Re: Stolen and degraded time and schedulers

[Jeremy Fitzhardinge]

Daniel Walker wrote:
> Then your direction is wrong, sched_clock() should be constant ideally
> (1millisecond should really be 1millisecond). 

Rather than repeating myself, I suggest you read my original post
again.  But my point is that "I was runnable on a cpu for 1ms of real
time" is a meaningless measurement: you want to measure "I ran for 1
cpu-ms", which is a unit which depends on how work a particular CPU does
in relationship to other CPUs on the system, or even itself at some
previous time.

> Like I said in the last
> email, change the scheduler to make it aware of the variable quantum
> values.

I suppose you could, but that seems more complex.  I think you could
encode the same information in the measurement of how much work a cpu
actually got done while a process was scheduled on it.

    J
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/