Linux: add GPU meter and process column

Based on the DRM client usage stats[1] add statistics for GPU time spend
and percentage utilization.

[1]: https://www.kernel.org/doc/html/latest/gpu/drm-usage-stats.html

1 files changed, 179 insertions, 0 deletions

diff --git a/linux/GPUMeter.c b/linux/GPUMeter.c
new file mode 100644
index 00000000..fbd32ea8
--- /dev/null
+++ b/linux/GPUMeter.c
@@ -0,0 +1,179 @@
+/*
+htop - GPUMeter.c
+(C) 2023 htop dev team
+Released under the GNU GPLv2+, see the COPYING file
+in the source distribution for its full text.
+*/
+
+#include "config.h" // IWYU pragma: keep
+
+#include "linux/GPUMeter.h"
+
+#include "CRT.h"
+#include "RichString.h"
+#include "linux/LinuxMachine.h"
+
+
+static size_t activeMeters;
+
+bool GPUMeter_active(void) {
+   return activeMeters > 0;
+}
+
+struct EngineData {
+   const char* key;  /* owned by LinuxMachine */
+   unsigned long long int timeDiff;
+};
+
+static struct EngineData GPUMeter_engineData[4];
+static unsigned long long int prevResidueTime, curResidueTime;
+static double totalUsage;
+static unsigned long long int totalGPUTimeDiff;
+
+static const int GPUMeter_attributes[] = {
+   GPU_ENGINE_1,
+   GPU_ENGINE_2,
+   GPU_ENGINE_3,
+   GPU_ENGINE_4,
+   GPU_RESIDUE,
+};
+
+static int humanTimeUnit(char* buffer, size_t size, unsigned long long int value) {
+
+   if (value < 1000)
+      return xSnprintf(buffer, size, "%3lluns", value);
+
+   if (value < 10000)
+      return xSnprintf(buffer, size, "%1llu.%1lluus", value / 1000, (value % 1000) / 100);
+
+   value /= 1000;
+
+   if (value < 1000)
+      return xSnprintf(buffer, size, "%3lluus", value);
+
+   if (value < 10000)
+      return xSnprintf(buffer, size, "%1llu.%1llums", value / 1000, (value % 1000) / 100);
+
+   value /= 1000;
+
+   if (value < 1000)
+      return xSnprintf(buffer, size, "%3llums", value);
+
+   if (value < 10000)
+      return xSnprintf(buffer, size, "%1llu.%1llus", value / 1000, (value % 1000) / 100);
+
+   value /= 1000;
+
+   if (value < 600)
+      return xSnprintf(buffer, size, "%3llus", value);
+
+   value /= 60;
+
+   if (value < 600)
+      return xSnprintf(buffer, size, "%3llum", value);
+
+   value /= 60;
+
+   if (value < 96)
+      return xSnprintf(buffer, size, "%3lluh", value);
+
+   value /= 24;
+
+   return xSnprintf(buffer, size, "%3llud", value);
+}
+
+static void GPUMeter_updateValues(Meter* this) {
+   const Machine* host = this->host;
+   const LinuxMachine* lhost = (const LinuxMachine*) host;
+   const GPUEngineData* gpuEngineData;
+   char* buffer = this->txtBuffer;
+   size_t size = sizeof(this->txtBuffer);
+   int written;
+   unsigned int i;
+   uint64_t monotonictimeDelta;
+
+   assert(ARRAYSIZE(GPUMeter_engineData) + 1 == ARRAYSIZE(GPUMeter_attributes));
+
+   totalGPUTimeDiff = saturatingSub(lhost->curGpuTime, lhost->prevGpuTime);
+   monotonictimeDelta = host->monotonicMs - host->prevMonotonicMs;
+
+   prevResidueTime = curResidueTime;
+   curResidueTime = lhost->curGpuTime;
+
+   for (gpuEngineData = lhost->gpuEngineData, i = 0; gpuEngineData && i < ARRAYSIZE(GPUMeter_engineData); gpuEngineData = gpuEngineData->next, i++) {
