intel_pstate: remove unneeded sample buffers

commit d37e2b764499e092ebc493d6f980827feb952e23 upstream.

Remove unneeded sample buffers, intel_pstate operates on the most
recent sample only.  This save some memory and make the code more
readable.

Signed-off-by: Dirk Brandewie <dirk.j.brandewie@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index 9ac3783..781e2ea 100644 (file)
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -101,8 +101,7 @@ struct cpudata {
        u64     prev_aperf;
        u64     prev_mperf;
        unsigned long long prev_tsc;
-       int     sample_ptr;
-       struct sample samples[SAMPLE_COUNT];
+       struct sample sample;
 };
 
 static struct cpudata **all_cpu_data;
@@ -590,15 +589,14 @@ static inline void intel_pstate_sample(struct cpudata *cpu)
        mperf = mperf >> FRAC_BITS;
        tsc = tsc >> FRAC_BITS;
 
-       cpu->sample_ptr = (cpu->sample_ptr + 1) % SAMPLE_COUNT;
-       cpu->samples[cpu->sample_ptr].aperf = aperf;
-       cpu->samples[cpu->sample_ptr].mperf = mperf;
-       cpu->samples[cpu->sample_ptr].tsc = tsc;
-       cpu->samples[cpu->sample_ptr].aperf -= cpu->prev_aperf;
-       cpu->samples[cpu->sample_ptr].mperf -= cpu->prev_mperf;
-       cpu->samples[cpu->sample_ptr].tsc -= cpu->prev_tsc;
+       cpu->sample.aperf = aperf;
+       cpu->sample.mperf = mperf;
+       cpu->sample.tsc = tsc;
+       cpu->sample.aperf -= cpu->prev_aperf;
+       cpu->sample.mperf -= cpu->prev_mperf;
+       cpu->sample.tsc -= cpu->prev_tsc;
 
-       intel_pstate_calc_busy(cpu, &cpu->samples[cpu->sample_ptr]);
+       intel_pstate_calc_busy(cpu, &cpu->sample);
 
        cpu->prev_aperf = aperf;
        cpu->prev_mperf = mperf;
@@ -618,7 +616,7 @@ static inline int32_t intel_pstate_get_scaled_busy(struct cpudata *cpu)
 {
        int32_t core_busy, max_pstate, current_pstate;
 
-       core_busy = cpu->samples[cpu->sample_ptr].core_pct_busy;
+       core_busy = cpu->sample.core_pct_busy;
        max_pstate = int_tofp(cpu->pstate.max_pstate);
        current_pstate = int_tofp(cpu->pstate.current_pstate);
        core_busy = mul_fp(core_busy, div_fp(max_pstate, current_pstate));
@@ -652,7 +650,7 @@ static void intel_pstate_timer_func(unsigned long __data)
 
        intel_pstate_sample(cpu);
 
-       sample = &cpu->samples[cpu->sample_ptr];
+       sample = &cpu->sample;
 
        intel_pstate_adjust_busy_pstate(cpu);
 
@@ -727,7 +725,7 @@ static unsigned int intel_pstate_get(unsigned int cpu_num)
        cpu = all_cpu_data[cpu_num];
        if (!cpu)
                return 0;
-       sample = &cpu->samples[cpu->sample_ptr];
+       sample = &cpu->sample;
        return sample->freq;
 }