Messages in this thread | | | Date | Mon, 14 May 2007 20:32:34 +0530 | From | Srivatsa Vaddagiri <> | Subject | Re: fair clock use in CFS |
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On Mon, May 14, 2007 at 10:31:13AM -0400, Daniel Hazelton wrote: > Hrm... Okay, so you're saying that "fair_clock" runs slower the more process > there are running to keep the above run-up in "Time Spent on CPU" I noticed > based solely on your initial example? If that is the case, then I can see the > fairness - its just not visible from a really quick look at the code and the > simplified description you gave earlier.
From the code:
update_curr()
delta_fair = delta_exec * NICE_0_LOAD; do_div(delta_fair, rq->raw_weighted_load);
..
rq->fair_clock += delta_fair;
Although wall clock would have advanced by delta_exec, fair clock advances only by delta_fair.
More the load on the CPU (rq->raw_weighted_load), slower is this advance compared to wall clock.
-- Regards, vatsa - 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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