intel_pstate: Update cpu_frequency tracepoint every time
authorRafael J. Wysocki <rafael.j.wysocki@intel.com>
Tue, 19 Jul 2016 13:10:37 +0000 (15:10 +0200)
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>
Thu, 21 Jul 2016 12:28:37 +0000 (14:28 +0200)
Currently, intel_pstate only updates the cpu_frequency tracepoint
if the new P-state to set is different from the current one, but
that causes powertop to report 100% idle on an 100% loaded system
sometimes.

Prevent that from happening by updating the cpu_frequency tracepoint
every time intel_pstate_update_pstate() is called.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>-
drivers/cpufreq/intel_pstate.c

index edb3b69..9c8a78f 100644 (file)
@@ -1132,17 +1132,12 @@ static void intel_pstate_get_min_max(struct cpudata *cpu, int *min, int *max)
        *min = clamp_t(int, min_perf, cpu->pstate.min_pstate, max_perf);
 }
 
-static inline void intel_pstate_record_pstate(struct cpudata *cpu, int pstate)
-{
-       trace_cpu_frequency(pstate * cpu->pstate.scaling, cpu->cpu);
-       cpu->pstate.current_pstate = pstate;
-}
-
 static void intel_pstate_set_min_pstate(struct cpudata *cpu)
 {
        int pstate = cpu->pstate.min_pstate;
 
-       intel_pstate_record_pstate(cpu, pstate);
+       trace_cpu_frequency(pstate * cpu->pstate.scaling, cpu->cpu);
+       cpu->pstate.current_pstate = pstate;
        /*
         * Generally, there is no guarantee that this code will always run on
         * the CPU being updated, so force the register update to run on the
@@ -1302,10 +1297,11 @@ static inline void intel_pstate_update_pstate(struct cpudata *cpu, int pstate)
 
        intel_pstate_get_min_max(cpu, &min_perf, &max_perf);
        pstate = clamp_t(int, pstate, min_perf, max_perf);
+       trace_cpu_frequency(pstate * cpu->pstate.scaling, cpu->cpu);
        if (pstate == cpu->pstate.current_pstate)
                return;
 
-       intel_pstate_record_pstate(cpu, pstate);
+       cpu->pstate.current_pstate = pstate;
        wrmsrl(MSR_IA32_PERF_CTL, pstate_funcs.get_val(cpu, pstate));
 }