Re: [PATCH v8 3/6] cpufreq: powernv: Remove cpu_to_chip_id() from hot-path

 static int nr_chips;
+static DEFINE_PER_CPU(unsigned int, chip_id);
 
 /*
  * Note: The set of pstates consists of contiguous integers, the

@@ -317,9 +318,7 @@ static void powernv_cpufreq_throttle_check(void

*data)
 
        pmsr = get_pmspr(SPRN_PMSR);
 
-       for (i = 0; i < nr_chips; i++)
-               if (chips[i].id == cpu_to_chip_id(cpu))
-                       break;
+       i = this_cpu_read(chip_id);

        /* Check for Pmax Capping */
        pmsr_pmax = (s8)PMSR_MAX(pmsr);

@@ -560,6 +559,7 @@ static int init_chip_info(void)

        for_each_possible_cpu(cpu) {
                unsigned int id = cpu_to_chip_id(cpu);
 
+               per_cpu(chip_id, cpu) = nr_chips;
                if (prev_chip_id != id) {
                        prev_chip_id = id;
                        chip[nr_chips++] = id;
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