Messages in this thread |  | | Date | Sun, 7 Oct 2001 16:24:39 +0200 | From | Ingo Oeser <> | Subject | Re: Context switch times |
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On Sun, Oct 07, 2001 at 04:48:30PM +0300, Mika Liljeberg wrote: > Ingo Oeser wrote: > > The idle-task might be (ab-)used for this, because it has perfect > > data for this. > > > > T_SystemElapsed - T_IdleTaskRun = T_CPULoaded > > The problem here is that the idle task doesn't get run at all if there > are runnable tasks.
There are idle tasks per CPU. If there are runnable tasks and the idle-task of a CPU is running it, it is not fully loaded at this time.
No idle task is running, if all CPUs are fully loaded AFAIR.
> One interesting property of the load balancer tasks would be that the > less heavily loaded CPUs would tend to execute the load balancer more > often, actively releaving the more heavily loaded CPUs, while those > would concentrate more on getting the job done. Come to think of it, it > could be coded in such a way that only the least loaded CPU would > execute the load balancing algorithm, while the others would simply > chalk up elapsed times.
So you suggest only one load balancer task jumping from CPU to CPU. I misunderstood it. _Only_ chalking up could certainly done by the idle tasks.
Regards
Ingo Oeser - 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/
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