Messages in this thread | | | Subject | Re: [PATCH 4/6] sched/fair: Name utilization related data and functions consistently | From | Dietmar Eggemann <> | Date | Fri, 11 Sep 2015 17:35:55 +0100 |
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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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