Re: [2.4.17/18pre] VM and swap - it's really unusable

Robert Love
2002-01-09T00:41:32Z

On Tue, 2002-01-08 at 19:29, John Alvord wrote:

> The best part about planned preemption points is that there is minimal
> state to save when an interruption occurs.

Actually, both preempt-kernel and low-latency do about the same amount
of work re saving state.

With preempt-kernel, when a task is preempted in-kernel we AND a flag
value into the preempt count. That is all we need to keep track of
things.

With low-latency, the task state is set to TASK_RUNNING (which is a
precautionary measure). So it is about the same, although low-latency
(and lock-break) often also have to do various setup with the locks and
all.

Robert Love