backport of commit 615e76ef3c23497f768ebd175f0c624d32aeece8 (#17993)

This pull request was automerged via backport-assistant

.changelog/17628.txt

@@ -0,0 +1,3 @@
+```release-note:improvement
+cpustats: Use config "cpu_total_compute" (if set) for all CPU statistics
+```

client/fingerprint/cpu.go

@@ -10,7 +10,8 @@ import (
 	"github.com/hashicorp/nomad/lib/cpuset"
 
 	"github.com/hashicorp/go-hclog"
-	"github.com/hashicorp/nomad/helper/stats"
+	"github.com/hashicorp/nomad/client/stats"
+	shelpers "github.com/hashicorp/nomad/helper/stats"
 	"github.com/hashicorp/nomad/nomad/structs"
 )
 
@@ -42,7 +43,7 @@ func NewCPUFingerprint(logger hclog.Logger) Fingerprint {
 }
 
 func (f *CPUFingerprint) Fingerprint(request *FingerprintRequest, response *FingerprintResponse) error {
-	f.initialize()
+	f.initialize(request)
 
 	f.setModelName(response)
 
@@ -61,8 +62,8 @@ func (f *CPUFingerprint) Fingerprint(request *FingerprintRequest, response *Fing
 	return nil
 }
 
-func (f *CPUFingerprint) initialize() {
-	if err := stats.Init(); err != nil {
+func (f *CPUFingerprint) initialize(request *FingerprintRequest) {
+	if err := stats.Init(uint64(request.Config.CpuCompute)); err != nil {
 		f.logger.Warn("failed initializing stats collector", "error", err)
 	}
 }
@@ -134,10 +135,8 @@ func (f *CPUFingerprint) setReservableCores(request *FingerprintRequest, respons
 func (f *CPUFingerprint) setTotalCompute(request *FingerprintRequest, response *FingerprintResponse) {
 	var ticks uint64
 	switch {
-	case request.Config.CpuCompute > 0:
-		ticks = uint64(request.Config.CpuCompute)
-	case stats.TotalTicksAvailable() > 0:
-		ticks = stats.TotalTicksAvailable()
+	case shelpers.CpuTotalTicks() > 0:
+		ticks = shelpers.CpuTotalTicks()
 	default:
 		ticks = defaultCPUTicks
 	}

client/fingerprint/env_aws.go

@@ -19,6 +19,7 @@ import (
 	log "github.com/hashicorp/go-hclog"
 
 	cleanhttp "github.com/hashicorp/go-cleanhttp"
+	"github.com/hashicorp/nomad/helper/stats"
 	"github.com/hashicorp/nomad/nomad/structs"
 )
 
@@ -185,6 +186,7 @@ func (f *EnvAWSFingerprint) Fingerprint(request *FingerprintRequest, response *F
 		if ticks := specs.Ticks(); request.Config.CpuCompute <= 0 {
 			response.AddAttribute("cpu.totalcompute", fmt.Sprintf("%d", ticks))
 			f.logger.Debug("setting ec2 cpu", "ticks", ticks)
+			stats.SetCpuTotalTicks(uint64(ticks))
 			resources = new(structs.Resources)
 			resources.CPU = ticks
 			if nodeResources == nil {

client/lib/resources/pid.go

@@ -4,7 +4,7 @@
 package resources
 
 import (
-	"github.com/hashicorp/nomad/client/stats"
+	"github.com/hashicorp/nomad/helper/stats"
 )
 
 // PIDs holds all of a task's pids and their cpu percentage calculators

client/stats/cpu.go

@@ -4,64 +4,115 @@
 package stats
 
 import (
-	"runtime"
+	"context"
+	"errors"
+	"fmt"
+	"sync"
 	"time"
 
-	shelpers "github.com/hashicorp/nomad/helper/stats"
+	"github.com/hashicorp/nomad/helper/stats"
 	"github.com/shirou/gopsutil/v3/cpu"
+	"github.com/shoenig/go-m1cpu"
 )
 
