On Tue, Dec 27, 2022 at 7:49 PM srinivas pandruvada <srinivas.pandruvada@xxxxxxxxxxxxxxx> wrote: > > On Tue, 2022-12-27 at 19:47 +0100, Rafael J. Wysocki wrote: > > On Tue, Dec 27, 2022 at 7:07 PM srinivas pandruvada > > <srinivas.pandruvada@xxxxxxxxxxxxxxx> wrote: > > > > > > On Tue, 2022-12-27 at 18:02 +0100, Rafael J. Wysocki wrote: > > > > On Tue, Dec 27, 2022 at 5:40 PM srinivas pandruvada > > > > <srinivas.pandruvada@xxxxxxxxxxxxxxx> wrote: > > > > > > > > > > On Tue, 2022-12-27 at 16:38 +0100, Pratyush Yadav wrote: > > > > > > Hi Srinivas, > > > > > > > > > > > > On Sat, Dec 24 2022, srinivas pandruvada wrote: > > > > > > > > > > > > > On Fri, 2022-12-23 at 10:10 -0800, srinivas pandruvada > > > > > > > wrote: > > > > > > > > Hi Pratyush, > > > > > > > > > > > > > > > > On Thu, 2022-12-22 at 11:39 +0100, Pratyush Yadav wrote: > > > > > > > > > > > > > > > > > > Hi Srinivas, > > > > > > > > > > > > > > > > > > On Wed, Dec 21 2022, srinivas pandruvada wrote: > > > > > > > > > > On Wed, 2022-12-21 at 16:52 +0100, Pratyush Yadav > > > > > > > > > > wrote: > > > > > > > > > > > When a processor is brought offline and online > > > > > > > > > > > again, > > > > > > > > > > > it is > > > > > > > > > > > unable to > > > > > > > > > > > use Turbo mode because the _PSS table does not > > > > > > > > > > > contain > > > > > > > > > > > the > > > > > > > > > > > whole > > > > > > > > > > > turbo > > > > > > > > > > > frequency range, but only +1 MHz above the max non- > > > > > > > > > > > turbo > > > > > > > > > > > frequency. > > > > > > > > > > > This > > > > > > > > > > > causes problems when ACPI processor driver tries to > > > > > > > > > > > set > > > > > > > > > > > frequency > > > > > > > > > > > constraints. See patch 2 for more details. > > > > > > > > > > > > > > > > > > > I can reproduce on a Broadwell server platform. But not > > > > > > > > on a > > > > > > > > client > > > > > > > > system with acpi_ppc usage. > > > > > > > > > > > > > > > > Need to check what change broke this. > > > > > > > > > > > > > > When PPC limits enforcement changed to PM QOS, this broke. > > > > > > > Previously > > > > > > > acpi_processor_get_platform_limit() was not enforcing any > > > > > > > limits. > > > > > > > It > > > > > > > was just setting variable. So any update done after > > > > > > > acpi_register_performance_state() call to pr->performance- > > > > > > > > states[ppc].core_frequency, was effective. > > > > > > > > > > > > > > We don't really need to call > > > > > > > ret = freq_qos_update_request(&pr->perflib_req, > > > > > > > pr->performance- > > > > > > > > states[ppc].core_frequency > > > > > > > * > > > > > > > 1000); > > > > > > > > > > > > > > if the PPC is not changed. When PPC is changed, this gets > > > > > > > called > > > > > > > again, > > > > > > > so then we can call the above function to update cpufreq > > > > > > > limit. > > > > > > > > > > > > > > The below change fixed for me. > > > > > > > > > > > > Right. > > > > > I think, this is the only change you require to fix this. In > > > > > addition > > > > > set pr->performance_platform_limit = 0 in > > > > > acpi_processor_unregister_performance(). > > > > > > > > Not really, because if the limit is set to a lower frequency and > > > > then > > > > reset to _PSS[0], it needs to be set back to "no limit". > > > > > > > > > > If PPC becomes 0 again after ppc > 0 during dynamic PPC change, pr- > > > > performance_platform_limit will not match current PPC, so will > > > > set to > > > PPC 0 performance ( which is already patched by driver after return > > > from acpi_register_performance_state()). > > > > I see. > > > > > But fine, you can always set freq qos to FREQ_QOS_MAX_DEFAULT_VALUE > > > for > > > PPC 0 as you are doing in your patch. > > > > I think that using the "no limit" value to represent the "no limit" > > condition makes sense. > Agree. > > > > > Also, I'm wondering if the patching of states[0].core_frequency will > > still be necessary after this change. > > I don't think so. We can remove the patching. OK, let me cut the patches.
