Add GPUMeter code for Darwin

Co-authored-by: Matteo Nicoli <[email protected]>
Signed-off-by: Kang-Che Sung <[email protected]>

Makefile.am

@@ -367,6 +367,7 @@ darwin_platform_headers = \
 	zfs/ZfsCompressedArcMeter.h
 
 darwin_platform_sources = \
+	GPUMeter.c \
 	darwin/Platform.c \
 	darwin/PlatformHelpers.c \
 	darwin/DarwinMachine.c \

darwin/DarwinMachine.c

@@ -105,12 +105,19 @@ Machine* Machine_new(UsersTable* usersTable, uid_t userId) {
    openzfs_sysctl_init(&this->zfs);
    openzfs_sysctl_updateArcStats(&this->zfs);
 
+   this->GPUService = IOServiceGetMatchingService(kIOMainPortDefault, IOServiceMatching("IOGPU"));
+   if (!this->GPUService) {
+      CRT_debug("Cannot initialize IOGPU service");
+   }
+
    return super;
 }
 
 void Machine_delete(Machine* super) {
    DarwinMachine* this = (DarwinMachine*) super;
 
+   IOObjectRelease(this->GPUService);
+
    DarwinMachine_freeCPULoadInfo(&this->prev_load);
 
    Machine_done(super);

darwin/DarwinMachine.h

@@ -7,6 +7,7 @@ Released under the GNU GPLv2+, see the COPYING file
 in the source distribution for its full text.
 */
 
+#include <IOKit/IOKitLib.h>
 #include <mach/mach_host.h>
 #include <sys/sysctl.h>
 
@@ -26,6 +27,8 @@ typedef struct DarwinMachine_ {
    processor_cpu_load_info_t prev_load;
    processor_cpu_load_info_t curr_load;
 
+   io_service_t GPUService;
+
    ZfsArcStats zfs;
 } DarwinMachine;
 

darwin/Platform.c

@@ -10,6 +10,7 @@ in the source distribution for its full text.
 
 #include "darwin/Platform.h"
 
+#include <assert.h>
 #include <errno.h>
 #include <math.h>
 #include <stdlib.h>
@@ -38,6 +39,7 @@ in the source distribution for its full text.
 #include "DateMeter.h"
 #include "DateTimeMeter.h"
 #include "FileDescriptorMeter.h"
+#include "GPUMeter.h"
 #include "HostnameMeter.h"
 #include "LoadAverageMeter.h"
 #include "Macros.h"
@@ -144,6 +146,7 @@ const MeterClass* const Platform_meterTypes[] = {
    &DiskIOMeter_class,
    &NetworkIOMeter_class,
    &FileDescriptorMeter_class,
+   &GPUMeter_class,
    &BlankMeter_class,
    NULL
 };
@@ -284,6 +287,57 @@ double Platform_setCPUValues(Meter* mtr, unsigned int cpu) {
    return CLAMP(total, 0.0, 100.0);
 }
 
+void Platform_setGPUValues(Meter* mtr, double* totalUsage, unsigned long long* totalGPUTimeDiff) {
+   const Machine* host = mtr->host;
+   const DarwinMachine* dhost = (const DarwinMachine *)host;
+
+   assert(*totalGPUTimeDiff == -1ULL);
+   (void)totalGPUTimeDiff;
+
+   mtr->curItems = 1;
+   mtr->values[0] = NAN;
+
+   if (!dhost->GPUService)
+      return;
+
+   static uint64_t prevMonotonicMs;
+
+   // Ensure there is a small time interval between the creation of the
+   // CF property tables. If this function is called in quick successions
+   // (e.g. for multiple meter instances), we might get "0% utilization"
+   // as a result.
+   if (host->monotonicMs <= prevMonotonicMs) {
+      mtr->values[0] = *totalUsage;
+      return;
+   }
+
+   CFMutableDictionaryRef properties = NULL;
+   kern_return_t ret = IORegistryEntryCreateCFProperties(dhost->GPUService, &properties, kCFAllocatorDefault, kNilOptions);
+   if (ret != KERN_SUCCESS || !properties)
+      return;
+
+   CFDictionaryRef perfStats = CFDictionaryGetValue(properties, CFSTR("PerformanceStatistics"));
+   if (!perfStats)
+      goto cleanup;
+
+   assert(CFGetTypeID(perfStats) == CFDictionaryGetTypeID());
+
+   CFNumberRef deviceUtil = CFDictionaryGetValue(perfStats, CFSTR("Device Utilization %"));
+   if (!deviceUtil)
+      goto cleanup;
+
+   int device = -1;
+   CFNumberGetValue(deviceUtil, kCFNumberIntType, &device);
+   *totalUsage = (double)device;
+
+   prevMonotonicMs = host->monotonicMs;
+
+cleanup:
+   CFRelease(properties);
+
+   mtr->values[0] = *totalUsage;
+}
+
 void Platform_setMemoryValues(Meter* mtr) {
    const DarwinMachine* dhost = (const DarwinMachine*) mtr->host;
 #ifdef HAVE_STRUCT_VM_STATISTICS64

darwin/Platform.h

@@ -58,6 +58,8 @@ pid_t Platform_getMaxPid(void);
 
 double Platform_setCPUValues(Meter* mtr, unsigned int cpu);
 
+void Platform_setGPUValues(Meter* mtr, double* totalUsage, unsigned long long* totalGPUTimeDiff);
+
 void Platform_setMemoryValues(Meter* mtr);
 
 void Platform_setSwapValues(Meter* mtr);