-// CpuStats calculates cpu usage percentage
-type CpuStats struct {
-	prevCpuTime float64
-	prevTime    time.Time
+const (
+	// cpuInfoTimeout is the timeout used when gathering CPU info. This is used
+	// to override the default timeout in gopsutil which has a tendency to
+	// timeout on Windows.
+	cpuInfoTimeout = 60 * time.Second
+)
 
-	totalCpus int
-}
+var (
+	cpuPowerCoreCount      int
+	cpuPowerCoreMHz        uint64
+	cpuEfficiencyCoreCount int
+	cpuEfficiencyCoreMHz   uint64
+	cpuModelName           string
+)
 
-// NewCpuStats returns a cpu stats calculator
-func NewCpuStats() *CpuStats {
-	numCpus := runtime.NumCPU()
-	cpuStats := &CpuStats{
-		totalCpus: numCpus,
-	}
-	return cpuStats
-}
+var (
+	detectedCpuTotalTicks uint64
+	initErr               error
+	onceLer               sync.Once
+)
 
-// Percent calculates the cpu usage percentage based on the current cpu usage
-// and the previous cpu usage where usage is given as time in nanoseconds spend
-// in the cpu
-func (c *CpuStats) Percent(cpuTime float64) float64 {
-	now := time.Now()
+func Init(configCpuTotalCompute uint64) error {
+	onceLer.Do(func() {
+		switch {
+		case m1cpu.IsAppleSilicon():
+			cpuModelName = m1cpu.ModelName()
+			cpuPowerCoreCount = m1cpu.PCoreCount()
+			cpuPowerCoreMHz = m1cpu.PCoreHz() / 1_000_000
+			cpuEfficiencyCoreCount = m1cpu.ECoreCount()
+			cpuEfficiencyCoreMHz = m1cpu.ECoreHz() / 1_000_000
+			bigTicks := uint64(cpuPowerCoreCount) * cpuPowerCoreMHz
+			littleTicks := uint64(cpuEfficiencyCoreCount) * cpuEfficiencyCoreMHz
+			detectedCpuTotalTicks = bigTicks + littleTicks
+		default:
+			// for now, all other cpu types assume only power cores
+			// todo: this is already not true for Intel 13th generation
 
-	if c.prevCpuTime == 0.0 {
-		// invoked first time
-		c.prevCpuTime = cpuTime
-		c.prevTime = now
-		return 0.0
+			var err error
+			if cpuPowerCoreCount, err = cpu.Counts(true); err != nil {
+				initErr = errors.Join(initErr, fmt.Errorf("failed to detect number of CPU cores: %w", err))
 			}
 
-	timeDelta := now.Sub(c.prevTime).Nanoseconds()
-	ret := c.calculatePercent(c.prevCpuTime, cpuTime, timeDelta)
-	c.prevCpuTime = cpuTime
-	c.prevTime = now
-	return ret
-}
+			ctx, cancel := context.WithTimeout(context.Background(), cpuInfoTimeout)
+			defer cancel()
 
-// TicksConsumed calculates the total ticks consumes by the process across all
-// cpu cores
-func (c *CpuStats) TicksConsumed(percent float64) float64 {
-	return (percent / 100) * float64(shelpers.TotalTicksAvailable()) / float64(c.totalCpus)
-}
-
-func (c *CpuStats) calculatePercent(t1, t2 float64, timeDelta int64) float64 {
-	vDelta := t2 - t1
-	if timeDelta <= 0 || vDelta <= 0.0 {
-		return 0.0
+			var cpuInfoStats []cpu.InfoStat
+			if cpuInfoStats, err = cpu.InfoWithContext(ctx); err != nil {
+				initErr = errors.Join(initErr, fmt.Errorf("Unable to obtain CPU information: %w", err))
 			}
 
