On 28/05/18 14:06, Vincent Guittot wrote: > Hi Juri, > > On 28 May 2018 at 12:41, Juri Lelli <juri.le...@redhat.com> wrote: > > Hi Vincent, > > > > On 25/05/18 15:12, Vincent Guittot wrote: > >> The time spent under interrupt can be significant but it is not reflected > >> in the utilization of CPU when deciding to choose an OPP. Now that we have > >> access to this metric, schedutil can take it into account when selecting > >> the OPP for a CPU. > >> The CPU utilization is : > >> irq util_avg + (1 - irq util_avg / max capacity ) * /Sum rq util_avg > > > > IIUC the code below you actually propose that > > > > util = [(max_cap - util_irq) * util_rq] / max_cap + util_irq > > > > where > > > > util_rq = /Sum rq util_avg > > util_irq = irq util_avg > > > > So, which one is what you have in mind? Or am I wrong? :) > > mmh ... aren't they equal ? > > util = [(max_cap - util_irq) * util_rq] / max_cap + util_irq > util = [(max_cap/max_cap - util_irq/max_cap) * util_rq] + util_irq > util = [(1 - util_irq/max_cap) * util_rq] + util_irq > util = util_irq + [(1 - util_irq/max_cap) * util_rq]
Ah, indeed.