There is a spurious OOM issue with PAE kernel: it will suffer an OOM
crash just by running a few processes.
Please see also
http://bugs.debian.org/695182
and discussion on <email address hidden> e.g.
http://marc.info/?l=linux-mm&m=135801969519193&w=2
I wonder whether
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1098342
is related.
The issue is a regression with PAE, reproduced and verified on my
home PC with 3GB RAM.
My PC was running kernel linux-image-3.2.0-35-generic so it showed:
psz@DellE520:~$ uname -a
Linux DellE520 3.2.0-35-generic #55-Ubuntu SMP Wed Dec 5 17:45:18 UTC 2012 i686 i686 i386 GNU/Linux
psz@DellE520:~$ free -l
total used free shared buffers cached
Mem: 3087972 692256 2395716 0 18276 427116
Low: 861464 71372 790092
High: 2226508 620884 1605624
-/+ buffers/cache: 246864 2841108
Swap: 20000920 258364 19742556
Then it handled the "sleep test"
bash -c 'n=0; while [ $n -lt 33000 ]; do sleep 600 & ((n=n+1)); ((m=n%500)); if [ $m -lt 1 ]; then echo -n "$n - "; date; free -l; sleep 1; fi; done'
just fine, stopped only by "max user processes" (default setting of
"ulimit -u 23964"), or raising that limit stopped when the machine ran
out of PID space; there was no OOM.
Installing and running the PAE kernel so it showed:
psz@DellE520:~$ uname -a
Linux DellE520 3.2.0-35-generic-pae #55-Ubuntu SMP Wed Dec 5 18:04:39 UTC 2012 i686 i686 i386 GNU/Linux
psz@DellE520:~$ free -l
total used free shared buffers cached
Mem: 3087620 681188 2406432 0 167332 352296
Low: 865208 214080 651128
High: 2222412 467108 1755304
-/+ buffers/cache: 161560 2926060
Swap: 20000920 0 20000920
and re-trying the "sleep test", it ran into OOM after 18000 or so sleeps
and crashed/froze so I had to press the POWER button to recover.
Cheers, Paul
Paul Szabo <email address hidden> http://www.maths.usyd.edu.au/u/psz/
School of Mathematics and Statistics University of Sydney Australia
---
AlsaVersion: Advanced Linux Sound Architecture Driver Version 1.0.24.
AplayDevices:
**** List of PLAYBACK Hardware Devices ****
card 0: Intel [HDA Intel], device 0: STAC92xx Analog [STAC92xx Analog]
Subdevices: 1/1
Subdevice #0: subdevice #0
ApportVersion: 2.0.1-0ubuntu15.1
Architecture: i386
AudioDevicesInUse:
USER PID ACCESS COMMAND
/dev/snd/controlC0: psz 2190 F.... pulseaudio
CRDA: Error: command ['iw', 'reg', 'get'] failed with exit code 1: nl80211 not found.
Card0.Amixer.info:
Card hw:0 'Intel'/'HDA Intel at 0xdfddc000 irq 45'
Mixer name : 'SigmaTel STAC9227'
Components : 'HDA:83847618,102801dd,00100201'
Controls : 38
Simple ctrls : 21
CurrentDmesg: [ 28.160013] eth0: no IPv6 routers present
DistroRelease: Ubuntu 12.04
HibernationDevice: RESUME=UUID=9d2bf7ac-9b0a-4082-ac45-f4d3c8e32c23
IwConfig:
lo no wireless extensions.
eth0 no wireless extensions.
MachineType: Dell Inc. Dell DM061
MarkForUpload: True
Package: linux (not installed)
ProcEnviron:
TERM=xterm
PATH=(custom, no user)
LANG=C
SHELL=/bin/bash
ProcFB: 0 inteldrmfb
ProcKernelCmdLine: root=/dev/mapper/isw_cheedcedhh_DadMirroredTB4 ro quiet splash
ProcVersionSignature: Ubuntu 3.2.0-35.55-generic-pae 3.2.34
RelatedPackageVersions:
linux-restricted-modules-3.2.0-35-generic-pae N/A
linux-backports-modules-3.2.0-35-generic-pae N/A
linux-firmware 1.79.1
RfKill:
Tags: precise
Uname: Linux 3.2.0-35-generic-pae i686
UpgradeStatus: Upgraded to precise on 2012-04-27 (260 days ago)
UserGroups: adm admin cdrom dialout lpadmin plugdev sambashare
WifiSyslog: Jan 13 06:42:46 DellE520 NetworkManager[1384]: <info> Unmanaged Device found; state CONNECTED forced. (see http://bugs.launchpad.net/bugs/191889)
WpaSupplicantLog:
dmi.bios.date: 03/23/2007
dmi.bios.vendor: Dell Inc.
dmi.bios.version: 2.2.1
dmi.board.name: 0WG864
dmi.board.vendor: Dell Inc.
dmi.chassis.type: 6
dmi.chassis.vendor: Dell Inc.
dmi.modalias: dmi:bvnDellInc.:bvr2.2.1:bd03/23/2007:svnDellInc.:pnDellDM061:pvr:rvnDellInc.:rn0WG864:rvr:cvnDellInc.:ct6:cvr:
dmi.product.name: Dell DM061
dmi.sys.vendor: Dell Inc.
This bug is missing log files that will aid in diagnosing the problem. From a terminal window please run:
apport-collect 1098961
and then change the status of the bug to 'Confirmed'.
If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'.
This change has been made by an automated script, maintained by the Ubuntu Kernel Team.