| name | training_hang |
| description | Training stalled — capture stacks and thread/blocking hints
|
| category | reliability |
| tables | ["python.backtrace","cpu.utilization","python.trace_event","python.comm_collective"] |
| tags | ["hang","stall","deadlock","卡住","不动"] |
| keywords | {"en":["hang","stuck","stall","frozen","deadlock","not progressing"],"zh":["卡住","hang","不动","停住","deadlock","死锁","loss 不更新"]} |
| parameters | {"stack_depth":{"type":"integer","default":20}} |
Training hang diagnosis
Loss 不更新、进程仍存活但无进展时使用。
组合:实时混合栈 + CPU 线程 wchan + 最近 trace 活动。
Parameters
stack_depth (integer, default 20): Backtrace frames to show
Related skills
- 栈在 dist/barrier → 检查各 rank 是否都存活: probing list / cluster nodes
- 栈在 DataLoader → 减少 num_workers 或检查数据路径
- 需要持续采样 → SET probing.pprof.sample_freq=99 后 skill: module_bottleneck