Ubuntu 18.04 systemd-udevd使用高CPU，与wifi冲突
我最近从Kubuntu 17.10切换到Kubuntu 18.04（全新安装）。 问题是进程systemd-udevd不断运行并消耗90-100％的CPU负载。 在修补所有设备后，我发现它是因为WiFi！ 一旦我打开WiFi，进程就开始运行，CPU负载上升到100％。 但每当我关闭WiFi，它就会降到零！ 这是WiFi开启时的top结果：
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 338 root 20 0 94336 51744 3120 S 44.7 0.6 0:35.50 systemd-udevd 24957 root 20 0 67936 25248 2860 R 40.4 0.3 0:23.85 systemd-udevd 328 root 19 -1 150720 53068 52264 S 4.3 0.7 0:07.61 systemd-journal
并运行： strace -p 338重复输出以下内容：
strace: Process 338 attached strace: [ Process PID=338 runs in x32 mode. ] strace: [ Process PID=338 runs in 64 bit mode. ] epoll_wait(10, [{EPOLLIN, {u32=4010170080, u64=94544830289632}}, {EPOLLIN, {u32=4010060672, u64=94544830180224}}], 11, 0) = 2 clock_gettime(CLOCK_REALTIME, {tv_sec=1524848329, tv_nsec=484799898}) = 0 clock_gettime(CLOCK_MONOTONIC, {tv_sec=1045, tv_nsec=112300760}) = 0 clock_gettime(CLOCK_BOOTTIME, {tv_sec=1045, tv_nsec=112454363}) = 0 epoll_wait(10, [{EPOLLIN, {u32=4010170080, u64=94544830289632}}, {EPOLLIN, {u32=4010060672, u64=94544830180224}}], 11, 0) = 2 clock_gettime(CLOCK_REALTIME, {tv_sec=1524848329, tv_nsec=485376240}) = 0 clock_gettime(CLOCK_MONOTONIC, {tv_sec=1045, tv_nsec=112893238}) = 0 clock_gettime(CLOCK_BOOTTIME, {tv_sec=1045, tv_nsec=113047679}) = 0 recvmsg(7, {msg_name=NULL, msg_namelen=0, msg_iov=[{iov_base="", iov_len=0}], msg_iovlen=1, msg_control=[{cmsg_len=28, cmsg_level=SOL_SOCKET, cmsg_type=SCM_CREDENTIALS, cmsg_data={pid=24957, uid=0, gid=0}}], msg_controllen=32, msg_flags=0}, MSG_DONTWAIT) = 0 recvmsg(7, {msg_namelen=0}, MSG_DONTWAIT) = -1 EAGAIN (Resource temporarily unavailable) sendmsg(3, {msg_name={sa_family=AF_NETLINK, nl_pid=-853365251, nl_groups=00000000}, msg_namelen=12, msg_iov=[{iov_base="libudev\0\376\355\312\376(\0\0\0(\0\0\0\315\0\0\0\5w\305\345\261\2Ge"..., iov_len=40}, {iov_base="ACTION=unbind\0DEVPATH=/devices/p"..., iov_len=205}], msg_iovlen=2, msg_controllen=0, msg_flags=0}, 0) = 245 epoll_wait(10, [{EPOLLIN, {u32=4010170080, u64=94544830289632}}], 11, 0) = 1 clock_gettime(CLOCK_REALTIME, {tv_sec=1524848329, tv_nsec=495431807}) = 0 clock_gettime(CLOCK_MONOTONIC, {tv_sec=1045, tv_nsec=123814890}) = 0 clock_gettime(CLOCK_BOOTTIME, {tv_sec=1045, tv_nsec=123945023}) = 0 recvmsg(3, {msg_name={sa_family=AF_NETLINK, nl_pid=0, nl_groups=0x000001}, msg_namelen=128->12, msg_iov=[{iov_base="unbind@/devices/pci0000:00/0000:"..., iov_len=8192}], msg_iovlen=1, msg_control=[{cmsg_len=28, cmsg_level=SOL_SOCKET, cmsg_type=SCM_CREDENTIALS, cmsg_data={pid=0, uid=0, gid=0}}], msg_controllen=32, msg_flags=0}, 