After upgrade to 12.04, X briefly freezes during I/O activity

[Akom]

This machine was fast as lightning on 11.10, on the same hardware (Dell Precision M4400, 8GB RAM)

After upgrade, X now freezes completely (nothing is updated on the screen, including load monitors) for periods of 1-10 seconds.

This typically occurs during I/O, here are the typical causes:

- Opening a new blank tab in Chrome (version 18.0.1025.168)
- Reloading an existing page in Chrome
- Opening or saving a file in Eclipse (3.7.2 from apt-get, type of file doesn't matter)

This does not occur when opening a file in a simple text editor, or launching most small applications, nor does it seem to affect Firefox. It is possible that this isn't related to I/O but instead to x input, process allocation, etc. I would even say it's a Chrome issue but Eclipse and Chrome both started doing this with 12.04, thus I'm guessing it's systemic.

Tried running Chrome from a clean config (no plugins) - same effect.

The system is not SWAPPING at all, there is plenty of ram, and top reports no wait. dmesg shows no obvious errors. CPU meters appear to spike during the pause (1 of the 2 cores), but I can't be 100% sure because the screen doesn't update until after.

When I run Windows 7 in VirtualBox, the guest itself runs with no delays.

I've installed preload, which made little difference.

Attached is the output of hdparm -I, hdparm -tT, smartctl -a, lspci -vvn, vmstat -2

The vmstat output covers several of these major pauses, especially towards the end (the last 12-15 rows were all printed only after it unfroze).

This bug is similar to https://bugs.launchpad.net/ubuntu/+source/linux-source-2.6.22/+bug/131094 and https://bugs.launchpad.net/ubuntu/+source/linux-source-2.6.22/+bug/131094
but I don't think they are the same.

Let me know if I can supply anything else.

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: xorg 1:7.6+12ubuntu1
ProcVersionSignature: Ubuntu 3.2.0-24.37-generic 3.2.14
Uname: Linux 3.2.0-24-generic x86_64
ApportVersion: 2.0.1-0ubuntu7
Architecture: amd64
Date: Thu May 10 10:15:43 2012
InstallationMedia: Xubuntu 11.10 "Oneiric Ocelot" - Release amd64 (20111012)
ProcEnviron:
 LANGUAGE=en_US:en
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: xorg
UpgradeStatus: Upgraded to precise on 2012-04-30 (9 days ago)

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[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 v3.5kernel[0] (Not a kernel in the daily directory) and install both the linux-image and linux-image-extra .deb packages.

Once you've tested the upstream kernel, please remove the 'needs-upstream-testing' tag(Only that one tag, please leave the other tags). This can be done by clicking on the yellow pencil icon next to the tag located at the bottom of the bug description and deleting the 'needs-upstream-testing' text.

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'.

If you are unable to test the mainline kernel, for example it will not boot, please add the tag: 'kernel-unable-to-test-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/v3.5-rc4-quantal/

[Launchpad Janitor (janitor)]

[Expired for linux (Ubuntu) because there has been no activity for 60 days.]