Commit 78e27086 authored Jul 18, 2014 by Stratos Karafotis Committed by Rafael J. Wysocki Jul 21, 2014

cpufreq: intel_pstate: Remove core_pct rounding



The specific rounding adds conditionally only 1/256 to fractional
part of core_pct.

We can safely remove it without any noticeable impact in
calculations.

Use div64_u64 instead of div_u64 to avoid possible overflow of
sample->mperf as divisor

Signed-off-by: Stratos Karafotis <stratosk@semaphore.gr>
Signed-off-by: Dirk Brandewie <dirk.j.brandewie@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

parent 4b707c89

drivers/cpufreq/intel_pstate.c

+1 −5

Original line number	Diff line number	Diff line
		@@ -545,13 +545,9 @@ static inline void intel_pstate_calc_busy(struct cpudata *cpu)
		{
		struct sample *sample = &cpu->sample;
		int64_t core_pct;
		int32_t rem;

		core_pct = int_tofp(sample->aperf) * int_tofp(100);
		core_pct = div_u64_rem(core_pct, int_tofp(sample->mperf), &rem);

		if ((rem << 1) >= int_tofp(sample->mperf))
		core_pct += 1;
		core_pct = div64_u64(core_pct, int_tofp(sample->mperf));

		sample->freq = fp_toint(
		mul_fp(int_tofp(cpu->pstate.max_pstate * 1000), core_pct));