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    SubjectRe: [PATCH (updated)] timer: Run calc_load halfway through each round_jiffies second
    On Thu, Mar 01, 2007 at 10:52:01PM +0000, Simon Arlott wrote:
    > Whenever jiffies is started at a multiple of 5*HZ or wraps, calc_load is
    > run exactly on the second which is when tasks using round_jiffies will
    > be scheduled to run. This has a bad effect on the load average, making
    > it tend towards 1.00 if a task happens to run every time the load is
    > being calculated.
    > This changes calc_load so that it updates load half a second after any
    > tasks scheduled using round_jiffies.
    > Signed-off-by: Simon Arlott <simon@fire.lp0.eu>
    > Cc: Andrew Morton <akpm@linux-foundation.org>
    > Cc: Arjan van de Ven <arjan@linux.intel.com>

    Well, it doesn't reintroduce the for_each_task() (not that it's present
    in similar form) loop in count_active_tasks(), so it doesn't bother me.
    You seem to have merely changed some offsets, which resolves the
    round_jiffies() clash. It's easy to envision similar degenerate cases,
    though I'm not sure we care enough to drop in a PRNG to handle them.


    == wli
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