Add new display option to also show CPU frequency in CPU meters.

The option is only implemented on Linux. On other platforms, and on Linuxes
that do not expose the relevant sysfs file, the frequency will be 0.

The "CPU average" meter does not show a frequency, only
the individual per-CPU meters.

CPUMeter.c

@@ -28,7 +28,8 @@ typedef enum {
    CPU_METER_STEAL = 5,
    CPU_METER_GUEST = 6,
    CPU_METER_IOWAIT = 7,
-   CPU_METER_ITEMCOUNT = 8, // number of entries in this enum
+   CPU_METER_FREQUENCY = 8,
+   CPU_METER_ITEMCOUNT = 9, // number of entries in this enum
 } CPUMeterValues;
 
 }*/
@@ -63,8 +64,23 @@ static void CPUMeter_updateValues(Meter* this, char* buffer, int size) {
    }
    memset(this->values, 0, sizeof(double) * CPU_METER_ITEMCOUNT);
    double percent = Platform_setCPUValues(this, cpu);
+   if (cpu != 0 && this->pl->settings->showCPUFrequency) {
+      /* Initial frequency is in KHz. Divide it by 1024 till it's less than 1024, and emit unit accordingly */
+      double cpuFrequency = this->values[CPU_METER_FREQUENCY];
+      char unit = 'K';
+      if (cpuFrequency > 1024) {
+         cpuFrequency /= 1024;
+         unit = 'M';
+      }
+      if (cpuFrequency > 1024) {
+         cpuFrequency /= 1024;
+         unit = 'G';
+      }
+      xSnprintf(buffer, size, "%5.1f%% %.1f%cHz", percent, cpuFrequency, unit);
+   } else {
       xSnprintf(buffer, size, "%5.1f%%", percent);
    }
+}
 
 static void CPUMeter_display(Object* cast, RichString* out) {
    char buffer[50];

CPUMeter.h

@@ -20,7 +20,8 @@ typedef enum {
    CPU_METER_STEAL = 5,
    CPU_METER_GUEST = 6,
    CPU_METER_IOWAIT = 7,
-   CPU_METER_ITEMCOUNT = 8, // number of entries in this enum
+   CPU_METER_FREQUENCY = 8,
+   CPU_METER_ITEMCOUNT = 9, // number of entries in this enum
 } CPUMeterValues;
 
 

DisplayOptionsPanel.c

@@ -97,5 +97,6 @@ DisplayOptionsPanel* DisplayOptionsPanel_new(Settings* settings, ScreenManager*
    Panel_add(super, (Object*) CheckItem_newByRef(xStrdup("Count CPUs from 0 instead of 1"), &(settings->countCPUsFromZero)));
    Panel_add(super, (Object*) CheckItem_newByRef(xStrdup("Update process names on every refresh"), &(settings->updateProcessNames)));
    Panel_add(super, (Object*) CheckItem_newByRef(xStrdup("Add guest time in CPU meter percentage"), &(settings->accountGuestInCPUMeter)));
+   Panel_add(super, (Object*) CheckItem_newByRef(xStrdup("Also show CPU frequency"), &(settings->showCPUFrequency)));
    return this;
 }

Settings.c

@@ -45,6 +45,7 @@ typedef struct Settings_ {
 
    bool countCPUsFromZero;
    bool detailedCPUTime;
+   bool showCPUFrequency;
    bool treeView;
    bool showProgramPath;
    bool hideThreads;
@@ -223,6 +224,8 @@ static bool Settings_read(Settings* this, const char* fileName) {
          this->detailedCPUTime = atoi(option[1]);
       } else if (String_eq(option[0], "cpu_count_from_zero")) {
          this->countCPUsFromZero = atoi(option[1]);
+      } else if (String_eq(option[0], "show_cpu_frequency")) {
+         this->showCPUFrequency = atoi(option[1]);
       } else if (String_eq(option[0], "update_process_names")) {
          this->updateProcessNames = atoi(option[1]);
       } else if (String_eq(option[0], "account_guest_in_cpu_meter")) {
@@ -312,6 +315,7 @@ bool Settings_write(Settings* this) {
    fprintf(fd, "header_margin=%d\n", (int) this->headerMargin);
    fprintf(fd, "detailed_cpu_time=%d\n", (int) this->detailedCPUTime);
    fprintf(fd, "cpu_count_from_zero=%d\n", (int) this->countCPUsFromZero);
+   fprintf(fd, "show_cpu_frequency=%d\n", (int) this->showCPUFrequency);
    fprintf(fd, "update_process_names=%d\n", (int) this->updateProcessNames);
    fprintf(fd, "account_guest_in_cpu_meter=%d\n", (int) this->accountGuestInCPUMeter);
    fprintf(fd, "color_scheme=%d\n", (int) this->colorScheme);
@@ -340,6 +344,7 @@ Settings* Settings_new(int cpuCount) {
    this->highlightMegabytes = false;
    this->detailedCPUTime = false;
    this->countCPUsFromZero = false;
+   this->showCPUFrequency = false;
    this->updateProcessNames = false;
    this->cpuCount = cpuCount;
    this->showProgramPath = true;

Settings.h

@@ -36,6 +36,7 @@ typedef struct Settings_ {
 
    bool countCPUsFromZero;
    bool detailedCPUTime;
+   bool showCPUFrequency;
    bool treeView;
    bool showProgramPath;
    bool hideThreads;

linux/Platform.c

@@ -192,6 +192,22 @@ double Platform_setCPUValues(Meter* this, int cpu) {
    }
    percent = CLAMP(percent, 0.0, 100.0);
    if (isnan(percent)) percent = 0.0;
+
+   v[CPU_METER_FREQUENCY] = 0;
+   if (this->pl->settings->showCPUFrequency) {
+      char filename[63+1];
+      xSnprintf(filename, 63, "/sys/devices/system/cpu/cpu%d/cpufreq/scaling_cur_freq", cpu - 1);
+      FILE* fd = fopen(filename, "r");
+      if (fd) {
+         unsigned int cpuFrequency;
+         int n = fscanf(fd, "%u", &cpuFrequency);
+         fclose(fd);
+         if (n > 0) {
+            v[CPU_METER_FREQUENCY] = cpuFrequency;
+         }
+      }
+   }
+
    return percent;
 }