Recientemente cambié de Kubuntu 17.10 a Kubuntu 18.04 (recién instalado). El problema es que el proceso systemd-udevd
se ejecuta constantemente y consume 90-100% de carga de CPU. Después de jugar con todos los dispositivos, descubrí que se debe a WiFi. Una vez que enciendo WiFi, el proceso comienza a ejecutarse y la carga de la CPU sube al 100%. ¡Pero cada vez que apago el WiFi se pone a cero! Estos son los top
resultados cuando WiFi está encendido:
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
y en ejecución: strace -p 338
realiza el siguiente resultado repetidamente:
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
....
corriendo udevadm monitor
imprime lo siguiente repetidamente:
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)
....
y corriendo journalctl
vuelve repetidamente:
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
....
ejecutando dmesg
devoluciones:
[ 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
....
y ejecuta /lib/systemd/systemd-udevd -D
retornos debajo de los resultados repetidamente:
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'
Mi Kubuntu recién instalado está usando la versión del kernel 4.15.0-20-generic
y mi computadora portátil es una Dell Studio XPS 1640. WiFi está usando el bcmwl-kernel-source 6.30.223.271+bdcom-0ubuntu4
controlador (la degradación a un controlador anterior no resolvió el problema).
Vale la pena mencionar que no hay dispositivos USB conectados, solo un mouse inalámbrico, lo que no hace ningún problema (desconectarlo no afecta el problema). Pero como se mencionó, apagar el WiFi siempre hace desaparecer la alta carga de CPU.