On 2014/2/13 2:01, dirk.brande...@gmail.com wrote:
> From: Dirk Brandewie <dirk.j.brande...@intel.com>
>
> 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.brande...@intel.com>
> ---
> drivers/cpufreq/intel_pstate.c | 25 ++++++++++++-------------
> 1 file changed, 12 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
> index c788abf..d692b10 100644
> --- a/drivers/cpufreq/intel_pstate.c
> +++ b/drivers/cpufreq/intel_pstate.c
> @@ -96,8 +96,7 @@ 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;
> @@ -570,15 +569,15 @@ static inline void intel_pstate_sample(struct cpudata
> *cpu)
> rdmsrl(MSR_IA32_MPERF, mperf);
> tsc = native_read_tsc();
To be pikcy, just want the ratio more accurate, since aperf and mperf
are a pair, do you want to turn interrupt off to make sure nothing
occurs between reading aperf and mperf? and since native_read_tsc() is
called here, better to put into no interrupt context as well.
Thanks,
-Aubrey
>
> - 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;
>
> - intel_pstate_calc_busy(cpu, &cpu->samples[cpu->sample_ptr]);
> + 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->sample);
>
> cpu->prev_aperf = aperf;
> cpu->prev_mperf = mperf;
> @@ -598,7 +597,7 @@ 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);
> return mul_fp(core_busy, div_fp(max_pstate, current_pstate));
> @@ -631,7 +630,7 @@ 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);
>
> @@ -712,7 +711,7 @@ 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;
> }
>
>
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