The patch below does not apply to the 3.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable@xxxxxxxxxxxxxxx>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From fcb6a15c2e7e76d493e6f91ea889ab40e1c643a4 Mon Sep 17 00:00:00 2001 From: Dirk Brandewie <dirk.j.brandewie@xxxxxxxxx> Date: Mon, 3 Feb 2014 08:55:31 -0800 Subject: [PATCH] intel_pstate: Take core C0 time into account for core busy calculation Take non-idle time into account when calculating core busy time. This ensures that intel_pstate will notice a decrease in load. References: https://bugzilla.kernel.org/show_bug.cgi?id=66581 Cc: 3.10+ <stable@xxxxxxxxxxxxxxx> # 3.10+ Signed-off-by: Dirk Brandewie <dirk.j.brandewie@xxxxxxxxx> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c index 7e257b233602..79606f473f48 100644 --- a/drivers/cpufreq/intel_pstate.c +++ b/drivers/cpufreq/intel_pstate.c @@ -57,6 +57,7 @@ struct sample { int32_t core_pct_busy; u64 aperf; u64 mperf; + unsigned long long tsc; int freq; }; @@ -96,6 +97,7 @@ struct cpudata { u64 prev_aperf; u64 prev_mperf; + unsigned long long prev_tsc; int sample_ptr; struct sample samples[SAMPLE_COUNT]; }; @@ -548,30 +550,41 @@ static inline void intel_pstate_calc_busy(struct cpudata *cpu, struct sample *sample) { u64 core_pct; - core_pct = div64_u64(int_tofp(sample->aperf * 100), - sample->mperf); - sample->freq = fp_toint(cpu->pstate.max_pstate * core_pct * 1000); + u64 c0_pct; - sample->core_pct_busy = core_pct; + core_pct = div64_u64(sample->aperf * 100, sample->mperf); + + c0_pct = div64_u64(sample->mperf * 100, sample->tsc); + sample->freq = fp_toint( + mul_fp(int_tofp(cpu->pstate.max_pstate), + int_tofp(core_pct * 1000))); + + sample->core_pct_busy = mul_fp(int_tofp(core_pct), + div_fp(int_tofp(c0_pct + 1), int_tofp(100))); } static inline void intel_pstate_sample(struct cpudata *cpu) { u64 aperf, mperf; + unsigned long long tsc; rdmsrl(MSR_IA32_APERF, aperf); rdmsrl(MSR_IA32_MPERF, mperf); + tsc = native_read_tsc(); 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->prev_aperf = aperf; cpu->prev_mperf = mperf; + cpu->prev_tsc = tsc; } static inline void intel_pstate_set_sample_time(struct cpudata *cpu) -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html