experiments/drive.cpp - openbmc/phosphor-pid-control - Gitiles

 /**
  * Copyright 2017 Google Inc.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *     http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 #include <iostream>
 #include <memory>
 #include <tuple>

 #include "drive.hpp"

 #include "interfaces.hpp"
 #include "sensors/pluggable.hpp"
 #include "sysfs/sysfswrite.hpp"
 #include "sysfs/sysfsread.hpp"

 using tstamp = std::chrono::high_resolution_clock::time_point;

 #define DRIVE_TIME 1
 #define DRIVE_GOAL 2
 #define DRIVE DRIVE_TIME
 #define MAX_PWM 255

 static std::unique_ptr<Sensor> Create(
     std::string readpath,
     std::string writepath)
 {
     return std::make_unique<PluggableSensor>(
                readpath,
                0, /* default the timeout to disabled */
                std::make_unique<SysFsRead>(readpath),
                std::make_unique<SysFsWrite>(writepath, 0, MAX_PWM));
 }

 int64_t getAverage(std::tuple<tstamp, int64_t, int64_t>& values)
 {
     return (std::get<1>(values) + std::get<2>(values)) / 2;
 }

 bool valueClose(int64_t value, int64_t goal)
 {
 #if 0
     int64_t delta = 100; /* within 100 */
     if (value < (goal + delta) &&
         value > (goal - delta))
     {
         return true;
     }
 #endif

     /* let's make sure it's below goal. */
     if (value < goal)
     {
         return true;
     }

     return false;
 }

 static void driveGoal(
     int64_t& seriesCnt,
     int64_t setPwm,
     int64_t goal,
     std::vector<std::tuple<tstamp, int64_t, int64_t>>& series,
     std::vector<std::unique_ptr<Sensor>>& fanSensors)
 {
     bool reading = true;

     auto& fan0 = fanSensors.at(0);
     auto& fan1 = fanSensors.at(1);

     fan0->write(setPwm);
     fan1->write(setPwm);

     while (reading)
     {
         bool check = false;
         ReadReturn r0 = fan0->read();
         ReadReturn r1 = fan1->read();
         int64_t n0 = static_cast<int64_t>(r0.value);
         int64_t n1 = static_cast<int64_t>(r1.value);

         tstamp t1 = std::chrono::high_resolution_clock::now();

         series.push_back(std::make_tuple(t1, n0, n1));
         seriesCnt += 1;

         int64_t avgn = (n0 + n1) / 2;
         /* check last three values against goal if this is close */
         check = valueClose(avgn, goal);

         /* We know the last entry is within range. */
         if (check && seriesCnt > 3)
         {
             /* n-2 values */
             std::tuple<tstamp, int64_t, int64_t> nm2 = series.at(seriesCnt - 3);
             /* n-1 values */
             std::tuple<tstamp, int64_t, int64_t> nm1 = series.at(seriesCnt - 2);

             int64_t avgnm2 = getAverage(nm2);
             int64_t avgnm1 = getAverage(nm1);

             int64_t together = (avgnm2 + avgnm1) / 2;

             reading = !valueClose(together, goal);

             if (!reading)
             {
                 std::cerr << "finished reaching goal\n";
             }
         }

         /* Early abort for testing. */
         if (seriesCnt > 150000)
         {
             std::cerr << "aborting after 150000 reads.\n";
             reading = false;
         }
     }

     return;
 }

 static void driveTime(
     int64_t& seriesCnt,
     int64_t setPwm,
     int64_t goal,
     std::vector<std::tuple<tstamp, int64_t, int64_t>>& series,
     std::vector<std::unique_ptr<Sensor>>& fanSensors)
 {
     using namespace std::literals::chrono_literals;

     bool reading = true;

     auto& fan0 = fanSensors.at(0);
     auto& fan1 = fanSensors.at(1);

     auto& s0 = series.at(0);
     tstamp t0 = std::get<0>(s0);

     fan0->write(setPwm);
     fan1->write(setPwm);

     while (reading)
     {
         ReadReturn r0 = fan0->read();
         ReadReturn r1 = fan1->read();
         int64_t n0 = static_cast<int64_t>(r0.value);
         int64_t n1 = static_cast<int64_t>(r1.value);
         tstamp t1 = std::chrono::high_resolution_clock::now();

         series.push_back(std::make_tuple(t1, n0, n1));

         auto duration = std::chrono::duration_cast<std::chrono::microseconds>
                         (t1 - t0).count();
         if (duration >= (20000000us).count())
         {
             reading = false;
         }
     }

     return;
 }

 int driveMain(void)
 {
     /* Time series of the data, the timestamp after both are read and the values. */
     std::vector<std::tuple<tstamp, int64_t, int64_t>> series;
     int64_t seriesCnt = 0; /* in case vector count isn't constant time */
     int drive = DRIVE;

