[Bug 475706] Re: ondemand cpufreq governor broken on core 2 duo cpu
Dawid Ciężarkiewicz
dpc at ucore.info
Fri Apr 23 21:38:17 UTC 2010
apport information
** Tags added: apport-collected
** Description changed:
I've installed fresh 9.10 and I'm with the defaults. This is how I've
noticed the following behaviour and I want to share it.
As I have two cores - I've setup two cpufreq scaling monitors applets.
By default my idle system is working on 1.00Ghz on both CPUs (cores to
be precise).
In one console I do:
while :; do echo -n "" ; done
htop shows that CPU1 goes 100% and CPU1 scaling monitor shows that CPU1
goes 1.8Ghz (max) right away.
So I open another console and do:
while :; do echo -n "" ; done
but CPU0 goes 100% but CPU0 scalling monitor show that CPU0 is only at
1.33Ghz and this is not changing through time.
Now comes the funny part.
I press the Ctrl+c in one of the consoles and now both CPUs go 1.00Ghz
while CPU0 is working 100% and the other almost idle !
I've recreated this behaviour few times (100% reproduction rate).
This behaviour is not visible when both CPUs use i.e. conservative
cpufreq. I have no idea behind the logic ondeman cpufreq gov. is being
driven, but for me ubuntu always had a problems with it.
The other thing is this - when watching the following in HD:
http://www.youtube.com/watch?v=zlfKdbWwruY
I'm unable to get any CPU to work on 1.8Ghz and the movie is skipping
frequently due to underperformed decoding / display.
So I've played around and changed cpu?/cpufreq/ondemand/up_threshold
from default 95 to 30 . Now everything is perfectly fine. The original
funny behaviour is gone.
I think that 95 is way to high for default. I want my CPU to work on
high speed if required and slow down if there's nothing to do. (as per
http://www.lesswatts.org/projects/applications-power-management/race-to-
idle.php )
Maybe 5% margin is not enough to catch quickly that the there's a CPU
shortage here and there. I'm not sure, but someone with more time and
knowledge should take a look at this.
ProblemType: Bug
Architecture: amd64
AudioDevicesInUse:
USER PID ACCESS COMMAND
/dev/snd/controlC0: dpc 1723 F.... pulseaudio
/dev/snd/pcmC0D0p: dpc 1723 F...m pulseaudio
CRDA: Error: [Errno 2] No such file or directory
Card0.Amixer.info:
Card hw:0 'Intel'/'HDA Intel at 0xf1200000 irq 22'
Mixer name : 'Realtek ALC883'
Components : 'HDA:10ec0883,15580721,00100002 HDA:10573055,10573055,00100700'
Controls : 28
Simple ctrls : 17
Date: Thu Nov 5 19:21:02 2009
DistroRelease: Ubuntu 9.10
HibernationDevice: RESUME=UUID=32932d31-e3e8-4410-825a-26f418ee7240
InstallationMedia: Ubuntu 9.10 "Karmic Koala" - Release amd64 (20091027)
MachineType: ARISTO Slim 1250
Package: linux-image-2.6.31-14-generic 2.6.31-14.48
ProcCmdLine: BOOT_IMAGE=/boot/vmlinuz-2.6.31-14-generic root=UUID=95827051-2f3b-467f-9f8a-d99370280630 ro quiet splash
ProcEnviron:
LANG=en_US.UTF-8
SHELL=/bin/bash
ProcVersionSignature: Ubuntu 2.6.31-14.48-generic
RelatedPackageVersions:
linux-backports-modules-2.6.31-14-generic N/A
linux-firmware 1.24
RfKill:
0: phy0: Wireless LAN
Soft blocked: no
Hard blocked: no
SourcePackage: linux
Uname: Linux 2.6.31-14-generic x86_64
dmi.bios.date: 01/10/2008
dmi.bios.vendor: Phoenix Technologies LTD
dmi.bios.version: SROSA001.86C.0038.D.080110
dmi.board.name: Slim 1250
dmi.board.vendor: ARISTO
dmi.board.version: Not Applicable
dmi.chassis.asset.tag: No Asset Tag
dmi.chassis.type: 1
dmi.chassis.vendor: ARISTO
dmi.chassis.version: N/A
dmi.modalias: dmi:bvnPhoenixTechnologiesLTD:bvrSROSA001.86C.0038.D.080110:bd01/10/2008:svnARISTO:pnSlim1250:pvrNotApplicable:rvnARISTO:rnSlim1250:rvrNotApplicable:cvnARISTO:ct1:cvrN/A:
dmi.product.name: Slim 1250
dmi.product.version: Not Applicable
dmi.sys.vendor: ARISTO
+ ---
+ AlsaVersion: Advanced Linux Sound Architecture Driver Version 1.0.21.