0) = 243 getrandom("\x9c\x6d\x41\x2b\xb5\xf0\xf1\x9a\x32\xb3\x4a\x73\xee\x04\xff\x90", 16, GRND_NONBLOCK) = 16 clock_gettime(CLOCK_MONOTONIC, {tv_sec=1045, tv_nsec=126971116}) = 0 getrandom("\xaf\x35\x7a\x36\x01\x32\xa6\xe6\x13\x46\x4e\x22\xcc\x48\x77\x9b", 16, GRND_NONBLOCK) = 16 getrandom("\x48\x0b\xeb\xf1\xf0\x1c\xf1\x78\x89\xb7\x48\xe1\x84\x38\xc9\x3c", 16, GRND_NONBLOCK) = 16 getrandom("\x11\x06\x8c\x4a\xeb\xff\x84\x8e\x0c\x09\x00\x84\x62\x74\xfc\xd7", 16, GRND_NONBLOCK) = 16 getrandom("\xb5\x8e\x19\x16\xad\xf6\x16\x7e\x21\x66\x90\x12\x2d\x43\x46\x45", 16, GRND_NONBLOCK) = 16 getrandom("\x84\x7d\x47\x96\x50\x36\xad\x28\x06\x6e\xed\x33\xe0\x05\x57\x20", 16, GRND_NONBLOCK) = 16 epoll_wait(10, [{EPOLLIN, {u32=4010170080, u64=94544830289632}}, {EPOLLIN, {u32=4010060672, u64=94544830180224}}], 11, 0) = 2 clock_gettime(CLOCK_REALTIME, {tv_sec=1524848329, tv_nsec=504542288}) = 0 clock_gettime(CLOCK_MONOTONIC, {tv_sec=1045, tv_nsec=131992368}) = 0 clock_gettime(CLOCK_BOOTTIME, {tv_sec=1045, tv_nsec=132096027}) = 0 epoll_wait(10, [{EPOLLIN, {u32=4010170080, u64=94544830289632}}, {EPOLLIN, {u32=4010060672, u64=94544830180224}}], 11, 0) = 2 clock_gettime(CLOCK_REALTIME, {tv_sec=1524848329, tv_nsec=504955877}) = 0 clock_gettime(CLOCK_MONOTONIC, {tv_sec=1045, tv_nsec=132438717}) = 0 clock_gettime(CLOCK_BOOTTIME, {tv_sec=1045, tv_nsec=132555928}) = 0 recvmsg(7, {msg_name=NULL, msg_namelen=0, msg_iov=[{iov_base="", iov_len=0}], msg_iovlen=1, msg_control=[{cmsg_len=28, cmsg_level=SOL_SOCKET, cmsg_type=SCM_CREDENTIALS, cmsg_data={pid=24957, uid=0, gid=0}}], msg_controllen=32, msg_flags=0}, MSG_DONTWAIT) = 0 recvmsg(7, {msg_namelen=0}, MSG_DONTWAIT) = -1 EAGAIN (Resource temporarily unavailable) sendmsg(3, {msg_name={sa_family=AF_NETLINK, nl_pid=-853365251, nl_groups=00000000}, msg_namelen=12, msg_iov=[{iov_base="libudev\0\376\355\312\376(\0\0\0(\0\0\0\23\1\0\0\5w\305\345\261\2Ge"..., iov_len=40}, {iov_base="ACTION=bind\0DEVPATH=/devices/pci"..., iov_len=275}], msg_iovlen=2, msg_controllen=0, msg_flags=0}, 0) = 315 epoll_wait(10, [{EPOLLIN, {u32=4010170080, u64=94544830289632}}], 11, 0) = 1 clock_gettime(CLOCK_REALTIME, {tv_sec=1524848329, tv_nsec=512870505}) = 0 clock_gettime(CLOCK_MONOTONIC, {tv_sec=1045, tv_nsec=140367037}) = 0 clock_gettime(CLOCK_BOOTTIME, {tv_sec=1045, tv_nsec=140494166}) = 0 