Je suis récemment passé de Kubuntu 17.10 à Kubuntu 18.04 (fraîchement installé). Le problème est que le processus systemd-udevd
est en cours d'exécution et consomme 90 à 100% de charge CPU. Après avoir bricolé tous les appareils, j'ai découvert que c'était à cause du WiFi! Une fois que j'allume le WiFi, le processus démarre et la charge du processeur monte à 100%. Mais chaque fois que j'éteins le WiFi, il tombe à zéro! voici les top
résultats lorsque le WiFi est activé:
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
et en cours d'exécution: strace -p 338
effectue la sortie suivante à plusieurs reprises:
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
....
l'exécution udevadm monitor
imprime à plusieurs reprises les éléments suivants:
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)
....
et exécuter des journalctl
retours à plusieurs reprises:
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
....
dmesg
retours en cours :
[ 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
....
et en exécutant les /lib/systemd/systemd-udevd -D
résultats ci-dessous à plusieurs reprises:
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'
Mon nouveau Kubuntu installé utilise la version du noyau 4.15.0-20-generic
et mon ordinateur portable est un Dell Studio XPS 1640. Le WiFi utilise un bcmwl-kernel-source 6.30.223.271+bdcom-0ubuntu4
pilote (la rétrogradation vers un pilote fonctionnant précédent n'a pas résolu le problème).
Il convient de mentionner qu'aucun périphérique USB n'est connecté, uniquement une souris sans fil, ce qui ne pose aucun problème (sa déconnexion n'affecte pas le problème). Mais comme mentionné, la désactivation du WiFi fait toujours disparaître la charge élevée du processeur.