Messages in this thread Patch in this message | | | From | Doug Smythies <> | Subject | [Resend][PATCH V2] cpufreq: intel_pstate: allow trace in passive mode | Date | Fri, 15 Dec 2017 16:43:00 -0800 |
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Allow use of the trace_pstate_sample trace function when the intel_pstate driver is in passive mode. Since the core_busy and scaled_busy fields are not used, and it might be desirable to know which path through the driver was used, either intel_cpufreq_target or intel_cpufreq_fast_switch, re-task the core_busy field as a flag indicator.
The user can then use the intel_pstate_tracer.py utility to summarize and plot the trace.
In Passive mode the driver is only called if there is a need to change the target frequency, so durations (time gaps between calls) can be very very long. The user needs to understand, and not be confused by, this limitation.
V2: prepare for resend. Rebase to current kernel, 4.15-rc3. Signed-off-by: Doug Smythies <dsmythies@telus.net> --- drivers/cpufreq/intel_pstate.c | 50 ++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 48 insertions(+), 2 deletions(-)
diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c index 93a0e88..fe25d69 100644 --- a/drivers/cpufreq/intel_pstate.c +++ b/drivers/cpufreq/intel_pstate.c @@ -1949,7 +1949,10 @@ static int intel_cpufreq_target(struct cpufreq_policy *policy, { struct cpudata *cpu = all_cpu_data[policy->cpu]; struct cpufreq_freqs freqs; - int target_pstate; + struct sample *sample; + int target_pstate, from; + u64 time; + bool sample_taken; update_turbo_state(); @@ -1969,12 +1972,32 @@ static int intel_cpufreq_target(struct cpufreq_policy *policy, break; } target_pstate = intel_pstate_prepare_request(cpu, target_pstate); + + from = cpu->pstate.current_pstate; + time = ktime_get(); + sample_taken = intel_pstate_sample(cpu, time); + if (target_pstate != cpu->pstate.current_pstate) { cpu->pstate.current_pstate = target_pstate; wrmsrl_on_cpu(policy->cpu, MSR_IA32_PERF_CTL, pstate_funcs.get_val(cpu, target_pstate)); } freqs.new = target_pstate * cpu->pstate.scaling; + + if (sample_taken) { + intel_pstate_calc_avg_perf(cpu); + sample = &cpu->sample; + trace_pstate_sample(0, + 0, + from, + cpu->pstate.current_pstate, + sample->mperf, + sample->aperf, + sample->tsc, + get_avg_frequency(cpu), + fp_toint(cpu->iowait_boost * 100)); + } + cpufreq_freq_transition_end(policy, &freqs, false); return 0; @@ -1984,13 +2007,36 @@ static unsigned int intel_cpufreq_fast_switch(struct cpufreq_policy *policy, unsigned int target_freq) { struct cpudata *cpu = all_cpu_data[policy->cpu]; - int target_pstate; + struct sample *sample; + int target_pstate, from; + u64 time; + bool sample_taken; update_turbo_state(); target_pstate = DIV_ROUND_UP(target_freq, cpu->pstate.scaling); target_pstate = intel_pstate_prepare_request(cpu, target_pstate); + + from = cpu->pstate.current_pstate; + time = ktime_get(); + sample_taken = intel_pstate_sample(cpu, time); + intel_pstate_update_pstate(cpu, target_pstate); + + if (sample_taken) { + intel_pstate_calc_avg_perf(cpu); + sample = &cpu->sample; + trace_pstate_sample(100, + 0, + from, + cpu->pstate.current_pstate, + sample->mperf, + sample->aperf, + sample->tsc, + get_avg_frequency(cpu), + fp_toint(cpu->iowait_boost * 100)); + } + return target_pstate * cpu->pstate.scaling; } -- 2.7.4
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