recvmsg(3, {msg_name={sa_family=AF_NETLINK, nl_pid=0, nl_groups=0x000001}, msg_namelen=128->12, msg_iov=[{iov_base="bind@/devices/pci0000:00/0000:00"..., iov_len=8192}], msg_iovlen=1, msg_control=[{cmsg_len=28, cmsg_level=SOL_SOCKET, cmsg_type=SCM_CREDENTIALS, cmsg_data={pid=0, uid=0, gid=0}}], msg_controllen=32, msg_flags=0}, 0) = 311 getrandom("\x21\xcd\x52\xae\x20\xa4\xe9\x0f\x2c\x3f\x68\x8a\x77\x65\xfb\x22", 16, GRND_NONBLOCK) = 16 getrandom("\xb5\x1f\x43\xf7\x14\x3e\x29\x6c\xdd\x95\xd5\x64\xec\xec\x66\xca", 16, GRND_NONBLOCK) = 16 clock_gettime(CLOCK_MONOTONIC, {tv_sec=1045, tv_nsec=141295429}) = 0 getrandom("\xe7\x73\x2e\xc2\x5d\x71\x93\x8a\xd0\xf4\x5f\xd7\x91\x1f\x7b\x00", 16, GRND_NONBLOCK) = 16 getrandom("\xe4\xd4\xd3\x2c\xa2\xa1\x0c\x96\x6e\x6a\x34\x9c\x50\x06\x3d\x43", 16, GRND_NONBLOCK) = 16 getrandom("\xb0\x7f\xf7\x93\x1f\xa6\x6d\x2e\x01\xfb\x21\x97\x4b\xe8\x85\x14", 16, GRND_NONBLOCK) = 16 getrandom("\x3f\x94\x2b\x17\x01\x8f\x88\x2e\x08\xa0\x9d\xd0\xef\x4f\x0e\x9a", 16, GRND_NONBLOCK) = 16 epoll_wait(10, [{EPOLLIN, {u32=4010170080, u64=94544830289632}}, {EPOLLIN, {u32=4010060672, u64=94544830180224}}], 11, 0) = 2 clock_gettime(CLOCK_REALTIME, {tv_sec=1524848329, tv_nsec=519062044}) = 0 clock_gettime(CLOCK_MONOTONIC, {tv_sec=1045, tv_nsec=146474265}) = 0 clock_gettime(CLOCK_BOOTTIME, {tv_sec=1045, tv_nsec=146513033}) = 0 epoll_wait(10, [{EPOLLIN, {u32=4010170080, u64=94544830289632}}, {EPOLLIN, {u32=4010060672, u64=94544830180224}}], 11, 0) = 2 clock_gettime(CLOCK_REALTIME, {tv_sec=1524848329, tv_nsec=519231922}) = 0 clock_gettime(CLOCK_MONOTONIC, {tv_sec=1045, tv_nsec=146636530}) = 0 clock_gettime(CLOCK_BOOTTIME, {tv_sec=1045, tv_nsec=146675297}) = 0 recvmsg(7, {msg_name=NULL, msg_namelen=0, msg_iov=[{iov_base="", iov_len=0}], msg_iovlen=1, msg_control=[{cmsg_len=28, cmsg_level=SOL_SOCKET, cmsg_type=SCM_CREDENTIALS, cmsg_data={pid=24957, uid=0, gid=0}}], msg_controllen=32, msg_flags=0}, MSG_DONTWAIT) = 0 recvmsg(7, {msg_namelen=0}, MSG_DONTWAIT) = -1 EAGAIN (Resource temporarily unavailable) sendmsg(3, {msg_name={sa_family=AF_NETLINK, nl_pid=-853365251, nl_groups=00000000}, msg_namelen=12, msg_iov=[{iov_base="libudev\0\376\355\312\376(\0\0\0(\0\0\0\315\0\0\0\5w\305\345\261\2Ge"..., iov_len=40}, {iov_base="ACTION=unbind\0DEVPATH=/devices/p"..., iov_len=205}], msg_iovlen=2, msg_controllen=0, msg_flags=0}, 0) = 245 epoll_wait(10, [{EPOLLIN, {u32=4010170080, u64=94544830289632}}], 11, 0) = 1 clock_gettime(CLOCK_REALTIME, {tv_sec=1524848329, tv_nsec=525080911}) = 0 clock_gettime(CLOCK_MONOTONIC, {tv_sec=1045, tv_nsec=152528058}) = 0 clock_gettime(CLOCK_BOOTTIME, {tv_sec=1045, tv_nsec=152611810}) = 0 ....
