FS#25585 - [kde] Freezes after upgrade to 4.7

Attached to Project: Arch Linux
Opened by Nicola Mori (snack) - Monday, 15 August 2011, 14:40 GMT
Last edited by Andrea Scarpino (BaSh) - Wednesday, 19 October 2011, 09:06 GMT
Task Type Bug Report
Category Upstream Bugs
Status Closed
Assigned To Ronald van Haren (pressh)
Andrea Scarpino (BaSh)
Architecture All
Severity Medium
Priority Normal
Reported Version
Due in Version Undecided
Due Date Undecided
Percent Complete 100%
Votes 6
Private No

Details

Description:
After upgrade to KDE 4.7, my i686 system on my laptop freezes for about 10 seconds when doing some specific actions, like opening Lancelot launcer or trying to close the session. Meanwhile, HDD spins a lot. This only happens the first time I do the action, then it works quite normally but the desktop is anyway slow.
It only happens on my i686 laptop; on my x86_64 desktop and dual-boot laptop I have no issue.
Up to now, I tried to:

- disable nepomuk, strigi and all that using the nepomukcontroller plasmoid
- disable compositing
- delete .kde folder
- uninstall and reinstall all kde packages
- create a new user and start kde for that user
- use xf86-video-ati instead of catalyst
- reinstall all the packages (not only kde ones)
- launch kde using kdm and also with startx from command line
- downgrade to 4.6.5

Only downgrade improved the situation, so I fear it's something related to 4.7, but unfortunately I have no idea about the motivations. Other users experience the same issue also on x86_64:

https://bbs.archlinux.org/viewtopic.php?pid=976376#p976376

I'm sorry I can't provide more precise information, but I hope some other people can contribute.
This task depends upon

Closed by  Andrea Scarpino (BaSh)
Wednesday, 19 October 2011, 09:06 GMT
Reason for closing:  Upstream
Additional comments about closing:  Please follow the upstream bug report
Comment by Nicola Mori (snack) - Monday, 15 August 2011, 18:59 GMT
I think the problem is in the kdelibs package. I did a minimal 4.7 installation and tried to downgrade packages one by one to 4.6.5. When I downgraded kdelibs the desktop got screwed but still responsive. The HDD usage dropped and the logout dialog could pop up very quickly. I still don't know what's wrong but at least there is some hint where to look at...
Comment by Andrea Scarpino (BaSh) - Monday, 15 August 2011, 19:14 GMT
Mixing release or downgrade packages is useless.

Indeed:
- synchronize again your mirror with pacman -Syy
- disable [kde-unstable] if you use it, and do an upgrade of _ALL_ your packages using pacman -Suu. Try to reproduce the bug.
- remove your ~/.kde4 dir and your /var/tmp/kde-* dirs. Try to reproduce the bug.
You can also create a new user and see if you can reproduce the bug
Comment by Nicola Mori (snack) - Monday, 15 August 2011, 19:32 GMT
I did what you suggested, but there's still no improvement. I also tried with a new user, and the problem is still there.
Comment by Fabian Schwarz (F_abe) - Friday, 26 August 2011, 20:41 GMT
Same problem here!

After the update to KDE SC 4.7 it's noticeable slower, especially on startup.
Comment by Nicola Mori (snack) - Sunday, 11 September 2011, 16:01 GMT
After upgrade of kde to 4.7.1 the problem still persist.
I realized that on the system where I experience the slowdown I have an ext3 root partition, while in the other two systems which does not have the slowdown problem the root partition is ext4. Could this be part of the problem?
I also saw (using iotop) that during the anomalous disk activity and the consequent slowdown kjournald is using about 100% of disk.
Comment by Nicola Mori (snack) - Monday, 12 September 2011, 10:51 GMT
I've been able to mount root partition as ext4 using the rootfstype=ext4 kernel command line option, but it didn't solve the problem. Maybe mounting ext3 as ext4 is not equivalent to having a native ext4 root partition...
Anyway, F_abe reported the same problem; which fs type you have on your root partition?
Comment by Fabian Schwarz (F_abe) - Monday, 12 September 2011, 12:09 GMT
I'm also using an ext3 partition.
But could it generally be possible that the problem is related with the fs type? I mean accessing the filesystem etc. is still part of the kernel which provides these IO actions to the user space programs, isn't it?
I'm also going to look at the iotop output at the next start of KDE...

But it's really strange that there are only few people complaining about that problem!?
Comment by Nicola Mori (snack) - Monday, 12 September 2011, 13:24 GMT
My hypothesis is that 4.7 introduced something (a process, a daemon, whatever) which tries to do operations on the disk in a way that is fast on ext4 but very slow on ext3. So it is not an ext3 problem, but rather an application which is very inefficient on ext3 filesystems.
But I'm not an expert in fs types, so I have no idea if this could be a valid hypothesis...
Comment by Nicola Mori (snack) - Saturday, 24 September 2011, 17:34 GMT
I did two fresh i686 installations on a spare partition on my desktop. For the first one, I used an ext3 root partition and I noticed the freezes and the slowdown. The second one was done using ext4 for root partition and it had no problems at all.
So I really think that the issue is using ext3 for root partition. I didn't try with x86_64, but I'm going to do it soon.
Comment by Nicola Mori (snack) - Saturday, 24 September 2011, 17:51 GMT
I opened an upstream bug report:

https://bugs.kde.org/show_bug.cgi?id=282704

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