+ Architecture: amd64
+ AudioDevicesInUse:
+ USER PID ACCESS COMMAND
+ /dev/snd/controlC0: dpc 1698 F.... pulseaudio
+ /dev/snd/pcmC0D0p: dpc 1698 F...m pulseaudio
+ CRDA: Error: [Errno 2] No such file or directory
+ Card0.Amixer.info:
+ Card hw:0 'Intel'/'HDA Intel at 0xf1200000 irq 22'
+ Mixer name : 'Realtek ALC883'
+ Components : 'HDA:10ec0883,15580721,00100002 HDA:10573055,10573055,00100700'
+ Controls : 28
+ Simple ctrls : 17
+ DistroRelease: Ubuntu 10.04
+ EcryptfsInUse: Yes
+ HibernationDevice: RESUME=UUID=32932d31-e3e8-4410-825a-26f418ee7240
+ InstallationMedia: Ubuntu 10.04 "Lucid Lynx" - Beta amd64 (20100318)
+ MachineType: ARISTO Slim 1250
+ Package: linux (not installed)
+ ProcCmdLine: BOOT_IMAGE=/boot/vmlinuz-2.6.32-21-generic root=UUID=d5a869b3-8494-4faa-8d0d-aa0c3b797a9b ro quiet splash
+ ProcEnviron:
+ PATH=(custom, user)
+ LANG=en_GB.utf8
+ SHELL=/bin/bash
+ ProcVersionSignature: Ubuntu 2.6.32-21.32-generic 2.6.32.11+drm33.2
+ Regression: No
+ RelatedPackageVersions: linux-firmware 1.34
+ Reproducible: Yes
+ RfKill:
+ 0: phy0: Wireless LAN
+ Soft blocked: no
+ Hard blocked: no
+ Tags: lucid needs-upstream-testing
+ Uname: Linux 2.6.32-21-generic x86_64
+ UserGroups: adm admin cdrom dialout lp lpadmin plugdev sambashare
+ WifiSyslog:
+
+ dmi.bios.date: 01/10/2008
+ dmi.bios.vendor: Phoenix Technologies LTD
+ dmi.bios.version: SROSA001.86C.0038.D.080110
+ dmi.board.name: Slim 1250
+ dmi.board.vendor: ARISTO
+ dmi.board.version: Not Applicable
+ dmi.chassis.asset.tag: No Asset Tag
+ dmi.chassis.type: 1
+ dmi.chassis.vendor: ARISTO
+ dmi.chassis.version: N/A
+ dmi.modalias: dmi:bvnPhoenixTechnologiesLTD:bvrSROSA001.86C.0038.D.080110:bd01/10/2008:svnARISTO:pnSlim1250:pvrNotApplicable:rvnARISTO:rnSlim1250:rvrNotApplicable:cvnARISTO:ct1:cvrN/A:
+ dmi.product.name: Slim 1250
+ dmi.product.version: Not Applicable
+ dmi.sys.vendor: ARISTO
** Attachment added: "AlsaDevices.txt"
http://launchpadlibrarian.net/45128191/AlsaDevices.txt
--
ondemand cpufreq governor broken on core 2 duo cpu
https://bugs.launchpad.net/bugs/475706
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