运行udevadm monitor反复打印以下内容：
KERNEL[1464.842652] bind /devices/pci0000:00/0000:00:1a.0/usb3/3-1/3-1.2/3-1.2:1.0 (usb) KERNEL[1464.844393] unbind /devices/pci0000:00/0000:00:1a.0/usb3/3-1/3-1.2/3-1.2:1.0 (usb) UDEV [1464.845340] bind /devices/pci0000:00/0000:00:1a.0/usb3/3-1/3-1.2/3-1.2:1.0 (usb) KERNEL[1464.857728] bind /devices/pci0000:00/0000:00:1a.0/usb3/3-1/3-1.2/3-1.2:1.0 (usb) KERNEL[1464.858361] unbind /devices/pci0000:00/0000:00:1a.0/usb3/3-1/3-1.2/3-1.2:1.0 (usb) ....
并运行journalctl重复返回：
Apr 27 05:22:09 amir-pc systemd-udevd[359]: Process 'hid2hci --method=dell --devpath=/devices/pci0000:00/0000:00:1a.0/usb3/3-1/3-1.2/3 Apr 27 05:22:09 amir-pc upowerd[1339]: unhandled action 'unbind' on /sys/devices/pci0000:00/0000:00:1a.0/usb3/3-1/3-1.2/3-1.2:1.0 -- Logs begin at Fri 2018-04-27 05:22:09 +0430, end at Fri 2018-04-27 21:37:15 +0430. -- Apr 27 05:22:09 amir-pc systemd-udevd[359]: Process 'hid2hci --method=dell --devpath=/devices/pci0000:00/0000:00:1a.0/usb3/3-1/3-1.2/3 Apr 27 05:22:09 amir-pc upowerd[1339]: unhandled action 'unbind' on /sys/devices/pci0000:00/0000:00:1a.0/usb3/3-1/3-1.2/3-1.2:1.0 Apr 27 05:22:09 amir-pc systemd-udevd[359]: Process 'hid2hci --method=dell --devpath=/devices/pci0000:00/0000:00:1a.0/usb3/3-1/3-1.2/3 Apr 27 05:22:09 amir-pc upowerd[1339]: unhandled action 'bind' on /sys/devices/pci0000:00/0000:00:1a.0/usb3/3-1/3-1.2/3-1.2:1.0 ....
运行dmesg返回：
[ 441.582359] usb 3-1.3: New USB device strings: Mfr=1, Product=2, SerialNumber=0 [ 441.582361] usb 3-1.3: Product: Dell Wireless 370 Bluetooth Mini-card [ 441.582363] usb 3-1.3: Manufacturer: Dell Computer Corp [ 450.803644] usb 3-1.2: usbfs: USBDEVFS_CONTROL failed cmd hid2hci rqt 33 rq 9 len 4 ret -71 [ 450.811642] usb 3-1.2: usbfs: USBDEVFS_CONTROL failed cmd hid2hci rqt 33 rq 9 len 4 ret -71 [ 450.819653] usb 3-1.2: usbfs: USBDEVFS_CONTROL failed cmd hid2hci rqt 33 rq 9 len 4 ret -71 [ 450.826650] usb 3-1.2: usbfs: USBDEVFS_CONTROL failed cmd hid2hci rqt 33 rq 9 len 4 ret -71 [ 450.833668] usb 3-1.2: usbfs: USBDEVFS_CONTROL failed cmd hid2hci rqt 33 rq 9 len 4 ret -71 [ 450.841644] usb 3-1.2: usbfs: USBDEVFS_CONTROL failed cmd hid2hci rqt 33 rq 9 len 4 ret -71 [ 450.848630] usb 3-1.2: usbfs: USBDEVFS_CONTROL failed cmd hid2hci rqt 33 rq 9 len 4 ret -71 [ 450.856628] usb 3-1.2: usbfs: USBDEVFS_CONTROL failed cmd hid2hci rqt 33 rq 9 len 4 ret -71 [ 450.863632] usb 3-1.2: usbfs: USBDEVFS_CONTROL failed cmd hid2hci rqt 33 rq 9 len 4 ret -71 [ 450.871611] usb 3-1.2: usbfs: USBDEVFS_CONTROL failed cmd hid2hci rqt 33 rq 9 len 4 ret -71 [ 450.881629] usb 3-1.2: usbfs: USBDEVFS_CONTROL failed cmd hid2hci rqt 33 rq 9 len 4 ret -71 [ 450.888616] usb 3-1.2: