RE: [PATCH V8 3/7] cpufreq: amd-pstate: Enable amd-pstate preferred core supporting.

[AMD Official Use Only - General]

Hi Peter:

-----Original Message----- From: Peter Zijlstra peterz@infradead.org Sent: Tuesday, October 10, 2023 6:36 PM To: Meng, Li (Jassmine) Li.Meng@amd.com Cc: Rafael J . Wysocki rafael.j.wysocki@intel.com; Huang, Ray Ray.Huang@amd.com; linux-pm@vger.kernel.org; linux- kernel@vger.kernel.org; x86@kernel.org; linux-acpi@vger.kernel.org; Shuah Khan skhan@linuxfoundation.org; linux-kselftest@vger.kernel.org; Fontenot, Nathan Nathan.Fontenot@amd.com; Sharma, Deepak Deepak.Sharma@amd.com; Deucher, Alexander Alexander.Deucher@amd.com; Limonciello, Mario Mario.Limonciello@amd.com; Huang, Shimmer Shimmer.Huang@amd.com; Yuan, Perry Perry.Yuan@amd.com; Du, Xiaojian Xiaojian.Du@amd.com; Viresh Kumar viresh.kumar@linaro.org; Borislav Petkov bp@alien8.de Subject: Re: [PATCH V8 3/7] cpufreq: amd-pstate: Enable amd-pstate preferred core supporting.

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On Mon, Oct 09, 2023 at 10:49:28AM +0800, Meng Li wrote:

...

+static void amd_pstate_init_prefcore(struct amd_cpudata *cpudata) {

• int ret;
  

• u32 highest_perf;
  

• static u32 max_highest_perf = 0, min_highest_perf = U32_MAX;
  

• ret = amd_pstate_get_highest_perf(cpudata->cpu, &highest_perf);
  

• if (ret)
  

•         return;
  

• cpudata->hw_prefcore = true;
  

• /* check if CPPC preferred core feature is enabled*/
  

• if (highest_perf == AMD_PSTATE_MAX_CPPC_PERF) {
  

•         pr_debug("AMD CPPC preferred core is unsupported!\n");
  

•         cpudata->hw_prefcore = false;
  

•         return;
  

• }
  

• if (!amd_pstate_prefcore)
  

•         return;
  

• /*
  

•  * The priorities can be set regardless of whether or not
  

•  * sched_set_itmt_support(true) has been called and it is valid to
  

•  * update them at any time after it has been called.
  

•  */
  

• sched_set_itmt_core_prio(highest_perf, cpudata->cpu);
  

You still got the whole u32 vs int thing confused, I've only pointed that out *TWICE* before.

Boris, can you pull out the clue hammer please?

[Meng, Li (Jassmine)] I feel very sorry, I will immediately double check and correct all modified data type. Thanks a lot.

...

• if (max_highest_perf <= min_highest_perf) {
  

•         if (highest_perf > max_highest_perf)
  

•                 max_highest_perf = highest_perf;
  

•         if (highest_perf < min_highest_perf)
  

•                 min_highest_perf = highest_perf;
  

•         if (max_highest_perf > min_highest_perf) {
  

•                 /*
  

•                  * This code can be run during CPU online under the
  

•                  * CPU hotplug locks, so sched_set_itmt_support()
  

•                  * cannot be called from here.  Queue up a work item
  

•                  * to invoke it.
  

•                  */
  

•                 schedule_work(&sched_prefcore_work);
  

•         }
  

• }
  

+}