Kernel solipsism

Thomas Gleixner:

Exactly that's the point. Adding dom0 makes life easier for a group of users who decided to use Xen some time ago, but what Ingo wants is technical improvement of the kernel... The kernel policy always was and still is to accept only those features which have a technical benefit to the code base.

It boggles the mind that someone could get things so backwards. The kernel exists to provide services to the outside world, not the other way around. By all means criticise the details of the Xen dom0 code, but this argument makes zero sense. How precisely did x86_64 support provide a technical benefit to the code base?


Matthew Garrett said...

x86_64 imposed no significant cost (in terms of run-time performance or code complexity) on the rest of the kernel. Xen adds extra complexity to code used by a large number of people but benefits a significantly smaller number of people. The cost/benefit ratios of the two are almost directly opposite.

John Levon said...

You haven't answered the question, Matthew. I wasn't asking about costs (I'm more aware than many on how Xen support impacts kernel complexity).