Messages in this thread | | | Date | Wed, 10 Oct 2018 14:11:26 +0100 | From | Quentin Perret <> | Subject | Re: [RFC PATCH 0/7] Introduce thermal pressure |
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On Wednesday 10 Oct 2018 at 14:50:33 (+0200), Juri Lelli wrote: > On 10/10/18 14:34, Vincent Guittot wrote: > > Hi Juri, > > > > On Wed, 10 Oct 2018 at 14:23, Juri Lelli <juri.lelli@gmail.com> wrote: > > > > > > On 10/10/18 14:04, Vincent Guittot wrote: > > > > > > [...] > > > > > > > The problem was the same with RT, the cfs utilization was lower than > > > > reality because RT steals soem cycle to CFS > > > > So schedutil was selecting a lower frequency when cfs was running > > > > whereas the CPU was fully used. > > > > The same can happen with thermal: > > > > cap the max freq because of thermal > > > > the utilization with decrease. > > > > remove the cap > > > > the utilization is still low and you will select a low OPP because you > > > > don't take into account cycle stolen by thermal like with RT > > > > > > What if we scale frequency component considering the capped temporary > > > max? > > > > Do you mean using a kind of scale_thermal_capacity in accumulate_sum > > when computing utilization ? > > Yeah, something like that I guess. So that we account for temporary > "fake" 1024..
But wouldn't that break frequency invariance ? A task would look bigger on a capped CPU than a non-capped one no ?
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