On 25-10-19, 10:17, Rafael J. Wysocki wrote: > On Fri, Oct 25, 2019 at 4:53 AM Viresh Kumar <viresh.kumar@xxxxxxxxxx> wrote: > > > > On 25-10-19, 02:41, Rafael J. Wysocki wrote: > > > From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> > > > > > > The _PPC change notifications from the platform firmware are per-CPU, > > > so acpi_processor_ppc_init() needs to add a frequency QoS request > > > for each CPU covered by a cpufreq policy to take all of them into > > > account. > > > > > > Even though ACPI thermal control of CPUs sets frequency limits > > > per processor package, it also needs a frequency QoS request for each > > > CPU in a cpufreq policy in case some of them are taken offline and > > > the frequency limit needs to be set through the remaining online > > > ones (this is slightly excessive, because all CPUs covered by one > > > cpufreq policy will set the same frequency limit through their QoS > > > requests, but it is not incorrect). > > > > > > Modify the code in accordance with the above observations. > > > > I am not sure if I understood everything you just said, but I don't > > see how things can break with the current code we have. > > > > Both acpi_thermal_cpufreq_init() and acpi_processor_ppc_init() are > > called from acpi_processor_notifier() which is registered as a policy > > notifier and is called when a policy is created or removed. Even if > > some CPUs of a policy go offline, it won't matter as the request for > > the policy stays and it will be dropped only when all the CPUs of a > > policy go offline. > > > > What am I missing ? > > The way the request is used. Yes, I missed the point :) -- viresh
