Re: [PATCH V5 3/7] cpufreq: amd-pstate: Enable amd-pstate preferred core supporting.

On Tue, Sep 05, 2023 at 09:51:12AM +0800, Meng Li wrote:

+static void amd_pstate_init_prefcore(void) +{

• int cpu, ret;
• u64 highest_perf;
• if (!prefcore)

• return;
  

• for_each_online_cpu(cpu) {

• ret = amd_pstate_get_highest_perf(cpu, &highest_perf);
  

• if (ret)
  

• 	break;
  

• sched_set_itmt_core_prio(highest_perf, cpu);
  

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

• if (highest_perf == AMD_PSTATE_MAX_CPPC_PERF) {
  

• 	hw_prefcore = false;
  

• 	prefcore = false;
  

• 	return;
  

• }
  

• }
• /*

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

• * CPU hotplug locks, so sched_set_amd_prefcore_support()
  

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

• * to invoke it.
  

• */
  

• schedule_work(&sched_prefcore_work);

+}

@@ -1506,6 +1593,8 @@ static int __init amd_pstate_init(void) } }

• amd_pstate_init_prefcore();
• return ret;

global_attr_free:

I'm confused,... you call amd_pstate_init_prefcore() at device_initcall(). Once per boot.

Then it iterates all online CPUs..

But what if you boot with some CPUs offline and bring then online later?