Hallo,
ich habe seit dem letzten Update alle 2-3 sec einen sprunghaften Anstieg der CPU-Auslastung im Ruhezustand. htop zeigt keine Prozesse an, die für diese Beanspruchung verantwortlich sind. Ich bin ein wenig ratlos, da immer nur ein Kern ausgelastet wird.

Ein Downgrade des kernels hat nichts gebracht. Die vollständige Liste der aktualisierten Pakte:

[2013-04-13 17:55] [PACMAN] Running 'pacman -Syu'
[2013-04-13 17:55] [PACMAN] synchronizing package lists
[2013-04-13 17:55] [PACMAN] starting full system upgrade
[2013-04-13 18:03] [PACMAN] upgraded alsa-plugins (1.0.26-1 -> 1.0.27-1)
[2013-04-13 18:03] [ALPM-SCRIPTLET] Generating locales...
[2013-04-13 18:03] [ALPM-SCRIPTLET]   de_AT.UTF-8... done
[2013-04-13 18:03] [ALPM-SCRIPTLET]   de_AT.ISO-8859-1... done
[2013-04-13 18:03] [ALPM-SCRIPTLET]   de_AT.ISO-8859-15@euro... done
[2013-04-13 18:03] [ALPM-SCRIPTLET] Generation complete.
[2013-04-13 18:03] [PACMAN] upgraded glibc (2.17-4 -> 2.17-5)
[2013-04-13 18:03] [PACMAN] upgraded binutils (2.23.2-1 -> 2.23.2-2)
[2013-04-13 18:03] [PACMAN] upgraded libcap (2.22-3 -> 2.22-4)
[2013-04-13 18:03] [PACMAN] upgraded systemd (200-1 -> 201-1)
[2013-04-13 18:04] [PACMAN] upgraded chromium (26.0.1410.43-2 -> 26.0.1410.63-1)
[2013-04-13 18:04] [PACMAN] installed libbsd (0.4.2-1)
[2013-04-13 18:04] [PACMAN] upgraded libwbclient (3.6.13-1 -> 4.0.5-1)
[2013-04-13 18:04] [PACMAN] upgraded cifs-utils (5.9-1 -> 6.0-1)
[2013-04-13 18:04] [PACMAN] upgraded cups-filters (1.0.33-1 -> 1.0.34-1)
[2013-04-13 18:04] [PACMAN] upgraded sqlite (3.7.16.1-1 -> 3.7.16.2-1)
[2013-04-13 18:04] [PACMAN] upgraded firefox (20.0-1 -> 20.0.1-2)
[2013-04-13 18:04] [PACMAN] upgraded firefox-i18n-de (20.0-1 -> 20.0.1-1)
[2013-04-13 18:04] [ALPM] warning: directory permissions differ on /usr/lib/mozilla/
filesystem: 705  package: 755
[2013-04-13 18:04] [PACMAN] upgraded flashplugin (11.2.202.275-1 -> 11.2.202.280-1)
[2013-04-13 18:04] [PACMAN] upgraded git (1.8.2-1 -> 1.8.2.1-1)
[2013-04-13 18:04] [PACMAN] upgraded harfbuzz (0.9.14-1 -> 0.9.15-1)
[2013-04-13 18:04] [PACMAN] upgraded isl (0.11.1-1 -> 0.11.1-2)
[2013-04-13 18:04] [PACMAN] upgraded lib32-glibc (2.17-4 -> 2.17-5)
[2013-04-13 18:04] [PACMAN] upgraded lib32-harfbuzz (0.9.14-1 -> 0.9.15-1)
[2013-04-13 18:04] [PACMAN] upgraded libpng (1.5.14-1 -> 1.5.15-1)
[2013-04-13 18:04] [PACMAN] upgraded lib32-libpng (1.5.14-1 -> 1.5.15-1)
[2013-04-13 18:04] [PACMAN] upgraded lib32-libxi (1.7-1 -> 1.7.1-1)