usbfs: USBDEVFS_CONTROL failed cmd hid2hci rqt 33 rq 9 len 4 ret -71 [ 450.896634] usb 3-1.2: usbfs: USBDEVFS_CONTROL failed cmd hid2hci rqt 33 rq 9 len 4 ret -71 [ 450.903596] usb 3-1.2: usbfs: USBDEVFS_CONTROL failed cmd hid2hci rqt 33 rq 9 len 4 ret -71 [ 450.910611] usb 3-1.2: usbfs: USBDEVFS_CONTROL failed cmd hid2hci rqt 33 rq 9 len 4 ret -71 [ 450.917595] usb 3-1.2: usbfs: USBDEVFS_CONTROL failed cmd hid2hci rqt 33 rq 9 len 4 ret -71 [ 450.926603] usb 3-1.2: usbfs: USBDEVFS_CONTROL failed cmd hid2hci rqt 33 rq 9 len 4 ret -71 [ 450.933598] usb 3-1.2: usbfs: USBDEVFS_CONTROL failed cmd hid2hci rqt 33 rq 9 len 4 ret -71 [ 450.942616] usb 3-1.2: usbfs: USBDEVFS_CONTROL failed cmd hid2hci rqt 33 rq 9 len 4 ret -71 [ 450.949606] usb 3-1.2: usbfs: USBDEVFS_CONTROL failed cmd hid2hci rqt 33 rq 9 len 4 ret -71 [ 450.957363] usb 3-1.2: usbfs: USBDEVFS_CONTROL failed cmd hid2hci rqt 33 rq 9 len 4 ret -71 [ 450.964607] usb 3-1.2: usbfs: USBDEVFS_CONTROL failed cmd hid2hci rqt 33 rq 9 len 4 ret -71 [ 450.973581] usb 3-1.2: usbfs: USBDEVFS_CONTROL failed cmd hid2hci rqt 33 rq 9 len 4 ret -71 [ 450.980582] usb 3-1.2: usbfs: USBDEVFS_CONTROL failed cmd hid2hci rqt 33 rq 9 len 4 ret -71 [ 450.987582] usb 3-1.2: usbfs: USBDEVFS_CONTROL failed cmd hid2hci rqt 33 rq 9 len 4 ret -71 [ 450.994561] usb 3-1.2: usbfs: USBDEVFS_CONTROL failed cmd hid2hci rqt 33 rq 9 len 4 ret -71 [ 451.004574] usb 3-1.2: usbfs: USBDEVFS_CONTROL failed cmd hid2hci rqt 33 rq 9 len 4 ret -71 [ 451.009525] ERROR @wl_cfg80211_scan : [ 451.009527] WLC_SCAN error (-22) [ 451.010550] usb 3-1.2: usbfs: USBDEVFS_CONTROL failed cmd hid2hci rqt 33 rq 9 len 4 ret -71 [ 451.020078] usb 3-1: USB disconnect, device number 14 [ 451.020081] usb 3-1.1: USB disconnect, device number 15 [ 451.076974] usb 3-1.2: USB disconnect, device number 16 [ 451.077105] usb 3-1.3: USB disconnect, device number 19 [ 796.468102] usb 3-1: new full-speed USB device number 20 using uhci_hcd [ 796.672318] usb 3-1: New USB device found, idVendor=0a5c, idProduct=4500 [ 796.672322] usb 3-1: New USB device strings: Mfr=1, Product=2, SerialNumber=0 [ 796.672325] usb 3-1: Product: BCM2046B1 [ 796.672328] usb 3-1: Manufacturer: Broadcom [ 796.674239] hub 3-1:1.0: USB hub found [ 796.676385] hub 3-1:1.0: 3 ports detected [ 796.976059] usb 3-1.1: new full-speed USB device number 21 using uhci_hcd [ 797.109323] usb 3-1.1: New USB device found, idVendor=413c, idProduct=8157 [ 797.109332] usb 3-1.1: New USB device strings: Mfr=0, Product=0, SerialNumber=0 [ 797.116785] input: HID 413c:8157 as /devices/pci0000:00/0000:00:1a.0/usb3/3-1/3-1.1/3-1.1:1.0/0003:413C:8157.000B/input/input25 [ 797.176461] hid-generic 