-	overall_percent := (vDelta / float64(timeDelta)) * 100.0
-	return overall_percent
+			for _, infoStat := range cpuInfoStats {
+				cpuModelName = infoStat.ModelName
+				if uint64(infoStat.Mhz) > cpuPowerCoreMHz {
+					cpuPowerCoreMHz = uint64(infoStat.Mhz)
+				}
+			}
+
+			// compute ticks using only power core, until we add support for
+			// detecting little cores on non-apple platforms
+			detectedCpuTotalTicks = uint64(cpuPowerCoreCount) * cpuPowerCoreMHz
+
+			initErr = err
+		}
+
+		stats.SetCpuTotalTicks(detectedCpuTotalTicks)
+	})
+
+	// override the computed value with the config value if it is set
+	if configCpuTotalCompute > 0 {
+		stats.SetCpuTotalTicks(configCpuTotalCompute)
+	}
+
+	return initErr
+}
+
+// CPUNumCores returns the number of CPU cores available.
+//
+// This is represented with two values - (Power (P), Efficiency (E)) so we can
+// correctly compute total compute for processors with asymetric cores such as
+// Apple Silicon.
+//
+// For platforms with symetric cores (or where we do not correcly detect asymetric
+// cores), all cores are presented as P cores.
+func CPUNumCores() (int, int) {
+	return cpuPowerCoreCount, cpuEfficiencyCoreCount
+}
+
+// CPUMHzPerCore returns the MHz per CPU (P, E) core type.
+//
+// As with CPUNumCores, asymetric core detection currently only works with
+// Apple Silicon CPUs.
+func CPUMHzPerCore() (uint64, uint64) {
+	return cpuPowerCoreMHz, cpuEfficiencyCoreMHz
+}
+
+// CPUModelName returns the model name of the CPU.
+func CPUModelName() string {
+	return cpuModelName
 }
 
 func (h *HostStatsCollector) collectCPUStats() (cpus []*CPUStats, totalTicks float64, err error) {
@@ -79,7 +130,7 @@ func (h *HostStatsCollector) collectCPUStats() (cpus []*CPUStats, totalTicks flo
 			h.statsCalculator[cpuStat.CPU] = percentCalculator
 		}
 		idle, user, system, total := percentCalculator.Calculate(cpuStat)
-		ticks := (total / 100.0) * (float64(shelpers.TotalTicksAvailable()) / float64(len(cpuStats)))
+		ticks := (total / 100.0) * (float64(stats.CpuTotalTicks()) / float64(len(cpuStats)))
 		cs[idx] = &CPUStats{
 			CPU:          cpuStat.CPU,
 			User:         user,

client/stats/cpu_darwin_test.go

@@ -32,7 +32,7 @@ func TestCPU_CPUModelName(t *testing.T) {
 	must.NotEq(t, "", name)
 }
 
-func TestCPU_CPUTotalTicksAvailable(t *testing.T) {
-	ticks := TotalTicksAvailable()
+func TestCPU_CPUCpuTotalTicks(t *testing.T) {
+	ticks := CpuTotalTicks()
 	must.Positive(t, ticks)
 }

client/stats/cpu_test.go

@@ -7,32 +7,17 @@ import (
 	"math"
 	"os"
 	"testing"
-	"time"
 
 	"github.com/hashicorp/nomad/ci"
-	shelpers "github.com/hashicorp/nomad/helper/stats"
 	"github.com/hashicorp/nomad/helper/testlog"
 	"github.com/stretchr/testify/assert"
 )
 
-func TestCpuStatsPercent(t *testing.T) {
-	ci.Parallel(t)
-
-	cs := NewCpuStats()
-	cs.Percent(79.7)
-	time.Sleep(1 * time.Second)
-	percent := cs.Percent(80.69)
-	expectedPercent := 98.00
-	if percent < expectedPercent && percent > (expectedPercent+1.00) {
-		t.Fatalf("expected: %v, actual: %v", expectedPercent, percent)
-	}
-}
-
 func TestHostStats_CPU(t *testing.T) {
 	ci.Parallel(t)
 
