It just (started) to happen again, I started 2 memory-demanding programs (each using 2GiB memory approx.), I do however have 8GiB memory installed. The system froze for 2 Minutes (or so), no mouse cursor, sound stopped, sporadic hard disk activity. Afterwards (from top): 13546 tbfg 20 0 906m 10m 3184 R 79,5 0,1 1:24.37 gnome-settings- 15316 tbfg 20 0 405m 129m 844 R 27,9 1,6 0:23.68 dconf-service gnome-settings-daemon and dconf-service started to use (combined) 100% CPU usage and both started to eat up memory. dmesg only shows: [57726.545257] cherry 0003:046A:0023.0002: >control queue full [57726.549750] cherry 0003:046A:0023.0002: >control queue full [57726.557497] cherry 0003:046A:0023.0002: >control queue full /var/log/syslog may have something: Oct 22 14:03:12 tbfg-desktop rtkit-daemon[1789]: The canary thread is apparently starving. Taking action. Oct 22 14:03:12 tbfg-desktop rtkit-daemon[1789]: Demoting known real-time threads. Oct 22 14:03:12 tbfg-desktop rtkit-daemon[1789]: Successfully demoted thread 2171 of process 2169 (n/a). Oct 22 14:03:12 tbfg-desktop rtkit-daemon[1789]: Successfully demoted thread 2170 of process 2169 (n/a). Oct 22 14:03:12 tbfg-desktop rtkit-daemon[1789]: Successfully demoted thread 2169 of process 2169 (n/a). Oct 22 14:03:12 tbfg-desktop rtkit-daemon[1789]: Demoted 3 threads. Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: snd_pcm_avail() returned a value that is exceptionally large: 406940 bytes (2306 ms). Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: Most likely this is a bug in the ALSA driver 'snd_hda_intel'. Please report this issue to the ALSA developers. Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: snd_pcm_dump(): Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: Soft volume PCM Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: Control: PCM Playback Volume Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: min_dB: -51 Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: max_dB: 0 Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: resolution: 256 Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: Its setup is: Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: stream : PLAYBACK Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: access : MMAP_INTERLEAVED Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: format : S16_LE Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: subformat : STD Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: channels : 2 Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: rate : 44100 Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: exact rate : 44100 (44100/1) Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: msbits : 16 Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: buffer_size : 16384 Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: period_size : 8192 Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: period_time : 185759 Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: tstamp_mode : ENABLE Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: period_step : 1 Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: avail_min : 15944 Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: period_event : 0 Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: start_threshold : -1 Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: stop_threshold : 4611686018427387904 Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: silence_threshold: 0 Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: silence_size : 0 Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: boundary : 4611686018427387904 Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: Slave: Hardware PCM card 0 'HDA Intel PCH' device 0 subdevice 0 Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: Its setup is: Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: stream : PLAYBACK Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: access : MMAP_INTERLEAVED Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: format : S16_LE Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: subformat : STD Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: channels : 2 Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: rate : 44100 Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: exact rate : 44100 (44100/1) Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: msbits : 16 Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: buffer_size : 16384 Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: period_size : 8192 Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: period_time : 185759 Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: tstamp_mode : ENABLE Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: period_step : 1 Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: avail_min : 15944 Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: period_event : 0 Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: start_threshold : -1 Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: stop_threshold : 4611686018427387904 Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: silence_threshold: 0 Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: silence_size : 0 Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: boundary : 4611686018427387904 Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: appl_ptr : 703774793 Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: hw_ptr : 703860144 Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: snd_pcm_delay() returned a value that is exceptionally large: -50162108 bytes (-284365 ms). Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: Most likely this is a bug in the ALSA driver 'snd_hda_intel'. Please report this issue to the ALSA developers. Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: snd_pcm_dump(): Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: Soft volume PCM Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: Control: PCM Playback Volume Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: min_dB: -51 Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: max_dB: 0 Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: resolution: 256 Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: Its setup is: Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: stream : PLAYBACK Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: access : MMAP_INTERLEAVED Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: format : S16_LE Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: subformat : STD Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: channels : 2 Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: rate : 44100 Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: exact rate : 44100 (44100/1) Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: msbits : 16 Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: buffer_size : 16384 Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: period_size : 8192 Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: period_time : 185759 Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: tstamp_mode : ENABLE Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: period_step : 1 Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: avail_min : 15944 Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: period_event : 0 Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: start_threshold : -1 Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: stop_threshold : 4611686018427387904 Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: silence_threshold: 0 Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: silence_size : 0 Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: boundary : 4611686018427387904 Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: Slave: Hardware PCM card 0 'HDA Intel PCH' device 0 subdevice 0 Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: Its setup is: Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: stream : PLAYBACK Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: access : MMAP_INTERLEAVED Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: format : S16_LE Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: subformat : STD Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: channels : 2 Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: rate : 44100 Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: exact rate : 44100 (44100/1) Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: msbits : 16 Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: buffer_size : 16384 Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: period_size : 8192 Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: period_time : 185759 Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: tstamp_mode : ENABLE Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: period_step : 1 Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: avail_min : 15944 Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: period_event : 0 Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: start_threshold : -1 Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: stop_threshold : 4611686018427387904 Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: silence_threshold: 0 Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: silence_size : 0 Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: boundary : 4611686018427387904 Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: appl_ptr : 703806545 Oct 22 14:03:12 tbfg-desktop pulseaudio[2169]: [alsa-sink] alsa-util.c: hw_ptr : 716347072 Oct 22 14:03:45 tbfg-desktop kernel: [57618.721067] cherry 0003:046A:0023.0002: >control queue full Oct 22 14:03:45 tbfg-desktop kernel: [57618.727033] cherry 0003:046A:0023.0002: >control queue full ^^ many many lines of cherry control queue full .... and eventually: Oct 22 14:07:40 tbfg-desktop kernel: [57854.051541] MYPROGRAM[31087]: segfault at 2ad9b9c7a018 ip 00000000004329a0 sp 00007fff5bd21f60 error 4 in MYPROGRAM[400000+50000] the system is then usable again