[2013-04-13 18:04] [PACMAN] upgraded lib32-systemd (198-1 -> 200-1)
[2013-04-13 18:04] [PACMAN] upgraded libdiscid (0.4.1-1 -> 0.5.0-1)
[2013-04-13 18:04] [PACMAN] upgraded libldap (2.4.34-1 -> 2.4.35-1)
[2013-04-13 18:04] [PACMAN] upgraded libmpdclient (2.7-1 -> 2.8-1)
[2013-04-13 18:04] [PACMAN] upgraded libva (1.1.0-2 -> 1.1.1-1)
[2013-04-13 18:04] [PACMAN] upgraded libwnck3 (3.4.4-1 -> 3.4.5-1)
[2013-04-13 18:04] [ALPM-SCRIPTLET] >>> Updating module dependencies. Please wait ...
[2013-04-13 18:04] [ALPM-SCRIPTLET] >>> Generating initial ramdisk, using mkinitcpio.  Please wait...
[2013-04-13 18:04] [ALPM-SCRIPTLET] ==> Building image from preset: 'default'
[2013-04-13 18:04] [ALPM-SCRIPTLET]   -> -k /boot/vmlinuz-linux -c /etc/mkinitcpio.conf -g /boot/initramfs-linux.img
[2013-04-13 18:04] [ALPM-SCRIPTLET] ==> Starting build: 3.8.6-1-ARCH
[2013-04-13 18:04] [ALPM-SCRIPTLET]   -> Running build hook: [base]
[2013-04-13 18:04] [ALPM-SCRIPTLET]   -> Running build hook: [udev]
[2013-04-13 18:04] [ALPM-SCRIPTLET]   -> Running build hook: [autodetect]
[2013-04-13 18:04] [ALPM-SCRIPTLET]   -> Running build hook: [modconf]
[2013-04-13 18:04] [ALPM-SCRIPTLET]   -> Running build hook: [block]
[2013-04-13 18:04] [ALPM-SCRIPTLET]   -> Running build hook: [resume]
[2013-04-13 18:04] [ALPM-SCRIPTLET]   -> Running build hook: [filesystems]
[2013-04-13 18:04] [ALPM-SCRIPTLET]   -> Running build hook: [keyboard]
[2013-04-13 18:04] [ALPM-SCRIPTLET]   -> Running build hook: [fsck]
[2013-04-13 18:04] [ALPM-SCRIPTLET] ==> Generating module dependencies
[2013-04-13 18:04] [ALPM-SCRIPTLET] ==> Creating gzip initcpio image: /boot/initramfs-linux.img
[2013-04-13 18:04] [ALPM-SCRIPTLET] ==> Image generation successful
[2013-04-13 18:04] [ALPM-SCRIPTLET] ==> Building image from preset: 'fallback'
[2013-04-13 18:04] [ALPM-SCRIPTLET]   -> -k /boot/vmlinuz-linux -c /etc/mkinitcpio.conf -g /boot/initramfs-linux-fallback.img -S autodetect
[2013-04-13 18:04] [ALPM-SCRIPTLET] ==> Starting build: 3.8.6-1-ARCH
[2013-04-13 18:04] [ALPM-SCRIPTLET]   -> Running build hook: [base]
[2013-04-13 18:04] [ALPM-SCRIPTLET]   -> Running build hook: [udev]
[2013-04-13 18:04] [ALPM-SCRIPTLET]   -> Running build hook: [modconf]
[2013-04-13 18:04] [ALPM-SCRIPTLET]   -> Running build hook: [block]
[2013-04-13 18:04] [ALPM-SCRIPTLET]   -> Running build hook: [resume]
[2013-04-13 18:04] [ALPM-SCRIPTLET]   -> Running build hook: [filesystems]