     /*
      * The fan map:
      *  --> 0 | 4
      *  --> 1 | 5
      *  --> 2 | 6
      *  --> 3 | 7
      */
     std::vector<std::string> fans =
     {
         "/sys/class/hwmon/hwmon0/fan0_input",
         "/sys/class/hwmon/hwmon0/fan4_input"
     };

     std::vector<std::string> pwms =
     {
         "/sys/class/hwmon/hwmon0/pwm0",
         "/sys/class/hwmon/hwmon0/pwm4"
     };

     std::vector<std::unique_ptr<Sensor>> fanSensors;

     auto fan0 = Create(fans[0], pwms[0]);
     auto fan1 = Create(fans[1], pwms[1]);

     ReadReturn r0 = fan0->read();
     ReadReturn r1 = fan1->read();
     int64_t pwm0_value = static_cast<int64_t>(r0.value);
     int64_t pwm1_value = static_cast<int64_t>(r1.value);

     if (MAX_PWM != pwm0_value || MAX_PWM != pwm1_value)
     {
         std::cerr << "bad PWM starting point.\n";
         return -EINVAL;
     }

     r0 = fan0->read();
     r1 = fan1->read();
     int64_t fan0_start = r0.value;
     int64_t fan1_start = r1.value;
     tstamp t1 = std::chrono::high_resolution_clock::now();

     /*
      * I've done experiments, and seen 9080,10243 as a starting point
      * which leads to a 50% goal of 4830.5, which is higher than the
      * average that they reach, 4668.  -- i guess i could try to figure out
      * a good increase from one to the other, but how fast they're going
      * actually influences how much they influence, so at slower speeds the
      * improvement is less.
      */

     series.push_back(std::make_tuple(t1, fan0_start, fan1_start));
     seriesCnt += 1;

     int64_t average = (fan0_start + fan1_start) / 2;
     int64_t goal = 0.5 * average;

     std::cerr << "goal: " << goal << "\n";

     // fan0 @ 128: 4691
     // fan4 @ 128: 4707

     fanSensors.push_back(std::move(fan0));
     fanSensors.push_back(std::move(fan1));

     if (DRIVE_TIME == drive)
     {
         driveTime(seriesCnt, 128, goal, series, fanSensors);
     }
     else if (DRIVE_GOAL == drive)
     {
         driveGoal(seriesCnt, 128, goal, series, fanSensors);
     }
     tstamp tp = t1;

     /* Output the values and the timepoints as a time series for review. */
     for (auto& t : series)
     {
         tstamp ts = std::get<0>(t);
         int64_t n0 = std::get<1>(t);
         int64_t n1 = std::get<2>(t);

         auto duration = std::chrono::duration_cast<std::chrono::microseconds>
                         (ts - tp).count();
         std::cout << duration << "us, " << n0 << ", " << n1 << "\n";

         tp = ts;
     }

     return 0;
 }
	/**
	* Copyright 2017 Google Inc.
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	#include <iostream>
	#include <memory>
	#include <tuple>

	#include "drive.hpp"

	#include "interfaces.hpp"
	#include "sensors/pluggable.hpp"
	#include "sysfs/sysfswrite.hpp"
	#include "sysfs/sysfsread.hpp"

	using tstamp = std::chrono::high_resolution_clock::time_point;

	#define DRIVE_TIME 1
	#define DRIVE_GOAL 2
	#define DRIVE DRIVE_TIME
	#define MAX_PWM 255

	static std::unique_ptr<Sensor> Create(
	std::string readpath,
	std::string writepath)
	{
	return std::make_unique<PluggableSensor>(
	readpath,
	0, /* default the timeout to disabled */
	std::make_unique<SysFsRead>(readpath),
	std::make_unique<SysFsWrite>(writepath, 0, MAX_PWM));
	}

	int64_t getAverage(std::tuple<tstamp, int64_t, int64_t>& values)
	{
	return (std::get<1>(values) + std::get<2>(values)) / 2;
	}

	bool valueClose(int64_t value, int64_t goal)
	{
	#if 0
	int64_t delta = 100; /* within 100 */
	if (value < (goal + delta) &&
	value > (goal - delta))
	{
	return true;
	}
	#endif

	/* let's make sure it's below goal. */
	if (value < goal)
	{
	return true;
	}

	return false;
	}

	static void driveGoal(
	int64_t& seriesCnt,
	int64_t setPwm,
	int64_t goal,
	std::vector<std::tuple<tstamp, int64_t, int64_t>>& series,
	std::vector<std::unique_ptr<Sensor>>& fanSensors)
	{
	bool reading = true;

	auto& fan0 = fanSensors.at(0);
	auto& fan1 = fanSensors.at(1);

	fan0->write(setPwm);
	fan1->write(setPwm);

	while (reading)
	{
	bool check = false;
	ReadReturn r0 = fan0->read();
	ReadReturn r1 = fan1->read();
	int64_t n0 = static_cast<int64_t>(r0.value);
	int64_t n1 = static_cast<int64_t>(r1.value);

	tstamp t1 = std::chrono::high_resolution_clock::now();

	series.push_back(std::make_tuple(t1, n0, n1));
	seriesCnt += 1;

	int64_t avgn = (n0 + n1) / 2;
	/* check last three values against goal if this is close */
	check = valueClose(avgn, goal);

