mangoapp: amdgpu: pause the polling thread when it's not needed

src/amdgpu.cpp

@@ -14,6 +14,9 @@
 std::string metrics_path = "";
 struct amdgpu_common_metrics amdgpu_common_metrics;
 std::mutex amdgpu_common_metrics_m;
+std::mutex amdgpu_m;
+std::condition_variable amdgpu_c;
+bool amdgpu_run_thread = false;
 
 bool amdgpu_verify_metrics(const std::string& path)
 {
@@ -233,6 +236,9 @@ void amdgpu_metrics_polling_thread() {
 	memset(metrics_buffer, 0, sizeof(metrics_buffer));
 
 	while (1) {
+		std::unique_lock<std::mutex> lock(amdgpu_m);
+		amdgpu_c.wait(lock, []{return amdgpu_run_thread;});
+		lock.unlock();
 #ifndef TEST_ONLY
 		if (HUDElements.params->no_display && !logger->is_active())
 			usleep(100000);

src/amdgpu.h

@@ -6,6 +6,8 @@
 #include <unistd.h>
 #include <string>
 #include "overlay_params.h"
+#include <mutex>
+#include <condition_variable>
 // #include <vector>
 
 #define METRICS_UPDATE_PERIOD_MS 500
@@ -188,6 +190,8 @@ struct amdgpu_common_metrics {
 bool amdgpu_verify_metrics(const std::string& path);
 void amdgpu_get_metrics();
 extern std::string metrics_path;
+extern std::condition_variable amdgpu_c;
+extern bool amdgpu_run_thread;
 void amdgpu_get_instant_metrics(struct amdgpu_common_metrics *metrics);
 void amdgpu_metrics_polling_thread();
 void amdgpu_get_samples_and_copy(struct amdgpu_common_metrics metrics_buffer[METRICS_SAMPLE_COUNT], bool &gpu_load_needs_dividing);

src/app/main.cpp

@@ -18,6 +18,7 @@
 #include "mangoapp_proto.h"
 #include <GL/glew.h>
 #include <GLFW/glfw3.h>
+#include "amdgpu.h"
 
 #define GLFW_EXPOSE_NATIVE_X11
 #include <GLFW/glfw3native.h>
@@ -310,6 +311,10 @@ int main(int, char**)
                 XChangeProperty(x11_display, x11_window, overlay_atom, XA_CARDINAL, 32, PropModeReplace, (unsigned char *)&value, 1);
                 XSync(x11_display, 0);
                 mangoapp_paused = false;
+                {
+                    amdgpu_run_thread = true;
+                    amdgpu_c.notify_one();
+                }
             }
             {
                 std::unique_lock<std::mutex> lk(mangoapp_m);
@@ -349,6 +354,10 @@ int main(int, char**)
             XChangeProperty(x11_display, x11_window, overlay_atom, XA_CARDINAL, 32, PropModeReplace, (unsigned char *)&value, 1);
             XSync(x11_display, 0);
             mangoapp_paused = true;
+            {
+                amdgpu_run_thread = false;
+                amdgpu_c.notify_one();
+            }
             std::unique_lock<std::mutex> lk(mangoapp_m);
             mangoapp_cv.wait(lk, []{return !params.no_display;});
         }