[2013-04-13 18:04] [ALPM-SCRIPTLET]   -> Running build hook: [keyboard]
[2013-04-13 18:04] [ALPM-SCRIPTLET]   -> Running build hook: [fsck]
[2013-04-13 18:04] [ALPM-SCRIPTLET] ==> Generating module dependencies
[2013-04-13 18:04] [ALPM-SCRIPTLET] ==> Creating gzip initcpio image: /boot/initramfs-linux-fallback.img
[2013-04-13 18:04] [ALPM-SCRIPTLET] ==> Image generation successful
[2013-04-13 18:04] [PACMAN] upgraded linux (3.8.5-1 -> 3.8.6-1)
[2013-04-13 18:05] [PACMAN] upgraded linux-headers (3.8.5-1 -> 3.8.6-1)
[2013-04-13 18:05] [PACMAN] upgraded lirc-utils (1:0.9.0-40 -> 1:0.9.0-41)
[2013-04-13 18:05] [PACMAN] upgraded lshw (B.02.16-3 -> B.02.16-4)
[2013-04-13 18:05] [ALPM] warning: /etc/mpd.conf installed as /etc/mpd.conf.pacnew
[2013-04-13 18:05] [PACMAN] upgraded mpd (0.17.3-3 -> 0.17.4-1)
[2013-04-13 18:05] [PACMAN] upgraded nspr (4.9.5-1 -> 4.9.6-1)
[2013-04-13 18:05] [PACMAN] upgraded orc (0.4.16-1 -> 0.4.17-1)
[2013-04-13 18:05] [PACMAN] upgraded perl-net-ssleay (1.52-1 -> 1.54-1)
[2013-04-13 18:05] [PACMAN] upgraded perl-io-socket-ssl (1.81-1 -> 1.84-1)
[2013-04-13 18:05] [PACMAN] upgraded python (3.3.0-3 -> 3.3.1-1)
[2013-04-13 18:05] [PACMAN] upgraded python2 (2.7.3-4 -> 2.7.4-1)
[2013-04-13 18:05] [PACMAN] upgraded python2-distribute (0.6.34-1 -> 0.6.36-1)
[2013-04-13 18:05] [PACMAN] upgraded python2-lxml (3.1.0-1 -> 3.1.1-1)
[2013-04-13 18:05] [PACMAN] upgraded qt3 (1:3.3.8b-3 -> 1:3.3.8b-4)
[2013-04-13 18:05] [PACMAN] upgraded sane (1.0.23-3 -> 1.0.23-4)
[2013-04-13 18:05] [PACMAN] installed tevent (0.9.18-1)
[2013-04-13 18:05] [PACMAN] installed ldb (1.1.15-1)
[2013-04-13 18:05] [PACMAN] upgraded smbclient (3.6.13-1 -> 4.0.5-1)
[2013-04-13 18:05] [PACMAN] upgraded sudo (1.8.6.p7-2 -> 1.8.6.p8-1)
[2013-04-13 18:05] [PACMAN] upgraded systemd-sysvcompat (200-1 -> 201-1)
[2013-04-13 18:05] [PACMAN] upgraded tp_smapi (0.41-16 -> 0.41-17)
[2013-04-13 18:05] [PACMAN] upgraded twisted (12.3.0-1 -> 13.0.0-1)
[2013-04-13 18:05] [PACMAN] upgraded vlc (2.0.5-5 -> 2.0.6-1)
[2013-04-13 18:05] [PACMAN] upgraded xf86-video-intel (2.21.5-1 -> 2.21.6-1)
[2013-04-13 18:05] [PACMAN] upgraded xulrunner (19.0.2-1 -> 20.0-1)

Ich weiß nicht, welche zusätzlichen logs hilfreich sein könnten. dmesg zeigt keine Unauffälligkeiten.

Danke für eure Hilfe und jeden Hinweis!

EDIT: Der Grund dürfte der Ethernet-Anschluss sein. Sobald der (ungenutzte) Anschluss per "ifconfig eth0 down" deaktiviert wird, ist die CPU-Auslastung normal.