kslowd causing periodic system lag

[James78]

My server sometimes has slow SSH logins, and slow sessions (e.g. stuttering text entry). I don't know if it's related to this, but it's very possible, especially when I checked top.

[aezren]

I have the same kslowd000 issue as well. I have several processes keep running kslowd000, kslowd001, kslow002, etc... I have same symptoms as everyone else. Sluggish mouse, stuttering mp3 playback, etc. I am thinking about the kernel downgrade, just have not had time to try it yet. I am running 64 bit Maverick kernel 2.6.35-22-generic. I have a Lenovo T400 laptop. I'll have to do something soon. This is starting to really get annoying

[aezren]

found this bug report:
https://bugs.launchpad.net/ubuntu/+s...ux/+bug/662946

I installed the kernel 2.6.36 as recommended and so far so good. I'll try it out for a while and let you know how it goes.

[James78]

Edit:: Using 2.6.36 kernel right now. There's still some slowdown, but it's greatly decreased compared to the last kernel. It's much better, so I'm still happy.

Current links to AMD64 packages as of this posting date:

linux-headers-2.6.36-1_2.6.36-1.7_all.deb
http://archive.ubuntu.com/ubuntu/poo...36-1.7_all.deb

linux-headers-2.6.36-1-generic_2.6.36-1.7_amd64.deb
http://archive.ubuntu.com/ubuntu/poo...-1.7_amd64.deb

linux-image-2.6.36-1-generic_2.6.36-1.7_amd64.deb
http://archive.ubuntu.com/ubuntu/poo...-1.7_amd64.deb

For the ones that say amd64 on the end, replace with i386 for x86 versions.

[aezren]

So I have been running the 2.6.36-1-generic for a few days now. Seems better, not perfect, but much better. Problem is since upgrading the kernel my laptop battery will no longer give an estimate of time remaining. It just says (estimating...)

I noticed when i installed it is said it was geared toward desktop systems. I looked at all of the kernels available and this seemed like the best 64 bit choice for my Lenovo T400. Any ideas how to fix the time estimate?

[James78]

Other than downgrading, no idea. The newer kernels graphics drivers cause screen tearing for me, either that, or it's Xorg (don't Xorg drivers compile as modules into the kernel? That'd mean it's still Xorg in that case), where 10.04 was fine. Frustrating...

Edit:: After some testing, it appears it might be related to KDE graphics effects.

[ageyfman]

I had this issue with 10.10, on a Core2Duo machine, headless, running Maverick Server, and I think I just fixed it by upgrading to a new kernel. The new kernel I went to was 2.6.37-11.

I was seeing this issue after about 5 mins of uptime. Every time. My load avg would go up and up, until it reached about 20, at which point I could no longer SSH into the machine, or really do anything at all.

I tried both to upgrade from 2.6.35-22 to 2.6.35-24 and to 2.6.37-11. The 35-24 upgrade did not work. I would continue getting the kslowd000 and kslowd001 (001 especially) taking up 100% of CPU (Core 2 Duo DESKTOP, not laptop, headless).

So, I installed the Lucid Kernel PPA:

sudo add-apt-repository ppa:kernel-ppa/ppa

then installed the new kernel headers and image

sudo apt-get install linux-headers-2.6.37-11 linux-image-2.6.37-11

then reboot

sudo reboot

after 20 mins of uptime, I am not seeing the kslowd001 process taking up any noticeable CPU.

[aezren]

I was able to solve this a few weeks ago as well. I upgraded to kernel 2.6.36.2 from http://kernel.ubuntu.com/~kernel-ppa....6.36.2-natty/

I tried a version of 2.6.37.x RC and had issues shutting down properly so I install the latest non RC version. At that time it was 2.6.36.2

After upgrading I would still have minor mouse lag every once in a while. To fix this I disabled polling of the drm_kms_helper and have not had an issues since.

sudo -i
echo "options drm_kms_helper poll=N">/etc/modprobe.d/local.conf
reboot

After upgrading to the newer generic kernel my laptop battery indicator would no longer work. It would not tell me how much time or percentage was left on the battery. To fix this I install IBAM and vubat. This works much better than the standard gnome battery indicator ever did. It is a very reliable battery indicator. The gnome indicator time was always all over the place anyway.

[noxan]

I have the problems (a process named kslowd002 appears with up to 5% cpu usage while my mouse pointer and the music playback stop for less than a second), but only if i plug in my external monitor via HDMI - if i unplug it, everything works fine again (no matter if the monitor is enabled in ubuntu or not).

I am running ubuntu10.04LTS (2.6.32-27) at the moment with enabled nvidia driver and had the same problems with a ubuntu10.10 installation and clean live-sytem.

edit:
updated to the version aezren linked and "disabled polling of the drm_kms_helper": works fine as long as i don't plug in my monitor ... :/
if i plug in my monitor again there isn't a kslowd002 process anymore, but the short lag of my mouse pointer still exists...?

[mal205]

I've had this problem on a Lenovo T400. I tried turning the polling off, with no success. Finally I loaded Kernel 2.6.38-020638rc4-generic. An hour in and it's all looking good.