cpu 占用较高，但是占用 最高线程的threadID 为 -1 ，为 vm thread ，但是无法查看线程运行详情

Nobody has claimed this yet.

- [ ] 我已经在 [issues](https://github.com/alibaba/arthas/issues) 里搜索，没有重复的issue。

### 环境信息

* `arthas-boot.jar` 或者 `as.sh` 的版本： xxx
* Arthas 版本: xxx
* 操作系统版本: xxx
* 目标进程的JVM版本: xxx
* 执行`arthas-boot`的版本: xxx

### 重现问题的步骤

1. xxx
2. xxx
3. xxx

### 期望的结果

What do you expected from the above steps？

### 实际运行的结果

实际运行结果，最好有详细的日志，异常栈。尽量贴文本。

```
把异常信息贴到这里
```

The report does not identify a source file, command, Arthas version, JVM, operating system, reproduction steps, logs, or expected behavior. Start by collecting the missing environment and reproduction details, then trace how Arthas reports a highest-CPU thread with threadID -1. Done requires a reproducible diagnosis and a defined way to inspect that VM thread's running details.

Written by the indexing model from the issue text.