git.sesse.net Git - nageru/blob - gpu_timers.cpp

   1 #include "gpu_timers.h"
   2
   3 #include <epoxy/gl.h>
   4
   5 using namespace std;
   6
   7 bool enable_timing = false;
   8 bool detailed_timing = false;
   9 bool in_warmup = false;
  10
  11 pair<GLuint, GLuint> GPUTimers::begin_timer(const string &name, int level)
  12 {
  13         if (!enable_timing) {
  14                 return make_pair(0, 0);
  15         }
  16
  17         GLuint queries[2];
  18         glGenQueries(2, queries);
  19         glQueryCounter(queries[0], GL_TIMESTAMP);
  20
  21         Timer timer;
  22         timer.name = name;
  23         timer.level = level;
  24         timer.query.first = queries[0];
  25         timer.query.second = queries[1];
  26         timers.push_back(timer);
  27         return timer.query;
  28 }
  29
  30 GLint64 find_elapsed(pair<GLuint, GLuint> queries)
  31 {
  32         // NOTE: This makes the CPU wait for the GPU.
  33         GLuint64 time_start, time_end;
  34         glGetQueryObjectui64v(queries.first, GL_QUERY_RESULT, &time_start);
  35         glGetQueryObjectui64v(queries.second, GL_QUERY_RESULT, &time_end);
  36         return time_end - time_start;
  37 }
  38
  39 void GPUTimers::print()
  40 {
  41         for (size_t i = 0; i < timers.size(); ++i) {
  42                 if (timers[i].level >= 4 && !detailed_timing) {
  43                         // In practice, only affects the SOR sub-timers.
  44                         continue;
  45                 }
  46
  47                 GLint64 time_elapsed = find_elapsed(timers[i].query);
  48                 for (int j = 0; j < timers[i].level * 2; ++j) {
  49                         fprintf(stderr, " ");
  50                 }
  51
  52                 if (detailed_timing) {
  53                         // Look for any immediate subtimers, and see if they sum to the large one.
  54                         size_t num_subtimers = 0;
  55                         GLint64 sum_subtimers = 0;
  56                         for (size_t j = i + 1; j < timers.size() && timers[j].level > timers[i].level; ++j) {
  57                                 if (timers[j].level != timers[i].level + 1)
  58                                         continue;
  59                                 ++num_subtimers;
  60                                 sum_subtimers += find_elapsed(timers[j].query);
  61                         }
  62
  63                         if (num_subtimers > 0 && (time_elapsed - sum_subtimers) / 1e6 >= 0.01) {
  64                                 fprintf(stderr, "%-30s %4.3f ms [%4.3f ms unaccounted for]\n", timers[i].name.c_str(), time_elapsed / 1e6, (time_elapsed - sum_subtimers) / 1e6);
  65                         } else {
  66                                 fprintf(stderr, "%-30s %4.3f ms\n", timers[i].name.c_str(), time_elapsed / 1e6);
  67                         }
  68                 } else {
  69                         fprintf(stderr, "%-30s %4.1f ms\n", timers[i].name.c_str(), time_elapsed / 1e6);
  70                 }
  71         }
  72 }