 	assert := assert.New(t)
-	assert.Nil(shelpers.Init())
+	assert.Nil(Init(0))
 
 	logger := testlog.HCLogger(t)
 	cwd, err := os.Getwd()

drivers/docker/util/stats_posix.go

@@ -56,7 +56,7 @@ func DockerStatsToTaskResourceUsage(s *docker.Stats) *cstructs.TaskResourceUsage
 	cs.UserMode = CalculateCPUPercent(
 		s.CPUStats.CPUUsage.UsageInUsermode, s.PreCPUStats.CPUUsage.UsageInUsermode,
 		s.CPUStats.CPUUsage.TotalUsage, s.PreCPUStats.CPUUsage.TotalUsage, runtime.NumCPU())
-	cs.TotalTicks = (cs.Percent / 100) * float64(stats.TotalTicksAvailable()) / float64(runtime.NumCPU())
+	cs.TotalTicks = (cs.Percent / 100) * float64(stats.CpuTotalTicks()) / float64(runtime.NumCPU())
 
 	return &cstructs.TaskResourceUsage{
 		ResourceUsage: &cstructs.ResourceUsage{

drivers/docker/util/stats_windows.go

@@ -45,7 +45,7 @@ func DockerStatsToTaskResourceUsage(s *docker.Stats) *cstructs.TaskResourceUsage
 		ThrottledPeriods: s.CPUStats.ThrottlingData.ThrottledPeriods,
 		ThrottledTime:    s.CPUStats.ThrottlingData.ThrottledTime,
 		Percent:          cpuPercent,
-		TotalTicks:       (cpuPercent / 100) * float64(stats.TotalTicksAvailable()) / float64(runtime.NumCPU()),
+		TotalTicks:       (cpuPercent / 100) * float64(stats.CpuTotalTicks()) / float64(runtime.NumCPU()),
 		Measured:         DockerMeasuredCPUStats,
 	}
 

drivers/shared/executor/executor.go

@@ -23,9 +23,8 @@ import (
 	"github.com/hashicorp/nomad/client/allocdir"
 	"github.com/hashicorp/nomad/client/lib/fifo"
 	"github.com/hashicorp/nomad/client/lib/resources"
-	"github.com/hashicorp/nomad/client/stats"
 	cstructs "github.com/hashicorp/nomad/client/structs"
-	shelpers "github.com/hashicorp/nomad/helper/stats"
+	"github.com/hashicorp/nomad/helper/stats"
 	"github.com/hashicorp/nomad/plugins/drivers"
 	"github.com/syndtr/gocapability/capability"
 )
@@ -259,11 +258,9 @@ type UniversalExecutor struct {
 }
 
 // NewExecutor returns an Executor
-func NewExecutor(logger hclog.Logger) Executor {
+func NewExecutor(logger hclog.Logger, cpuTotalTicks uint64) Executor {
 	logger = logger.Named("executor")
-	if err := shelpers.Init(); err != nil {
-		logger.Error("unable to initialize stats", "error", err)
-	}
+	stats.SetCpuTotalTicks(cpuTotalTicks)
 
 	return &UniversalExecutor{
 		logger:         logger,

drivers/shared/executor/executor_basic.go

@@ -13,10 +13,10 @@ import (
 	"github.com/hashicorp/nomad/plugins/drivers"
 )
 
-func NewExecutorWithIsolation(logger hclog.Logger) Executor {
+func NewExecutorWithIsolation(logger hclog.Logger, cpuTotalTicks uint64) Executor {
 	logger = logger.Named("executor")
 	logger.Error("isolation executor is not supported on this platform, using default")
-	return NewExecutor(logger)
+	return NewExecutor(logger, cpuTotalTicks)
 }
 
 func (e *UniversalExecutor) configureResourceContainer(_ int) error { return nil }

