tools/gator/daemon/KMod.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 "KMod.h"
  10
  11 #include <sys/types.h>
  12 #include <dirent.h>
  13 #include <unistd.h>
  14
  15 #include "ConfigurationXML.h"
  16 #include "Counter.h"
  17 #include "DriverSource.h"
  18 #include "Logging.h"
  19
  20 // Claim all the counters in /dev/gator/events
  21 bool KMod::claimCounter(const Counter &counter) const {
  22         char text[128];
  23         snprintf(text, sizeof(text), "/dev/gator/events/%s", counter.getType());
  24         return access(text, F_OK) == 0;
  25 }
  26
  27 void KMod::resetCounters() {
  28         char base[128];
  29         char text[128];
  30
  31         // Initialize all perf counters in the driver, i.e. set enabled to zero
  32         struct dirent *ent;
  33         DIR* dir = opendir("/dev/gator/events");
  34         if (dir) {
  35                 while ((ent = readdir(dir)) != NULL) {
  36                         // skip hidden files, current dir, and parent dir
  37                         if (ent->d_name[0] == '.')
  38                                 continue;
  39                         snprintf(base, sizeof(base), "/dev/gator/events/%s", ent->d_name);
  40                         snprintf(text, sizeof(text), "%s/enabled", base);
  41                         DriverSource::writeDriver(text, 0);
  42                         snprintf(text, sizeof(text), "%s/count", base);
  43                         DriverSource::writeDriver(text, 0);
  44                 }
  45                 closedir(dir);
  46         }
  47 }
  48
  49 void KMod::setupCounter(Counter &counter) {
  50         char base[128];
  51         char text[128];
  52         snprintf(base, sizeof(base), "/dev/gator/events/%s", counter.getType());
  53
  54         snprintf(text, sizeof(text), "%s/enabled", base);
  55         int enabled = true;
  56         if (DriverSource::writeReadDriver(text, &enabled) || !enabled) {
  57                 counter.setEnabled(false);
  58                 return;
  59         }
  60
  61         int value = 0;
  62         snprintf(text, sizeof(text), "%s/key", base);
  63         DriverSource::readIntDriver(text, &value);
  64         counter.setKey(value);
  65
  66         snprintf(text, sizeof(text), "%s/cores", base);
  67         if (DriverSource::readIntDriver(text, &value) == 0) {
  68                 counter.setCores(value);
  69         }
  70
  71         snprintf(text, sizeof(text), "%s/event", base);
  72         DriverSource::writeDriver(text, counter.getEvent());
  73         snprintf(text, sizeof(text), "%s/count", base);
  74         if (access(text, F_OK) == 0) {
  75                 int count = counter.getCount();
  76                 if (DriverSource::writeReadDriver(text, &count) && counter.getCount() > 0) {
  77                         logg->logError(__FILE__, __LINE__, "Cannot enable EBS for %s:%i with a count of %d\n", counter.getType(), counter.getEvent(), counter.getCount());
  78                         handleException();
  79                 }
  80                 counter.setCount(count);
  81         } else if (counter.getCount() > 0) {
  82                 ConfigurationXML::remove();
  83                 logg->logError(__FILE__, __LINE__, "Event Based Sampling is only supported with kernel versions 3.0.0 and higher with CONFIG_PERF_EVENTS=y, and CONFIG_HW_PERF_EVENTS=y. The invalid configuration.xml has been removed.\n");
  84                 handleException();
  85         }
  86 }
  87
  88 int KMod::writeCounters(mxml_node_t *root) const {
  89         struct dirent *ent;
  90         mxml_node_t *counter;
  91
  92         // counters.xml is simply a file listing of /dev/gator/events
  93         DIR* dir = opendir("/dev/gator/events");
  94         if (dir == NULL) {
  95                 return 0;
  96         }
  97
  98         int count = 0;
  99         while ((ent = readdir(dir)) != NULL) {
 100                 // skip hidden files, current dir, and parent dir
 101                 if (ent->d_name[0] == '.')
 102                         continue;
 103                 counter = mxmlNewElement(root, "counter");
 104                 mxmlElementSetAttr(counter, "name", ent->d_name);
 105                 ++count;
 106         }
 107         closedir(dir);
 108
 109         return count;
 110 }