ubuntu 服务器上的 kworker 进程占用的 cpu 持续增加

服务器系统是 ubuntu 16.04 。kworker 进程表现明显异常。每次重启后正常，几天不重启，kworker 进程占用的 CPU 会持续上升。

服务器有 40 核 80 线程，只要计算任务稍高（但不会超过 50%的总利用率），这个 Kwork 进程的占用也会随之而上升。

比如下面是现在的占用，每个 kworker 进程要占到 15%到 20%的 CPU。

何解？

17759 root 20 0 0 0 0 S 22.2 0.0 0:50.88 kworker/30:2 9738 root 20 0 0 0 0 S 21.6 0.0 1:36.46 kworker/22:10 15727 root 20 0 0 0 0 S 20.7 0.0 0:50.71 kworker/35:0 4009 root 20 0 0 0 0 S 20.1 0.0 2:09.24 kworker/71:0 14877 root 20 0 0 0 0 S 20.1 0.0 0:45.04 kworker/23:1 15779 root 20 0 0 0 0 S 20.1 0.0 0:52.27 kworker/37:2 144257 root 20 0 0 0 0 S 20.1 0.0 2:49.50 kworker/69:2 13592 root 20 0 0 0 0 S 19.8 0.0 1:01.53 kworker/24:2 14997 root 20 0 0 0 0 S 19.8 0.0 0:48.79 kworker/76:2 18386 root 20 0 0 0 0 S 19.8 0.0 0:47.26 kworker/34:0 96270 root 20 0 0 0 0 S 19.2 0.0 3:20.43 kworker/73:0 16390 root 20 0 0 0 0 S 18.9 0.0 0:52.08 kworker/32:2 18698 root 20 0 0 0 0 S 18.9 0.0 0:49.32 kworker/14:0 22607 root 20 0 0 0 0 S 18.9 0.0 0:13.00 kworker/77:2 59163 zhangzq 20 0 32.109g 0.020t 0.020t S 18.9 16.2 15:40.76 tdf_dump 89994 root 20 0 0 0 0 S 18.6 0.0 3:54.33 kworker/75:1 5927 root 20 0 0 0 0 S 18.3 0.0 2:10.41 kworker/21:10 17499 root 20 0 0 0 0 S 18.0 0.0 0:49.03 kworker/31:1 87653 root 20 0 0 0 0 S 18.0 0.0 4:18.64 kworker/70:2 17668 root 20 0 0 0 0 S 17.7 0.0 0:50.40 kworker/18:0 20226 root 20 0 0 0 0 S 17.7 0.0 0:34.18 kworker/19:12 145927 root 20 0 0 0 0 S 17.7 0.0 3:06.14 kworker/26:2 18586 root 20 0 0 0 0 S 17.4 0.0 0:45.97 kworker/25:1 21019 root 20 0 0 0 0 S 17.4 0.0 0:19.63 kworker/63:12 15284 root 20 0 0 0 0 S 17.1 0.0 0:45.27 kworker/78:0 18076 root 20 0 0 0 0 S 17.1 0.0 0:49.19 kworker/12:2 18984 root 20 0 0 0 0 S 17.1 0.0 0:47.85 kworker/38:0 138840 root 20 0 0 0 0 S 16.8 0.0 2:29.14 kworker/51:1 18316 root 20 0 0 0 0 S 16.5 0.0 0:48.14 kworker/13:0 18341 root 20 0 0 0 0 S 16.5 0.0 0:51.44 kworker/11:1 19904 root 20 0 0 0 0 S 16.5 0.0 0:33.35 kworker/64:9 19985 root 20 0 0 0 0 S 16.5 0.0 0:38.51 kworker/33:0 22601 root 20 0 0 0 0 S 16.5 0.0 0:11.88 kworker/27:1 14430 root 20 0 0 0 0 S 16.3 0.0 0:56.02 kworker/36:1 20860 root 20 0 0 0 0 S 16.3 0.0 0:33.18 kworker/17:0 21420 root 20 0 0 0 0 S 16.3 0.0 0:22.05 kworker/15:17 17148 root 20 0 0 0 0 S 16.0 0.0 0:47.60 kworker/59:0 21443 root 20 0 0 0 0 S 16.0 0.0 0:19.03 kworker/29:2 66158 root 20 0 0 0 0 S 16.0 0.0 4:20.64 kworker/61:0 98647 root 20 0 0 0 0 S 16.0 0.0 3:23.56 kworker/66:0 111881 root 20 0 0 0 0 S 16.0 0.0 3:03.42 kworker/45:0 136391 root 20 0 0 0 0 S 16.0 0.0 2:41.38 kworker/72:2 447 root 20 0 0 0 0 S 15.7 0.0 1:05.69 kworker/20:5 146310 root 20 0 0 0 0 S 15.7 0.0 2:43.91 kworker/5:2 147091 root 20 0 0 0 0 S 15.7 0.0 2:56.16 kworker/60:9 3543 root 20 0 0 0 0 S 15.4 0.0 2:23.02 kworker/62:0 12254 root 20 0 0 0 0 S 15.4 0.0 1:01.56 kworker/79:0 16571 root 20 0 0 0 0 S 15.4 0.0 0:46.58 kworker/56:0 22211 root 20 0 0 0 0 S 15.1 0.0 0:18.21 kworker/50:10 17190 root 20 0 0 0 0 S 14.8 0.0 0:45.99 kworker/52:1 18794 root 20 0 0 0 0 S 14.8 0.0 0:46.80 kworker/39:0 112976 root 20 0 0 0 0 S 14.8 0.0 3:10.59 kworker/68:1