	/* We know the last entry is within range. */
	if (check && seriesCnt > 3)
	{
	/* n-2 values */
	std::tuple<tstamp, int64_t, int64_t> nm2 = series.at(seriesCnt - 3);
	/* n-1 values */
	std::tuple<tstamp, int64_t, int64_t> nm1 = series.at(seriesCnt - 2);

	int64_t avgnm2 = getAverage(nm2);
	int64_t avgnm1 = getAverage(nm1);

	int64_t together = (avgnm2 + avgnm1) / 2;

	reading = !valueClose(together, goal);

	if (!reading)
	{
	std::cerr << "finished reaching goal\n";
	}
	}

	/* Early abort for testing. */
	if (seriesCnt > 150000)
	{
	std::cerr << "aborting after 150000 reads.\n";
	reading = false;
	}
	}

	return;
	}

	static void driveTime(
	int64_t& seriesCnt,
	int64_t setPwm,
	int64_t goal,
	std::vector<std::tuple<tstamp, int64_t, int64_t>>& series,
	std::vector<std::unique_ptr<Sensor>>& fanSensors)
	{
	using namespace std::literals::chrono_literals;

	bool reading = true;

	auto& fan0 = fanSensors.at(0);
	auto& fan1 = fanSensors.at(1);

	auto& s0 = series.at(0);
	tstamp t0 = std::get<0>(s0);

	fan0->write(setPwm);
	fan1->write(setPwm);

	while (reading)
	{
	ReadReturn r0 = fan0->read();
	ReadReturn r1 = fan1->read();
	int64_t n0 = static_cast<int64_t>(r0.value);
	int64_t n1 = static_cast<int64_t>(r1.value);
	tstamp t1 = std::chrono::high_resolution_clock::now();

	series.push_back(std::make_tuple(t1, n0, n1));

	auto duration = std::chrono::duration_cast<std::chrono::microseconds>
	(t1 - t0).count();
	if (duration >= (20000000us).count())
	{
	reading = false;
	}
	}

	return;
	}

	int driveMain(void)
	{
	/* Time series of the data, the timestamp after both are read and the values. */
	std::vector<std::tuple<tstamp, int64_t, int64_t>> series;
	int64_t seriesCnt = 0; /* in case vector count isn't constant time */
	int drive = DRIVE;

	/*
	* The fan map:
	* --> 0 \| 4
	* --> 1 \| 5
	* --> 2 \| 6
	* --> 3 \| 7
	*/
	std::vector<std::string> fans =
	{
	"/sys/class/hwmon/hwmon0/fan0_input",
	"/sys/class/hwmon/hwmon0/fan4_input"
	};

	std::vector<std::string> pwms =
	{
	"/sys/class/hwmon/hwmon0/pwm0",
	"/sys/class/hwmon/hwmon0/pwm4"
	};

	std::vector<std::unique_ptr<Sensor>> fanSensors;

	auto fan0 = Create(fans[0], pwms[0]);
	auto fan1 = Create(fans[1], pwms[1]);

	ReadReturn r0 = fan0->read();
	ReadReturn r1 = fan1->read();
	int64_t pwm0_value = static_cast<int64_t>(r0.value);
	int64_t pwm1_value = static_cast<int64_t>(r1.value);

	if (MAX_PWM != pwm0_value \|\| MAX_PWM != pwm1_value)
	{
	std::cerr << "bad PWM starting point.\n";
	return -EINVAL;
	}

	r0 = fan0->read();
	r1 = fan1->read();
	int64_t fan0_start = r0.value;
	int64_t fan1_start = r1.value;
	tstamp t1 = std::chrono::high_resolution_clock::now();

	/*
	* I've done experiments, and seen 9080,10243 as a starting point
	* which leads to a 50% goal of 4830.5, which is higher than the
	* average that they reach, 4668. -- i guess i could try to figure out
	* a good increase from one to the other, but how fast they're going
	* actually influences how much they influence, so at slower speeds the
	* improvement is less.
	*/

	series.push_back(std::make_tuple(t1, fan0_start, fan1_start));
	seriesCnt += 1;

	int64_t average = (fan0_start + fan1_start) / 2;
	int64_t goal = 0.5 * average;

	std::cerr << "goal: " << goal << "\n";

	// fan0 @ 128: 4691
	// fan4 @ 128: 4707

	fanSensors.push_back(std::move(fan0));
	fanSensors.push_back(std::move(fan1));

	if (DRIVE_TIME == drive)
	{
	driveTime(seriesCnt, 128, goal, series, fanSensors);
	}
	else if (DRIVE_GOAL == drive)
	{
	driveGoal(seriesCnt, 128, goal, series, fanSensors);
	}
	tstamp tp = t1;

	/* Output the values and the timepoints as a time series for review. */
	for (auto& t : series)
	{
	tstamp ts = std::get<0>(t);
	int64_t n0 = std::get<1>(t);
	int64_t n1 = std::get<2>(t);

	auto duration = std::chrono::duration_cast<std::chrono::microseconds>
	(ts - tp).count();
	std::cout << duration << "us, " << n0 << ", " << n1 << "\n";

	tp = ts;
	}

	return 0;
	}