process, v3/process: use SC_CLK_TCK sysconf value instead of hard-coding clock ticks

The github.com/tklauser/go-sysconf package is already a dependency used
in the cpu and v3/cpu packages to determine clock ticks using
`sysconf.Sysconf(sysconf.SC_CLK_TCK)`, see #1036. Use the same in
packages process and v3/process as well instead of hard-coding clock
ticks to 100.

process/process_darwin.go

@@ -14,6 +14,7 @@ import (
 	"github.com/shirou/gopsutil/cpu"
 	"github.com/shirou/gopsutil/internal/common"
 	"github.com/shirou/gopsutil/net"
+	"github.com/tklauser/go-sysconf"
 	"golang.org/x/sys/unix"
 )
 
@@ -27,9 +28,15 @@ const (
 	KernProcPathname = 12 // path to executable
 )
 
-const (
-	ClockTicks = 100 // C.sysconf(C._SC_CLK_TCK)
-)
+var ClockTicks = 100 // default value
+
+func init() {
+	clkTck, err := sysconf.Sysconf(sysconf.SC_CLK_TCK)
+	// ignore errors
+	if err == nil {
+		ClockTicks = int(clkTck)
+	}
+}
 
 type _Ctype_struct___0 struct {
 	Pad uint64
@@ -314,7 +321,7 @@ func convertCPUTimes(s string) (ret float64, err error) {
 	t += h * ClockTicks
 	h, err = strconv.Atoi(_t[1])
 	t += h
-	return float64(t) / ClockTicks, nil
+	return float64(t) / float64(ClockTicks), nil
 }
 
 func (p *Process) TimesWithContext(ctx context.Context) (*cpu.TimesStat, error) {

process/process_linux.go

@@ -18,15 +18,23 @@ import (
 	"github.com/shirou/gopsutil/cpu"
 	"github.com/shirou/gopsutil/internal/common"
 	"github.com/shirou/gopsutil/net"
+	"github.com/tklauser/go-sysconf"
 	"golang.org/x/sys/unix"
 )
 
 var PageSize = uint64(os.Getpagesize())
 
-const (
-	PrioProcess = 0   // linux/resource.h
-	ClockTicks  = 100 // C.sysconf(C._SC_CLK_TCK)
-)
+const PrioProcess = 0 // linux/resource.h
+
+var ClockTicks = 100 // default value
+
+func init() {
+	clkTck, err := sysconf.Sysconf(sysconf.SC_CLK_TCK)
+	// ignore errors
+	if err == nil {
+		ClockTicks = int(clkTck)
+	}
+}
 
 // MemoryInfoExStat is different between OSes
 type MemoryInfoExStat struct {
@@ -1031,9 +1039,9 @@ func (p *Process) fillFromTIDStatWithContext(ctx context.Context, tid int32) (ui
 
 	cpuTimes := &cpu.TimesStat{
 		CPU:    "cpu",
-		User:   float64(utime / ClockTicks),
-		System: float64(stime / ClockTicks),
-		Iowait: float64(iotime / ClockTicks),
+		User:   utime / float64(ClockTicks),
+		System: stime / float64(ClockTicks),
+		Iowait: iotime / float64(ClockTicks),
 	}
 
 	bootTime, _ := common.BootTimeWithContext(ctx)

v3/process/process_darwin.go

@@ -14,6 +14,7 @@ import (
 	"github.com/shirou/gopsutil/v3/cpu"
 	"github.com/shirou/gopsutil/v3/internal/common"
 	"github.com/shirou/gopsutil/v3/net"
+	"github.com/tklauser/go-sysconf"
 	"golang.org/x/sys/unix"
 )
 
@@ -27,9 +28,15 @@ const (
 	KernProcPathname = 12 // path to executable
 )
 
-const (
-	clockTicks = 100 // C.sysconf(C._SC_CLK_TCK)
-)
+var clockTicks = 100 // default value
+
+func init() {
+	clkTck, err := sysconf.Sysconf(sysconf.SC_CLK_TCK)
+	// ignore errors
+	if err == nil {
+		clockTicks = int(clkTck)
+	}
+}
 
 type _Ctype_struct___0 struct {
 	Pad uint64
@@ -314,7 +321,7 @@ func convertCPUTimes(s string) (ret float64, err error) {
 	t += h * clockTicks
 	h, err = strconv.Atoi(_t[1])
 	t += h
-	return float64(t) / clockTicks, nil
+	return float64(t) / float64(clockTicks), nil
 }
 
 func (p *Process) TimesWithContext(ctx context.Context) (*cpu.TimesStat, error) {

v3/process/process_linux.go

@@ -18,15 +18,23 @@ import (
 	"github.com/shirou/gopsutil/v3/cpu"
 	"github.com/shirou/gopsutil/v3/internal/common"
 	"github.com/shirou/gopsutil/v3/net"
+	"github.com/tklauser/go-sysconf"
 	"golang.org/x/sys/unix"
 )
 
 var pageSize = uint64(os.Getpagesize())
 
-const (
-	prioProcess = 0   // linux/resource.h
-	clockTicks  = 100 // C.sysconf(C._SC_CLK_TCK)
-)
+const prioProcess = 0 // linux/resource.h
+
+var clockTicks = 100 // default value
+
+func init() {
+	clkTck, err := sysconf.Sysconf(sysconf.SC_CLK_TCK)
+	// ignore errors
+	if err == nil {
+		clockTicks = int(clkTck)
+	}
+}
 
 // MemoryInfoExStat is different between OSes
 type MemoryInfoExStat struct {
@@ -1026,9 +1034,9 @@ func (p *Process) fillFromTIDStatWithContext(ctx context.Context, tid int32) (ui
 
 	cpuTimes := &cpu.TimesStat{
 		CPU:    "cpu",
-		User:   float64(utime / clockTicks),
-		System: float64(stime / clockTicks),
-		Iowait: float64(iotime / clockTicks),
+		User:   utime / float64(clockTicks),
+		System: stime / float64(clockTicks),
+		Iowait: iotime / float64(clockTicks),
 	}
 
 	bootTime, _ := common.BootTimeWithContext(ctx)