0003:413C:8157.000B: input,hidraw0: USB HID v1.11 Keyboard [HID 413c:8157] on usb-0000:00:1a.0-1.1/input0 [ 797.256314] usb 3-1.2: new full-speed USB device number 22 using uhci_hcd [ 797.396307] usb 3-1.2: New USB device found, idVendor=413c, idProduct=8158 [ 797.396315] usb 3-1.2: New USB device strings: Mfr=0, Product=0, SerialNumber=0 [ 797.405072] input: HID 413c:8158 as /devices/pci0000:00/0000:00:1a.0/usb3/3-1/3-1.2/3-1.2:1.0/0003:413C:8158.000C/input/input26 [ 797.464858] hid-generic 0003:413C:8158.000C: input,hidraw3: USB HID v1.11 Mouse [HID 413c:8158] on usb-0000:00:1a.0-1.2/input0 [ 797.564507] IPv6: ADDRCONF(NETDEV_UP): wlp4s0: link is not ready [ 797.944045] usb 3-1.3: new full-speed USB device number 23 using uhci_hcd [ 803.296508] usb 3-1.3: unable to read config index 0 descriptor/all [ 803.296515] usb 3-1.3: can't read configurations, error -110 [ 803.376039] usb 3-1.3: new full-speed USB device number 24 using uhci_hcd [ 808.672986] usb 3-1.3: unable to read config index 0 descriptor/all [ 808.672993] usb 3-1.3: can't read configurations, error -110 [ 808.673984] usb 3-1-port3: attempt power cycle [ 809.280029] usb 3-1.3: new full-speed USB device number 25 using uhci_hcd [ 809.340944] usb 3-1.3: New USB device found, idVendor=413c, idProduct=8156 [ 809.340948] usb 3-1.3: New USB device strings: Mfr=1, Product=2, SerialNumber=0 [ 809.340951] usb 3-1.3: Product: Dell Wireless 370 Bluetooth Mini-card [ 809.340954] usb 3-1.3: Manufacturer: Dell Computer Corp [ 1337.985097] perf: interrupt took too long (2508 > 2500), lowering kernel.perf_event_max_sample_rate to 79500 [ 1387.269440] perf: interrupt took too long (3140 > 3135), lowering kernel.perf_event_max_sample_rate to 63500 [ 1454.553305] perf: interrupt took too long (3927 > 3925), lowering kernel.perf_event_max_sample_rate to 50750 ....
并运行/lib/systemd/systemd-udevd -D重复返回以下结果：
IMPORT builtin 'hwdb' /lib/udev/rules.d/50-udev-default.rules:14 RUN 'hid2hci --method=dell --devpath=%p' /lib/udev/rules.d/97-hid2hci.rules:11 starting 'hid2hci --method=dell --devpath=/devices/pci0000:00/0000:00:1a.0/usb3/3-1/3-1.2/3-1.2:1.0' seq 284188 queued, 'bind' 'usb' seq 284189 queued, 'unbind' 'usb' 'hid2hci --method=dell --devpath=/devices/pci0000:00/0000:00:1a.0/usb3/3-1/3-1.2/3-1.2:1.0'(err) 'error: switching device '/sys//devices/pci0000:00/0000:00:1a.0/usb3/3-1/3-1.2/3-1.2:1.0' failed.' Process 'hid2hci --method=dell --devpath=/devices/pci0000:00/0000:00:1a.0/usb3/3-1/3-1.2/3-1.2:1.0' failed with exit code 1. seq 284184 processed seq 284185 running RUN 'hid2hci --method=dell --devpath=%p' /lib/udev/rules.d/97-hid2hci.rules:11 starting 'hid2hci --method=dell --devpath=/devices/pci0000:00/0000:00:1a.0/usb3/3-1/3-1.2/3-1.2:1.0' seq 284190 queued, 'bind' 'usb' seq 284191 queued, 'unbind' 'usb'
