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    SubjectRe: [rfc patch] sched/fair: Use instantaneous load for fork/exec balancing
    On Tue, Jun 14, 2016 at 09:58:31AM +0200, Mike Galbraith wrote:
    > SUSE's regression testing noticed that...
    >
    > 0905f04eb21f sched/fair: Fix new task's load avg removed from source CPU in wake_up_new_task()
    >
    > ...introduced a hackbench regression, and indeed it does. I think this
    > regression has more to do with randomness than anything else, but in
    > general...
    >
    > While averaging calms down load balancing, helping to keep migrations
    > down to a dull roar, it's not completely wonderful when it comes to
    > things that live in the here and now, hackbench being one such.
    >
    > time sh -c 'for i in `seq 1000`; do hackbench -p -P > /dev/null; done'
    >
    > real 0m55.397s
    > user 0m8.320s
    > sys 5m40.789s
    >
    > echo LB_INSTANTANEOUS_LOAD > /sys/kernel/debug/sched_features
    >
    > real 0m48.049s
    > user 0m6.510s
    > sys 5m6.291s
    >
    > Signed-off-by: Mike Galbraith <umgwanakikbuti@gmail.com>

    I am entirely for giving it a "clear unadulterated reality", and even
    more for it an option.

    Reviewed-by: Yuyang Du <yuyang.du@intel.com>

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