Friday, 5 June 2009

Kernel Mode Setting

There has been much hype over Kernel Mode Setting (KMS) support in the Linux Kernel. KMS is claimed to improve the boot experience, speed up boot and suspend/resume, make suspend/resume more reliable, improve crash reporting, and make you breakfast in bed. I was therefore somewhat sceptical that it would be so world changing.

During the recent Ubuntu Developer Summit I had the opportunity to be involved in planning for the kernel side of KMS and had the chance to see some machines setup with KMS enabled. I can only say I was impressed with the improvements I have seen. Ok it does not yet seem to make my breakfast, but the rest of the claims seem more than justified. Even without updating the splash screen support to use Plymouth we were seeing a vastly less blinky boot sequence and resume from suspend which seemed almost instant, the screensaver lock being visible in the time it took me to open the lid.

There is a lot of work still to do of course. This is all very fragile only supporting Intel hardware as I write. We do hope to have at least ATI support before Karmic Koala is released (though that depends on how quickly radeon support gets merged). Also getting the right bits together is non-trivial. You need an appropriate kernel, updated X and mesa, some manual configuration etc. But we are planning to put together a PPA with the required bits and document things better. Watch out for further announcements.


  1. Can you provide info on how to enable KMS for us feature hungry addicts?

  2. @Colin

    Its documented here: