default cpufreq gov, was: [PATCH] sched/fair: check for idle core

[Peter Zijlstra]

On Thu, Oct 22, 2020 at 01:45:25PM +0200, Rafael J. Wysocki wrote:
> On Thursday, October 22, 2020 12:47:03 PM CEST Viresh Kumar wrote:
> > On 22-10-20, 09:11, Peter Zijlstra wrote:
> > > Well, but we need to do something to force people onto schedutil,
> > > otherwise we'll get more crap like this thread.
> > > 
> > > Can we take the choice away? Only let Kconfig select which governors are
> > > available and then set the default ourselves? I mean, the end goal being
> > > to not have selectable governors at all, this seems like a good step
> > > anyway.
> > 
> > Just to clarify and complete the point a bit here, the users can still
> > pass the default governor from cmdline using
> > cpufreq.default_governor=, which will take precedence over the one the
> > below code is playing with. And later once the kernel is up, they can
> > still choose a different governor from userspace.
> 
> Right.
> 
> Also some people simply set "performance" as the default governor and then
> don't touch cpufreq otherwise (the idea is to get everything to the max
> freq right away and stay in that mode forever).  This still needs to be
> possible IMO.

Performance/powersave make sense to keep.

However I do want to retire ondemand, conservative and also very much
intel_pstate/active mode. I also have very little sympathy for
userspace.

We should start by making it hard to use them and eventually just delete
them outright.