drivers/shared/executor/executor_linux.go

@@ -24,10 +24,9 @@ import (
 	"github.com/hashicorp/nomad/client/allocdir"
 	"github.com/hashicorp/nomad/client/lib/cgutil"
 	"github.com/hashicorp/nomad/client/lib/resources"
-	"github.com/hashicorp/nomad/client/stats"
 	cstructs "github.com/hashicorp/nomad/client/structs"
 	"github.com/hashicorp/nomad/drivers/shared/capabilities"
-	shelpers "github.com/hashicorp/nomad/helper/stats"
+	"github.com/hashicorp/nomad/helper/stats"
 	"github.com/hashicorp/nomad/helper/uuid"
 	"github.com/hashicorp/nomad/nomad/structs"
 	"github.com/hashicorp/nomad/plugins/drivers"
@@ -71,11 +70,10 @@ type LibcontainerExecutor struct {
 	exitState      *ProcessState
 }
 
-func NewExecutorWithIsolation(logger hclog.Logger) Executor {
+func NewExecutorWithIsolation(logger hclog.Logger, cpuTotalTicks uint64) Executor {
 	logger = logger.Named("isolated_executor")
-	if err := shelpers.Init(); err != nil {
-		logger.Error("unable to initialize stats", "error", err)
-	}
+	stats.SetCpuTotalTicks(cpuTotalTicks)
+
 	return &LibcontainerExecutor{
 		id:             strings.ReplaceAll(uuid.Generate(), "-", "_"),
 		logger:         logger,

drivers/shared/executor/executor_linux_test.go

@@ -147,7 +147,7 @@ func TestExecutor_Isolation_PID_and_IPC_hostMode(t *testing.T) {
 	execCmd.ModePID = "host" // disable PID namespace
 	execCmd.ModeIPC = "host" // disable IPC namespace
 
-	executor := NewExecutorWithIsolation(testlog.HCLogger(t))
+	executor := NewExecutorWithIsolation(testlog.HCLogger(t), 0)
 	defer executor.Shutdown("SIGKILL", 0)
 
 	ps, err := executor.Launch(execCmd)
@@ -190,7 +190,7 @@ func TestExecutor_IsolationAndConstraints(t *testing.T) {
 	execCmd.ModePID = "private"
 	execCmd.ModeIPC = "private"
 
-	executor := NewExecutorWithIsolation(testlog.HCLogger(t))
+	executor := NewExecutorWithIsolation(testlog.HCLogger(t), 0)
 	defer executor.Shutdown("SIGKILL", 0)
 
 	ps, err := executor.Launch(execCmd)
@@ -282,7 +282,7 @@ func TestExecutor_CgroupPaths(t *testing.T) {
 
 	execCmd.ResourceLimits = true
 
-	executor := NewExecutorWithIsolation(testlog.HCLogger(t))
+	executor := NewExecutorWithIsolation(testlog.HCLogger(t), 0)
 	defer executor.Shutdown("SIGKILL", 0)
 
 	ps, err := executor.Launch(execCmd)
@@ -344,7 +344,7 @@ func TestExecutor_CgroupPathsAreDestroyed(t *testing.T) {
 
 	execCmd.ResourceLimits = true
 
-	executor := NewExecutorWithIsolation(testlog.HCLogger(t))
+	executor := NewExecutorWithIsolation(testlog.HCLogger(t), 0)
 	defer executor.Shutdown("SIGKILL", 0)
 
 	ps, err := executor.Launch(execCmd)
@@ -547,7 +547,7 @@ func TestExecutor_EscapeContainer(t *testing.T) {
 
 	execCmd.ResourceLimits = true
 
-	executor := NewExecutorWithIsolation(testlog.HCLogger(t))
+	executor := NewExecutorWithIsolation(testlog.HCLogger(t), 0)
 	defer executor.Shutdown("SIGKILL", 0)
 
 	_, err := executor.Launch(execCmd)
@@ -597,7 +597,7 @@ func TestExecutor_DoesNotInheritOomScoreAdj(t *testing.T) {
 	execCmd.Cmd = "/bin/bash"
 	execCmd.Args = []string{"-c", "cat /proc/self/oom_score_adj"}
 
