On Mon, Dec 18, 2017 at 5:59 AM, Viresh Kumar <viresh.ku...@linaro.org> wrote: > On 17-12-17, 01:19, Rafael J. Wysocki wrote: >> We can do that in principle, but why should it return early? Maybe it's >> a good time to update things, incidentally? >> >> I actually don't like the SCHED_CPUFRREQ_CLEAR flag *concept* as it is very >> much specific to schedutil and blatantly ignores everybody else. >> >> Alternatively, you could add two flags for clearing SCHED_CPUFREQ_RT and >> SCHED_CPUFREQ_DL that could just be ingored entirely by intel_pstate. >> >> So, why don't you make SCHED_CPUFREQ_RT and SCHED_CPUFREQ_DL "sticky" until, >> say, SCHED_CPUFREQ_NO_RT and SCHED_CPUFREQ_NO_DL are passed, respectively? > > I didn't like adding scheduling class specific flags, and wanted the code to > treat all of them in the same way. And then the governors can make a policy > over > that, on what to ignore and what not to. For example with the current > patchset, > the governors can know when nothing else is queued on a CPU and CPU is going > to > get into idle loop. They can choose to (or not to) do something in that case.
Well, if SCHED_CPUFRREQ_CLEAR means "this CPU is going to enter the idle loop" really, then it is better to call it SCHED_CPUFRREQ_ENTER_IDLE, for example. SCHED_CPUFRREQ_CLEAR meaning basically "you should clear these flags now" doesn't seem to convey any information to whoever doesn't squirrel the flags in the first place.
