It has nothing to do with hardware. The over head is putting a timer
entry in the list and then removing it. Almost all timers are canceled
before they expire. Even with the O(1) timer list, this takes time and
when done at the context switch rate the time mounts rapidly. And we
need at least one timer when we switch to a task. In the test code I
only start a "slice" timer. This means that a task that wants a
execution time signal may find the signal delayed by as much as a slice,
but it does keep the overhead lower.
>
> Anton
-- George Anzinger george@mvista.com High-res-timers: http://sourceforge.net/projects/high-res-timers/ Real time sched: http://sourceforge.net/projects/rtsched/ Preemption patch: http://www.kernel.org/pub/linux/kernel/people/rml - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/