我对已失效的流程有些困惑。也就是说，为什么已失效的进程正在使用 CPU。我在 top 命令中吸收了已失效进程的 CPU 时间利用率。有时，已失效的进程占用超过 55 个 CPU 时间。但是，根据一些文档，已失效的进程不应使用 CPU。
PID TID CLS RTPRIO NI PRI PSR %CPU STAT WCHAN COMMAND
15304 15304 TS - 0 19 0 0.6 Z - My.pl <defunct>
15494 15494 TS - 0 19 7 0.4 Z - My.pl <defunct>
17075 17075 TS - 0 19 5 0.5 Z - My.pl <defunct>
17659 17659 TS - 0 19 2 0.6 Z - My.pl <defunct>
18118 18118 TS - 0 19 7 0.8 Z - My.pl <defunct>
18388 18388 TS - 0 19 4 1.1 Z - My.pl <defunct>
18520 18520 TS - 0 19 3 0.7 Z - My.pl <defunct>
18864 18864 TS - 0 19 3 0.7 Z - My.pl <defunct>
19291 19291 TS - 0 19 5 1.1 Z - My.pl <defunct>
19479 19479 TS - 0 19 3 1.0 Z - My.pl <defunct>
19544 19544 TS - 0 19 1 1.3 Z - My.pl <defunct>
19806 19806 TS - 0 19 6 1.1 Z - My.pl <defunct>
19809 19809 TS - 0 19 4 2.0 Z - My.pl <defunct>
20056 20056 TS - 0 19 7 1.3 Z - My.pl <defunct>
20577 20577 TS - 0 19 5 2.2 Z - My.pl <defunct>
22239 22239 TS - 0 19 4 6.9 Z - My.pl <defunct>
22246 22246 TS - 0 19 3 2.2 Z - My.pl <defunct>
22269 22269 TS - 0 19 7 2.1 Z - My.pl <defunct>
23337 23337 TS - 0 19 5 3.2 Z - My.pl <defunct>
23950 23950 TS - 0 19 4 7.2 Z - My.pl <defunct>
你能解释一下为什么失效的进程正在使用 CPU 吗？