-	executor := NewExecutorWithIsolation(testlog.HCLogger(t))
+	executor := NewExecutorWithIsolation(testlog.HCLogger(t), 0)
 	defer executor.Shutdown("SIGKILL", 0)
 
 	_, err = executor.Launch(execCmd)
@@ -691,7 +691,7 @@ CapAmb: 0000000000000400`,
 				execCmd.Capabilities = capsAllowed
 			}
 
-			executor := NewExecutorWithIsolation(testlog.HCLogger(t))
+			executor := NewExecutorWithIsolation(testlog.HCLogger(t), 0)
 			defer executor.Shutdown("SIGKILL", 0)
 
 			_, err := executor.Launch(execCmd)
@@ -739,7 +739,7 @@ func TestExecutor_ClientCleanup(t *testing.T) {
 	execCmd, allocDir := testExecCmd.command, testExecCmd.allocDir
 	defer allocDir.Destroy()
 
-	executor := NewExecutorWithIsolation(testlog.HCLogger(t))
+	executor := NewExecutorWithIsolation(testlog.HCLogger(t), 0)
 	defer executor.Shutdown("", 0)
 
 	// Need to run a command which will produce continuous output but not
@@ -864,7 +864,7 @@ func TestUniversalExecutor_NoCgroup(t *testing.T) {
 	execCmd.BasicProcessCgroup = false
 	execCmd.ResourceLimits = false
 
-	executor := NewExecutor(testlog.HCLogger(t))
+	executor := NewExecutor(testlog.HCLogger(t), 0)
 	defer executor.Shutdown("SIGKILL", 0)
 
 	_, err = executor.Launch(execCmd)

drivers/shared/executor/executor_plugin.go

@@ -17,13 +17,14 @@ type ExecutorPlugin struct {
 	plugin.NetRPCUnsupportedPlugin
 	logger        hclog.Logger
 	fsIsolation   bool
+	cpuTotalTicks uint64
 }
 
 func (p *ExecutorPlugin) GRPCServer(broker *plugin.GRPCBroker, s *grpc.Server) error {
 	if p.fsIsolation {
-		proto.RegisterExecutorServer(s, &grpcExecutorServer{impl: NewExecutorWithIsolation(p.logger)})
+		proto.RegisterExecutorServer(s, &grpcExecutorServer{impl: NewExecutorWithIsolation(p.logger, p.cpuTotalTicks)})
 	} else {
-		proto.RegisterExecutorServer(s, &grpcExecutorServer{impl: NewExecutor(p.logger)})
+		proto.RegisterExecutorServer(s, &grpcExecutorServer{impl: NewExecutor(p.logger, p.cpuTotalTicks)})
 	}
 	return nil
 }

drivers/shared/executor/executor_test.go

@@ -36,7 +36,7 @@ import (
 var executorFactories = map[string]executorFactory{}
 
 type executorFactory struct {
-	new              func(hclog.Logger) Executor
+	new              func(hclog.Logger, uint64) Executor
 	configureExecCmd func(*testing.T, *ExecCommand)
 }
 
@@ -150,7 +150,7 @@ func TestExecutor_Start_Invalid(t *testing.T) {
 			execCmd.Args = []string{"1"}
 			factory.configureExecCmd(t, execCmd)
 			defer allocDir.Destroy()
-			executor := factory.new(testlog.HCLogger(t))
+			executor := factory.new(testlog.HCLogger(t), 0)
 			defer executor.Shutdown("", 0)
 
