Environment:
- Fedora 44
- Kernel: 7.1.8-200.fc44.x86_64
- Hardware: AMD Ryzen AI 7 PRO 350, RyzenAI-npu6 (6x8)
- FLM: 1.0.2
- XRT: 2.26.0
- amdxdna: 0.8
- NPU firmware: 1.1.2.64
Validation:
flm validate succeeds:
- /dev/accel/accel0 with 8 columns
- NPU firmware 1.1.2.64
- amdxdna 0.8
- memlock infinity
Repro:
flm run qwen3.5:4b
or
flm run qwen3.5:9b
Prompt:
hi
Actual result:
Both models load successfully, then print:
[FLM] Prefill chunk 1/1 with 13 tokens
and hang indefinitely. They never reach:
[FLM] Creating checkpoint at context length 13
The Qwen3.5 model directories were removed and downloaded again after FLM reported old Qwen models as incompatible.
Working controls on the exact same system:
- llama3.2:3b processes a 41-token prefill and replies correctly.
- qwen3.6-moe:35b-a3b passes prefill, creates a checkpoint, and replies correctly.
RAM is not exhausted:
- Qwen3.5 4B/9B uses roughly 45% RAM when hung.
- qwen3.6-moe:35b-a3b works despite RAM usage above 90%.
This appears specific to the Qwen3.5 prefill/runtime path in FLM 1.0.2 on Linux.
Environment:
Validation:
flm validate succeeds:
Repro:
flm run qwen3.5:4b
or
flm run qwen3.5:9b
Prompt:
hi
Actual result:
Both models load successfully, then print:
[FLM] Prefill chunk 1/1 with 13 tokens
and hang indefinitely. They never reach:
[FLM] Creating checkpoint at context length 13
The Qwen3.5 model directories were removed and downloaded again after FLM reported old Qwen models as incompatible.
Working controls on the exact same system:
RAM is not exhausted:
This appears specific to the Qwen3.5 prefill/runtime path in FLM 1.0.2 on Linux.