Tuesday, March 11, 2008

Stop freezes gutsy linux

Since i updated to gutsy i was experiencing freezes whenever the power status changed, for example when i switched from AC power to battery and vise versa.
I was not even able to login after installing gutsy and it would freeze at GDM level, i remember i had to prevent powernowd from loading at boot. This made me possible to login.
I would also get freezes whenever there was intense CPU use for a period of say 10 secs or more. This would happen for example when a web page in being loaded which has got some Java applications.
I was fiddling a bit with the system last week, i wondered any one of the updates since gutsy release has managed to resolve this issue. So i opened system->Administration->services, enabled powernowd. That was it, system had an instant freeze and i had to do cold reboot.

But now i started facing the same old problem of reaching till GDM and the system freezes.
I tried to boot into recovery mode and did
/etc/init.d/powernowd stop
that would allow me to select GDM and login normally. But once i did reboot i would experience the same freeze at Gdm, which is understandable since stoping powernowd worked only for that session.
so i was left with the only option of getting rid of powernowd.
I was back in recovery mode and did a
apt-get remove powernowd
That did the trick, i can login without any problem and to my surprise i am no longer experiencing the freezes i use to get with power status change and with intense CPU use.
In effect, i lost CPU frequency scaling and gained in the sense that it stopped the freezes on the laptop.
I am not sure of the implications of running the CPU at full scale all the time but i am more than happy of not seeing any more freezes and having to do a hard reboot.