Computer very slow since update to Ubuntu 17.04

[Michael Bonfils]

After upgrading my Dell Latitude E6400, computer was running very slowly.

After few search, with powertop, I found that three modules was consuming lot of CPU:
- snd_hda_codec_idt
- snd_hda_codec_generic
- snd_hda_intel
(like https://askubuntu.com/questions/91359/100-0-usage-by-audio-codec-hwc0d0-realtek)

After adding them in /etc/modprobe.d/blacklist-snd.conf, my computer works again like a charm, with cost of missing sound.

Ubuntu 4.10.0-20.22-generic 4.10.8
---
ApportVersion: 2.20.4-0ubuntu4
Architecture: amd64
AudioDevicesInUse: Error: command ['fuser', '-v', '/dev/snd/seq', '/dev/snd/timer'] failed with exit code 1:
CurrentDesktop: XFCE
DistroRelease: Ubuntu 17.04
HibernationDevice: RESUME=UUID=0ae2ebf0-deb2-41a5-9097-993b2b8ae91c
InstallationDate: Installed on 2016-03-03 (435 days ago)
InstallationMedia: Xubuntu Core 15.04 - amd64 - 20150425
MachineType: Dell Inc. Latitude E6400
Package: linux (not installed)
PccardctlIdent:
 Socket 0:
   no product info available
PccardctlStatus:
 Socket 0:
   no card
ProcFB: 0 inteldrmfb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.10.0-20-generic root=UUID=bbcbd90b-01c5-4ac8-8b33-bdfef07019fc ro quiet splash vt.handoff=7
ProcVersionSignature: Ubuntu 4.10.0-20.22-generic 4.10.8
RelatedPackageVersions:
 linux-restricted-modules-4.10.0-20-generic N/A
 linux-backports-modules-4.10.0-20-generic N/A
 linux-firmware 1.164.1
Tags: zesty
Uname: Linux 4.10.0-20-generic x86_64
UpgradeStatus: Upgraded to zesty on 2017-05-02 (10 days ago)
UserGroups: adm cdrom dip docker lpadmin plugdev sambashare sudo wireshark
_MarkForUpload: True
dmi.bios.date: 12/21/2009
dmi.bios.vendor: Dell Inc.
dmi.bios.version: A20
dmi.board.name: 0W620R
dmi.board.vendor: Dell Inc.
dmi.chassis.type: 8
dmi.chassis.vendor: Dell Inc.
dmi.modalias: dmi:bvnDellInc.:bvrA20:bd12/21/2009:svnDellInc.:pnLatitudeE6400:pvr:rvnDellInc.:rn0W620R:rvr:cvnDellInc.:ct8:cvr:
dmi.product.name: Latitude E6400
dmi.sys.vendor: Dell Inc.

[Brad Figg (brad-figg)]

This bug is missing log files that will aid in diagnosing the problem. From a terminal window please run:

apport-collect 1690357

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.

[Michael Bonfils (murlock)]

apport information

[Michael Bonfils (murlock)]

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[Michael Bonfils (murlock)]

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[Michael Bonfils (murlock)]

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[Michael Bonfils (murlock)]

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[Michael Bonfils (murlock)]

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[Michael Bonfils (murlock)]

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[Michael Bonfils (murlock)]

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[Michael Bonfils (murlock)]

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[Michael Bonfils (murlock)]

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[Michael Bonfils (murlock)]

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[Michael Bonfils (murlock)]

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[Michael Bonfils (murlock)]

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[Michael Bonfils (murlock)]

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[Michael Bonfils (murlock)]

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[Michael Bonfils (murlock)]

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[Michael Bonfils (murlock)]

Please note that apport-collect was made with disabled faulty modules

[Joseph Salisbury (jsalisbury)]

Would it be possible for you to test the latest upstream kernel? Refer to https://wiki.ubuntu.com/KernelMainlineBuilds . Please test the latest v4.12 kernel[0].

If this bug is fixed in the mainline kernel, please add the following tag 'kernel-fixed-upstream'.

If the mainline kernel does not fix this bug, please add the tag: 'kernel-bug-exists-upstream'.

Once testing of the upstream kernel is complete, please mark this bug as "Confirmed".

Thanks in advance.

[0] http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.12-rc1/

[Michael Bonfils (murlock)]

Verified with Linux E6400 4.12.0-041200rc1-generic #201705131731 SMP Sat May 13 21:32:36 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux

powertop show Audio codec hwC0D2: Intel, hwC0D1: Conexant and hwC0D0: IDT at 100%

[Kai-Heng Feng (kaihengfeng)]

So the issue didn't happen in 16.10 kernel (4.8)?

[Michael Bonfils (murlock)]

Sorry for the delay.

I want to amend my previous comments:

with kernel 4.12, powertop still report Audio codec using 100% but my laptop is not slow !

This happens only with kernel 4.10.

Regarding Ubuntu 16.10, I've upgraded my laptop from 16.04 to 16.10 and then to 17.04 in a row, but I don't remember any issue with 16.10.

I think we could close this ticket or if you have some test that I could launch, I am at your disposal.

Regards,
Michael

[Kai-Heng Feng (kaihengfeng)]

Probably still need to find the commit fixes the slowness.

As soon as you enable runtime power management for audio codec, it should drop to 0%.