kworker 为外部硬盘驱动器消耗高 CPU

Question

kworker进程消耗一个 CPU 的 75%。有问题的kworker线程与 ACPI 的东西有关：

sudo cat /proc/THE_PID_OF_KWORKER_PROCESS/stack
[<ffffffff85c0c705>] acpi_ns_evaluate+0x1bc/0x23a
[<ffffffff85bffe09>] acpi_ev_asynch_execute_gpe_method+0x98/0xff
[<ffffffff85be4e30>] acpi_os_execute_deferred+0x10/0x20
[<ffffffff8588dc21>] process_one_work+0x181/0x370
[<ffffffff8588de5d>] worker_thread+0x4d/0x3a0
[<ffffffff85893f1c>] kthread+0xfc/0x130
[<ffffffff8588de10>] process_one_work+0x370/0x370
[<ffffffff85893e20>] kthread_create_on_node+0x70/0x70
[<ffffffff858791ba>] do_group_exit+0x3a/0xa0
[<ffffffff85e6a2b5>] ret_from_fork+0x25/0x30
[<ffffffffffffffff>] 0xffffffffffffffff

所以我通过使用一些与 acpi 相关的内核参数重新启动来开始调试，例如：

acpi=off : Completely solves the high cpu usage, but computer no longer suspends. 
acpi=ht : no effect, still high cpu usage
pci=noacpi : not booting at all
pnpacpi=off : no effect, still high cpu usage
noapic : worse, 100% cpu usage 
nolapic : worse, 100% cpu usage 

uname -a： Linux 4.13.0-1-amd64 #1 SMP Debian 4.13.4-1 (2017-10-01) x86_64 GNU/Linux

我的根文件夹磁盘布局是：BTRFSover LVMover LUKS。

我怎样才能找到问题的根源？

更新

我没有使用我的外部硬盘驱动器，它使用 DVD 外壳连接到笔记本电脑。

今天我重新连接了驱动器，kworker 再次消耗了过多的 CPU。请注意，我没有从外部驱动器挂载分区，只是附加导致了 CPU 使用率。

Answer 1

当我检查 ACPI 中断时，我注意到gpe6F触发计数非常高：

root@HOST:~# grep . -r /sys/firmware/acpi/interrupts/

/sys/firmware/acpi/interrupts/ff_gbl_lock: 0  EN     enabled      unmasked
/sys/firmware/acpi/interrupts/gpe15:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe4F:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe43:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe7D:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe71:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe05:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe3F:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe33:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe6D:       0         disabled     unmasked
/sys/firmware/acpi/interrupts/gpe61:       0  EN     enabled      unmasked
/sys/firmware/acpi/interrupts/gpe2F:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe23:       0  EN     enabled      unmasked
/sys/firmware/acpi/interrupts/gpe5D:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe51:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe1F:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe13:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe4D:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe41:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe7B:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe0F:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe03:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe3D:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe31:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe6B:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe2D:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe21:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe5B:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe1D:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe78:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe11:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe4B:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/ff_pwr_btn:  0  EN     enabled      unmasked
/sys/firmware/acpi/interrupts/ff_slp_btn:  0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe0D:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe68:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe01:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/ff_pmtimer:  0     STS invalid      unmasked
/sys/firmware/acpi/interrupts/gpe3B:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe58:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe2B:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe48:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe1B:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe76:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe38:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe0B:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe66:       4  EN     enabled      unmasked
/sys/firmware/acpi/interrupts/gpe28:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe56:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe18:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe46:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe74:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe08:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/sci:  819678
/sys/firmware/acpi/interrupts/gpe36:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe64:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe26:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/error:       0
/sys/firmware/acpi/interrupts/gpe54:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe16:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe44:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe7E:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe72:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe06:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/ff_rt_clk:             disabled     unmasked
/sys/firmware/acpi/interrupts/gpe34:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe6E:  262969  EN     enabled      unmasked
/sys/firmware/acpi/interrupts/gpe62:       0  EN     enabled      unmasked
/sys/firmware/acpi/interrupts/gpe24:       0  EN     enabled      unmasked
/sys/firmware/acpi/interrupts/gpe5E:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe52:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe14:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe4E:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe42:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe7C:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe70:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe04:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe3E:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe32:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe6C:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe60:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe2E:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe22:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe5C:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe50:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe1E:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe79:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe12:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe4C:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe40:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe7A:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe0E:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe69:       0         disabled     unmasked
/sys/firmware/acpi/interrupts/gpe02:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe3C:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe30:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe6A:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe59:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe2C:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe20:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe5A:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe49:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe1C:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe77:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe10:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe4A:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe39:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe0C:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe67:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe00:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe3A:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe29:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe57:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe2A:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe19:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe47:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe1A:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe75:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe09:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe37:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe0A:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe65:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe27:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe55:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe17:       0     STS invalid      unmasked
/sys/firmware/acpi/interrupts/gpe45:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe7F:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/sci_not:     101
/sys/firmware/acpi/interrupts/gpe73:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe07:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe35:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe6F:  560719     STS enabled      unmasked
/sys/firmware/acpi/interrupts/gpe63:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe25:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe5F:       0         invalid      unmasked
/sys/firmware/acpi/interrupts/gpe_all:  823692
/sys/firmware/acpi/interrupts/gpe53:       0         invalid      unmasked

我禁用了它：

root@HOST:~# echo "disable" > /sys/firmware/acpi/interrupts/gpe6F

一切恢复正常：

Linux 4.9.0-6-amd64 (HOST)  05/01/2018  _x86_64_    (4 CPU)

12:30:27 PM     CPU     %user     %nice   %system   %iowait    %steal     %idle
12:30:30 PM     all      6.88      0.00      1.26      0.17      0.00     91.69
12:30:33 PM     all      6.45      0.00      1.17      0.17      0.00     92.20
12:30:36 PM     all      7.15      0.00      1.01      0.34      0.00     91.51
Average:        all      6.83      0.00      1.15      0.22      0.00     91.80

Answer 2

显然这是一个与硬件相关的问题。kworker 进程与外部 HDD 外壳相关，其中外壳有一个可用于不同品牌的开关：

切换开关解决了这个问题。