Messages in this thread | | | Date | Fri, 25 Oct 2019 08:23:43 +0530 | From | Viresh Kumar <> | Subject | Re: [PATCH] ACPI: processor: Add QoS requests for all CPUs |
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On 25-10-19, 02:41, Rafael J. Wysocki wrote: > From: Rafael J. Wysocki <rafael.j.wysocki@intel.com> > > 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 ?
-- viresh
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