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    SubjectRe: [PATCH 4/6] sched/fair: Name utilization related data and functions consistently
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    On 04/09/15 10:08, Vincent Guittot wrote:
    > On 14 August 2015 at 18:23, Morten Rasmussen <morten.rasmussen@arm.com> wrote:
    >> From: Dietmar Eggemann <dietmar.eggemann@arm.com>
    >>
    >> Use the advent of the per-entity load tracking rewrite to streamline the
    >> naming of utilization related data and functions by using
    >> {prefix_}util{_suffix} consistently. Moreover call both signals
    >> ({se,cfs}.avg.util_avg) utilization.
    >
    > I don't have a strong opinion about the naming of this variable but I
    > remember a discussion about this topic:
    > https://lkml.org/lkml/2014/9/11/474 : "Call the pure running number
    > 'utilization' and this scaled with capacity 'usage' "
    >
    > The utilization has been shorten to util with the rewrite of the pelt,
    > so the current use of usage in get_cpu_usage still follows this rule.

    But since we now do the capacity scaling in __update_load_avg()

    util_sum += t * scale_freq/SCHED_CAP_SCALE * arch_scale_freq_capacity()

    util_avg = util_sum / LOAD_AVG_MAX;

    we could either name everything 'util' or everything 'usage' (including
    the utilization sum and avg in struct sched_avg).

    >
    > So why do you want to change that now ?
    > Furthermore, cfs.avg.util_avg is a load whereas sgs->group_util is a
    > capacity. Both don't use the same unit and same range which can be
    > confusing when you read the code

    [...]



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