Correct timebase for non-x86 CPUs on Darwin

Fixes: #368

configure.ac

@@ -240,6 +240,11 @@ else
    AC_SEARCH_LIBS([keypad], [tinfo])
 fi
 
+if test "$my_htop_platform" = "darwin"; then
+   AC_CHECK_HEADERS([mach/mach_time.h])
+   AC_CHECK_FUNCS([mach_timebase_info])
+fi
+
 if test "$my_htop_platform" = "freebsd"; then
    AC_CHECK_LIB([kvm], [kvm_open], [], [missing_libraries="$missing_libraries libkvm"])
 fi

darwin/DarwinProcess.c

@@ -14,6 +14,7 @@ in the source distribution for its full text.
 #include <mach/mach.h>
 
 #include "CRT.h"
+#include "Platform.h"
 #include "Process.h"
 
 
@@ -248,7 +249,7 @@ void DarwinProcess_setFromLibprocPidinfo(DarwinProcess* proc, DarwinProcessList*
          uint64_t diff = (pti.pti_total_system - proc->stime)
                        + (pti.pti_total_user - proc->utime);
 
-         proc->super.percent_cpu = (double)diff * (double)dpl->super.cpuCount
+         proc->super.percent_cpu = (double)diff * (double)dpl->super.cpuCount * Platform_timebaseToNS
                                  / ((double)dpl->global_diff * 100000.0);
 
 //       fprintf(stderr, "%f %llu %llu %llu %llu %llu\n", proc->super.percent_cpu,

darwin/Platform.c

@@ -6,6 +6,8 @@ Released under the GNU GPLv2, see the COPYING file
 in the source distribution for its full text.
 */
 
+#include "config.h" // IWYU pragma: keep
+
 #include "Platform.h"
 
 #include <math.h>
@@ -32,6 +34,10 @@ in the source distribution for its full text.
 #include "zfs/ZfsArcMeter.h"
 #include "zfs/ZfsCompressedArcMeter.h"
 
+#ifdef HAVE_MACH_MACH_TIME_H
+#include <mach/mach_time.h>
+#endif
+
 
 ProcessField Platform_defaultFields[] = { PID, USER, PRIORITY, NICE, M_VIRT, M_RESIDENT, STATE, PERCENT_CPU, PERCENT_MEM, TIME, COMM, 0 };
 
@@ -135,8 +141,18 @@ const MeterClass* const Platform_meterTypes[] = {
 
 int Platform_numberOfFields = 100;
 
+double Platform_timebaseToNS = 1.0;
+
 void Platform_init(void) {
-   /* no platform-specific setup needed */
+   // Check if we can determine the timebase used on this system.
+   // If the API is unavailable assume we get our timebase in nanoseconds.
+#ifdef HAVE_MACH_TIMEBASE_INFO
+   mach_timebase_info_data_t info;
+   mach_timebase_info(&info);
+   Platform_timebaseToNS = (double)info.numer / (double)info.denom;
+#else
+   Platform_timebaseToNS = 1.0;
+#endif
 }
 
 void Platform_done(void) {

darwin/Platform.h

@@ -19,12 +19,15 @@ in the source distribution for its full text.
 #include "ProcessLocksScreen.h"
 #include "SignalsPanel.h"
 
+
 extern ProcessFieldData Process_fields[];
 
 extern ProcessField Platform_defaultFields[];
 
 extern int Platform_numberOfFields;
 
+extern double Platform_timebaseToNS;
+
 extern const SignalItem Platform_signals[];
 
 extern const unsigned int Platform_numberOfSignals;