tools/gator/daemon/CPUFreqDriver.cpp

   1 /**
   2  * Copyright (C) ARM Limited 2013-2014. All rights reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License version 2 as
   6  * published by the Free Software Foundation.
   7  */
   8
   9 #include "CPUFreqDriver.h"
  10
  11 #include "Buffer.h"
  12 #include "DriverSource.h"
  13 #include "Logging.h"
  14 #include "SessionData.h"
  15
  16 CPUFreqDriver::CPUFreqDriver() : mPrev() {
  17 }
  18
  19 CPUFreqDriver::~CPUFreqDriver() {
  20 }
  21
  22 void CPUFreqDriver::readEvents(mxml_node_t *const) {
  23         // Only for use with perf
  24         if (!gSessionData->perf.isSetup()) {
  25                 return;
  26         }
  27
  28         setCounters(new DriverCounter(getCounters(), strdup("Linux_power_cpu_freq")));
  29 }
  30
  31 void CPUFreqDriver::read(Buffer *const buffer) {
  32         char buf[64];
  33         const DriverCounter *const counter = getCounters();
  34         if ((counter == NULL) || !counter->isEnabled()) {
  35                 return;
  36         }
  37
  38         const int key = getCounters()->getKey();
  39         bool resetCores = false;
  40         for (int i = 0; i < gSessionData->mCores; ++i) {
  41                 snprintf(buf, sizeof(buf), "/sys/devices/system/cpu/cpu%i/cpufreq/cpuinfo_cur_freq", i);
  42                 int64_t freq;
  43                 if (DriverSource::readInt64Driver(buf, &freq) != 0) {
  44                         freq = 0;
  45                 }
  46                 if (mPrev[i] != freq) {
  47                         mPrev[i] = freq;
  48                         // Change cores
  49                         buffer->event64(2, i);
  50                         resetCores = true;
  51                         buffer->event64(key, 1000*freq);
  52                 }
  53         }
  54         if (resetCores) {
  55                 // Revert cores, UserSpaceSource is all on core 0
  56                 buffer->event64(2, 0);
  57         }
  58 }