+      GPUMeter_engineData[i].key      = gpuEngineData->key;
+      GPUMeter_engineData[i].timeDiff = saturatingSub(gpuEngineData->curTime, gpuEngineData->prevTime);
+
+      curResidueTime = saturatingSub(curResidueTime, gpuEngineData->curTime);
+
+      this->values[i] = 100.0 * GPUMeter_engineData[i].timeDiff / (1000 * 1000) / monotonictimeDelta;
+   }
+
+   this->values[ARRAYSIZE(GPUMeter_engineData)] = 100.0 * saturatingSub(curResidueTime, prevResidueTime) / (1000 * 1000) / monotonictimeDelta;
+
+   totalUsage = 100.0 * totalGPUTimeDiff / (1000 * 1000) / monotonictimeDelta;
+   written = snprintf(buffer, size, "%.1f", totalUsage);
+   METER_BUFFER_CHECK(buffer, size, written);
+
+   METER_BUFFER_APPEND_CHR(buffer, size, '%');
+}
+
+static void GPUMeter_display(const Object* cast, RichString* out) {
+   char buffer[50];
+   int written;
+   const Meter* this = (const Meter*)cast;
+   unsigned int i;
+
+   RichString_writeAscii(out, CRT_colors[METER_TEXT], ":");
+   written = xSnprintf(buffer, sizeof(buffer), "%4.1f", totalUsage);
+   RichString_appendnAscii(out, CRT_colors[METER_VALUE], buffer, written);
+   RichString_appendnAscii(out, CRT_colors[METER_TEXT], "%(", 2);
+   written = humanTimeUnit(buffer, sizeof(buffer), totalGPUTimeDiff);
+   RichString_appendnAscii(out, CRT_colors[METER_VALUE], buffer, written);
+   RichString_appendnAscii(out, CRT_colors[METER_TEXT], ")", 1);
+
+   for (i = 0; i < ARRAYSIZE(GPUMeter_engineData); i++) {
+      if (!GPUMeter_engineData[i].key)
+         break;
+
+      RichString_appendnAscii(out, CRT_colors[METER_TEXT], " ", 1);
+      RichString_appendAscii(out, CRT_colors[METER_TEXT], GPUMeter_engineData[i].key);
+      RichString_appendnAscii(out, CRT_colors[METER_TEXT], ":", 1);
+      if (isNonnegative(this->values[i]))
+         written = xSnprintf(buffer, sizeof(buffer), "%4.1f", this->values[i]);
+      else
+         written = xSnprintf(buffer, sizeof(buffer), " N/A");
+      RichString_appendnAscii(out, CRT_colors[METER_VALUE], buffer, written);
+      RichString_appendnAscii(out, CRT_colors[METER_TEXT], "%(", 2);
+      written = humanTimeUnit(buffer, sizeof(buffer), GPUMeter_engineData[i].timeDiff);
+      RichString_appendnAscii(out, CRT_colors[METER_VALUE], buffer, written);
+      RichString_appendnAscii(out, CRT_colors[METER_TEXT], ")", 1);
+   }
+}
+
+static void GPUMeter_init(Meter* this ATTR_UNUSED) {
+   activeMeters++;
+}
+
+static void GPUMeter_done(Meter* this ATTR_UNUSED) {
+   assert(activeMeters > 0);
+   activeMeters--;
+}
+
+const MeterClass GPUMeter_class = {
+   .super = {
+      .extends = Class(Meter),
+      .delete = Meter_delete,
+      .display = GPUMeter_display,
+   },
+   .init = GPUMeter_init,
+   .done = GPUMeter_done,
+   .updateValues = GPUMeter_updateValues,
+   .defaultMode = BAR_METERMODE,
+   .maxItems = ARRAYSIZE(GPUMeter_engineData) + 1,
+   .total = 100.0,
+   .attributes = GPUMeter_attributes,
+   .name = "GPU",
+   .uiName = "GPU usage",
+   .caption = "GPU"
+};