CPU: Only use active CPU count for generic CPU progress.

Some systems disable CPU cores. In the CPU tab this is fine,
but for an accurate representation of CPU load we need to check
for the number of active CPUs. E.g. OpenBSD disables HT on amd64
thus a 2-core system will only use 1 core.

src/system.c

@@ -206,6 +206,26 @@ cpu_count(void)
    return cores;
 }
 
+int
+system_cpu_online_count_get(void)
+{
+#if defined(__linux__)
+   return cpu_count();
+#endif
+   static int cores = 0;
+
+   if (cores != 0) return cores;
+
+   size_t len;
+   int mib[2] = { CTL_HW, HW_NCPUONLINE };
+
+   len = sizeof(cores);
+   if (sysctl(mib, 2, &cores, &len, NULL, 0) < 0)
+     return cpu_count();
+
+   return cores;
+}
+
 static void
 _cpu_state_get(cpu_core_t **cores, int ncpu)
 {

src/system.h

@@ -74,4 +74,7 @@ int
 void
  system_power_state_get(power_t *power);
 
+int
+ system_cpu_online_count_get();
+
 #endif

src/ui.c

@@ -434,7 +434,7 @@ _system_stats_feedback_cb(void *data, Ecore_Thread *thread, void *msg)
         free(results->cores[i]);
      }
 
-   cpu_usage = cpu_usage / results->cpu_count;
+   cpu_usage = cpu_usage / system_cpu_online_count_get();
 
    _progressbar_value_force_set(ui->progress_cpu, (double)cpu_usage / 100);