我新安装的Kubuntu使用内核版本4.15.0-20-generic ，我的笔记本电脑是戴尔Studio XPS bcmwl-kernel-source 6.30.223.271+bdcom-0ubuntu4使用bcmwl-kernel-source 6.30.223.271+bdcom-0ubuntu4驱动程序（降级到以前工作的驱动程序没有’解决问题）。
值得一提的是，没有USB设备连接，只有无线鼠标，这没有问题（断开它不会影响问题）。 但如上所述，关闭WiFi总是会使高CPU负载消失。
我在戴尔XPS Studio 1340上安装了Ubuntu 18.04 LTS（AMD64），我遇到了同样的问题。 我已经通过 从BIOS完全禁用蓝牙 解决了这个问题 。 我知道这不是一个解决方案，而是一种解决方法，但它对我有用，因为我很少使用蓝牙。
它看起来像内核或systemd中的一个错误而没有修复：
- bugzilla.kernel.org上的错误报告主题
- Launchpad上的错误报告
我正在将dell studio 1737从Ubuntu 16.04升级到18.04，并找到了类似问题的答案。
我的系统已经很老了，在关机之前不能容忍100％的CPU超过几分钟，所以我还没有看到18.04的登录屏幕。 这是一个艰难的过程！
ctrl + alt + f2给了我一个终端登录， top显示systemd-udevd是100％CPU。
less /var/log/syslog
显示
Process 'hid2hci --method=dell failed
一遍又一遍地。
hid2hci是一个蓝牙过程，BT不是我需要的东西，它被禁用了。 好奇。
我的直接目标是更长时间访问此计算机。 毫无疑问，专家最终会提出正确的解决方案，但我在Manjaro论坛上发现了这篇文章
我发现移除
/lib/udev/rules.d/97-hid2hci.rules（由bluez包提供）之后问题就消失了。他们在那里提到的设备包括戴尔触摸板…我不知道触摸板与什么有关蓝牙或为什么bluez正在配置它们。
所以我/lib/udev/rules.d/97-hid2hci.rules …重新启动后， sytemd-udevd现在表现良好。
这只能被认为是一种临时解决方案，而且我不知道这种变化是否会对wifi或触摸板产生影响（我既不使用），也不会产生其他问题，但我处于比以往更多的位置几个小时前！
在我的情况下，这个问题是由于bluez。 打开Synaptic包管理器并搜索bluez，然后将其卸载。 你的问题将得到解决。
如前面的答案所述，它与戴尔无线370蓝牙并不是最好的相关，而且我的戴尔Studio XPS 1645也受到了影响。
不仅蓝牙支持已经运行了几年，现在内核驱动程序中存在影响CPU使用率的新问题。
我只想添加，而不是删除/lib/udev/rules.d/97-hid2hci.rules文件，而不是创建一个空文件：
touch /etc/udev/rules.d/97-hid2hci.rules
这将保证在bluez包更新后不再出现问题。
另外，我已经完成了在ebay上购买一两个蓝牙加密狗，但我宁愿让笔记本电脑按预期运行，当然。
这是一个解决方法：
启动后立即运行以下命令：
sudo systemctl stop systemd-udevd systemd-udevd-kernel.socket systemd-udevd-control.socket sudo systemctl start systemd-udevd systemd-udevd-kernel.socket systemd-udevd-control.socket
它适用于我的戴尔笔记本电脑。
您设备或任何设备上的蓝牙应用程序与您的手机完全相同，您必须先安装第三方应用程序或升级处理蓝牙设备的应用程序bluez …因此重启后它会触发蓝牙软件发现任何范围内的蓝牙设备，没有找到，所以它重申…至少在我看来，它似乎遵循这个确切的程序 。
由于这条线，您的WiFifunction达到了100％
Dell Wireless 370 Bluetooth
Bluez应用程序正在搜索一个可能消耗更多内存和处理的无线驱动程序。 我相信你已经解决了这个问题; 很好！
正如您所看到的USB设备文件系统控制的USB文件系统因为没有响应而失败，该命令正在使用（cmd）
Android和IOS应用程序隐藏了您的video和图像，称为keepsafe（hid）与人机交互（hci），而rqt是ROS的软件框架，用于管理屏幕上的各种窗口。
[450.803644] usb 3-1.2：usbfs：USBDEVFS_CONTROL失败cmd hid2hci rqt 33 rq 9 len 4 ret -71
我想我已经找到了答案。
跑
/lib/systemd/systemd-udevd -D
应该在包含“… / 97-hid2hci.rules：”的无限循环中打印垃圾
如果是这样，请编辑/lib/udev/rules.d/97-hid2hci.rules
并添加
ACTION=="add"
在上面命令提到的行前面。
它应该是这样的（我使用Fedora 28，但问题看起来相同）：
ACTION=="add", ATTR{bInterfaceClass}=="03", ATTR{bInterfaceSubClass}=="01", ATTR{bInterfaceProtocol}=="02", \ ATTRS{bDeviceClass}=="00", ATTRS{idVendor}=="413c", ATTRS{bmAttributes}=="e0", \ RUN+="hid2hci --method=dell --devpath=%p", ENV{HID2HCI_SWITCH}="1"
通过以上修复，一切都在我的旧戴尔上完美无缺。 希望有所帮助;）