 			_, err := executor.Launch(execCmd)
@@ -170,7 +170,7 @@ func TestExecutor_Start_Wait_Failure_Code(t *testing.T) {
 			execCmd.Args = []string{"-c", "sleep 1; /bin/date fail"}
 			factory.configureExecCmd(t, execCmd)
 			defer allocDir.Destroy()
-			executor := factory.new(testlog.HCLogger(t))
+			executor := factory.new(testlog.HCLogger(t), 0)
 			defer executor.Shutdown("", 0)
 
 			ps, err := executor.Launch(execCmd)
@@ -195,7 +195,7 @@ func TestExecutor_Start_Wait(t *testing.T) {
 			factory.configureExecCmd(t, execCmd)
 
 			defer allocDir.Destroy()
-			executor := factory.new(testlog.HCLogger(t))
+			executor := factory.new(testlog.HCLogger(t), 0)
 			defer executor.Shutdown("", 0)
 
 			ps, err := executor.Launch(execCmd)
@@ -232,7 +232,7 @@ func TestExecutor_Start_Wait_Children(t *testing.T) {
 			factory.configureExecCmd(t, execCmd)
 
 			defer allocDir.Destroy()
-			executor := factory.new(testlog.HCLogger(t))
+			executor := factory.new(testlog.HCLogger(t), 0)
 			defer executor.Shutdown("SIGKILL", 0)
 
 			ps, err := executor.Launch(execCmd)
@@ -273,7 +273,7 @@ func TestExecutor_WaitExitSignal(t *testing.T) {
 			factory.configureExecCmd(t, execCmd)
 
 			defer allocDir.Destroy()
-			executor := factory.new(testlog.HCLogger(t))
+			executor := factory.new(testlog.HCLogger(t), 0)
 			defer executor.Shutdown("", 0)
 
 			pState, err := executor.Launch(execCmd)
@@ -331,7 +331,7 @@ func TestExecutor_Start_Kill(t *testing.T) {
 			factory.configureExecCmd(t, execCmd)
 
 			defer allocDir.Destroy()
-			executor := factory.new(testlog.HCLogger(t))
+			executor := factory.new(testlog.HCLogger(t), 0)
 			defer executor.Shutdown("", 0)
 
 			ps, err := executor.Launch(execCmd)
@@ -536,7 +536,7 @@ func TestExecutor_Start_Kill_Immediately_NoGrace(t *testing.T) {
 			execCmd.Args = []string{"100"}
 			factory.configureExecCmd(t, execCmd)
 			defer allocDir.Destroy()
-			executor := factory.new(testlog.HCLogger(t))
+			executor := factory.new(testlog.HCLogger(t), 0)
 			defer executor.Shutdown("", 0)
 
 			ps, err := executor.Launch(execCmd)
@@ -572,7 +572,7 @@ func TestExecutor_Start_Kill_Immediately_WithGrace(t *testing.T) {
 			execCmd.Args = []string{"100"}
 			factory.configureExecCmd(t, execCmd)
 			defer allocDir.Destroy()
-			executor := factory.new(testlog.HCLogger(t))
+			executor := factory.new(testlog.HCLogger(t), 0)
 			defer executor.Shutdown("", 0)
 
 			ps, err := executor.Launch(execCmd)
@@ -618,7 +618,7 @@ func TestExecutor_Start_NonExecutableBinaries(t *testing.T) {
 			execCmd.Cmd = nonExecutablePath
 			factory.configureExecCmd(t, execCmd)
 
-			executor := factory.new(testlog.HCLogger(t))
+			executor := factory.new(testlog.HCLogger(t), 0)
 			defer executor.Shutdown("", 0)
 
 			// need to configure path in chroot with that file if using isolation executor

drivers/shared/executor/pid_collector.go

@@ -11,7 +11,7 @@ import (
 
 	hclog "github.com/hashicorp/go-hclog"
 	"github.com/hashicorp/nomad/client/lib/resources"
-	"github.com/hashicorp/nomad/client/stats"
+	"github.com/hashicorp/nomad/helper/stats"
 	"github.com/hashicorp/nomad/plugins/drivers"
 	ps "github.com/mitchellh/go-ps"
 	"github.com/shirou/gopsutil/v3/process"

drivers/shared/executor/plugins.go

@@ -22,13 +22,18 @@ type ExecutorConfig struct {
 	// FSIsolation if set will use an executor implementation that support
 	// filesystem isolation
 	FSIsolation bool
+
+	// cpuTotalTicks is the total CPU compute. It should be given as Cores * MHz
+	// (2 Cores * 2 Ghz = 4000)
+	CpuTotalTicks uint64
 }
 
