")
# Test 2: in-process query AFTER save — should still work
messages.append({"role": "user", "content": QUERY})
full, _ = chat_continued(m, messages)
print(f"[build] in-process query AFTER save:\n{full}\n")
def query():
if not Path(STATE).exists():
print("[query] no state — run build first"); return 1
print(f"[query] loading model + state ({Path(STATE).stat().st_size:,} B)…")
t0 = time.time()
m = make_llama()
core.load_state(m, MODEL, STATE)
print(f"[query] loaded in {time.time()-t0:.1f}s")
# Cross-process: send a fresh user turn with only the question
# The state should already encode the prior conversation
out = m.create_chat_completion(
messages=[{"role": "user", "content": QUERY}],
max_tokens=200,
temperature=0.1,
)
print(f"[query] cross-process answer:\n{out['choices'][0]['message']['content']}")
if __name__ == "__main__":
cmd = sys.argv[1] if len(sys.argv) > 1 else "build"
{"build": build, "query": query}[cmd]()