SMP kernel problems...(SLOW performance)

[mikeycal]

I have been using Kubuntu 5.10 (Breezy) for the last few weeks on my HPzv5360us laptop and 2.6.12 SMP kernel seems to be broken. The (Hoary) 5.04 2.6.10 SMP kernel works perfectly on this laptop but as soon as I try to boot from the Breezy 2.6.12 SMP kernel the system slows to a crawl. Initially I thought is was a configuration issue since I did a dist-upgrade. So I download Kubuntu 5.10 RC and freshly reloaded my laptop -- same problem. The standard 2.6.12 i386 kernel seems to work fine but, obviously, it has no Hyper Threading support and only recognizes 1 CPU instead of 2 -- like it should. I looked around the ubuntu bugzilla and saw someone else had a simillar problem. There was also a comment that said HyperThreading for the SMP kernel must be turned on with a GRUB setting by adding "HT=on" to your boot command. I tried this but it didn't change anything. Anyway, anyone else having issues with SMP on their laptop? more importantly, anyone know if this issue is being fixed.

[Divan Santana]

Re: SMP kernel problems...(SLOW performance)

I have the exact same problem. I have a HP Compaq nx 9110 laptop which should have hyper-threading. The 386 kernel works way better than the 686smp kernel.

Don't know what to do, suppose will have to run my Kubuntu in 386 and configure vmware to run in 386 not 686smp ( Maybe they'll releaes a fix, has a bug report been genrated??

Any fixes for this?

[mikeycal]

Re: SMP kernel problems...(SLOW performance)

Just to keep you upto date on SMP kernels with (K)UBUNTU, I thought that maybe there was something wrong with UBUNTU's SMP kernel provided in the main repo; so I download, patched (with cK3), and built the latest 2.6.14 kernel. The bad news, is that the latest VANILLA kernel did the exact same thing -- ran slow when you enable SMP and HT. I am starting to think that this is not an Ubuntu issue, it's something broken in the the MAIN kernel since 2.6.11(the last version I got to work with SMP).

It appears that it only affects Uniprocessor- Pentium-4M with HT.

My specs:
P4m with HT 3.06 Ghz
768 M RAM
ATI 9000

[paralis]

Re: SMP kernel problems...(SLOW performance)

Kernel 2.6.12-9-686-smp works okay on dual Athlon MP. Must be HT related.

[whoiam55]

Re: SMP kernel problems...(SLOW performance)

Do you guys know any program for testing kernel performance ?

[paralis]

Re: SMP kernel problems...(SLOW performance)

Found this :

http://kernel-perf.sourceforge.net/about_tests.php

Hope it helps.