-func GetPluginMap(logger hclog.Logger, fsIsolation bool) map[string]plugin.Plugin {
+func GetPluginMap(logger hclog.Logger, fsIsolation bool, cpuTotalTicks uint64) map[string]plugin.Plugin {
 	return map[string]plugin.Plugin{
 		"executor": &ExecutorPlugin{
 			logger:        logger,
 			fsIsolation:   fsIsolation,
+			cpuTotalTicks: cpuTotalTicks,
 		},
 	}
 }

drivers/shared/executor/utils.go

@@ -13,6 +13,7 @@ import (
 	hclog "github.com/hashicorp/go-hclog"
 	plugin "github.com/hashicorp/go-plugin"
 	"github.com/hashicorp/nomad/drivers/shared/executor/proto"
+	"github.com/hashicorp/nomad/helper/stats"
 	"github.com/hashicorp/nomad/plugins/base"
 )
 
@@ -31,6 +32,7 @@ const (
 func CreateExecutor(logger hclog.Logger, driverConfig *base.ClientDriverConfig,
 	executorConfig *ExecutorConfig) (Executor, *plugin.Client, error) {
 
+	executorConfig.CpuTotalTicks = stats.CpuTotalTicks()
 	c, err := json.Marshal(executorConfig)
 	if err != nil {
 		return nil, nil, fmt.Errorf("unable to create executor config: %v", err)
@@ -43,6 +45,7 @@ func CreateExecutor(logger hclog.Logger, driverConfig *base.ClientDriverConfig,
 	p := &ExecutorPlugin{
 		logger:        logger,
 		fsIsolation:   executorConfig.FSIsolation,
+		cpuTotalTicks: executorConfig.CpuTotalTicks,
 	}
 
 	config := &plugin.ClientConfig{
@@ -75,7 +78,7 @@ func ReattachToExecutor(reattachConfig *plugin.ReattachConfig, logger hclog.Logg
 	config := &plugin.ClientConfig{
 		HandshakeConfig:  base.Handshake,
 		Reattach:         reattachConfig,
-		Plugins:          GetPluginMap(logger, false),
+		Plugins:          GetPluginMap(logger, false, stats.CpuTotalTicks()),
 		AllowedProtocols: []plugin.Protocol{plugin.ProtocolGRPC},
 		Logger:           logger.Named("executor"),
 	}

drivers/shared/executor/z_executor_cmd.go

@@ -49,6 +49,7 @@ func init() {
 			Plugins: GetPluginMap(
 				logger,
 				executorConfig.FSIsolation,
+				executorConfig.CpuTotalTicks,
 			),
 			GRPCServer: plugin.DefaultGRPCServer,
 			Logger:     logger,

helper/stats/cpu.go

@@ -4,109 +4,73 @@
 package stats
 
 import (
-	"context"
-	"errors"
-	"fmt"
-	"sync"
+	"runtime"
 	"time"
-
-	"github.com/shirou/gopsutil/v3/cpu"
-	"github.com/shoenig/go-m1cpu"
-)
-
-const (
-	// cpuInfoTimeout is the timeout used when gathering CPU info. This is used
-	// to override the default timeout in gopsutil which has a tendency to
-	// timeout on Windows.
-	cpuInfoTimeout = 60 * time.Second
 )
 
 var (
-	cpuPowerCoreCount      int
-	cpuPowerCoreMHz        uint64
-	cpuEfficiencyCoreCount int
-	cpuEfficiencyCoreMHz   uint64
 	cpuTotalTicks uint64
-	cpuModelName           string
 )
 
-var (
-	initErr error
-	onceLer sync.Once
-)
+// CpuStats calculates cpu usage percentage
+type CpuStats struct {
+	prevCpuTime float64
+	prevTime    time.Time
 
-func Init() error {
-	onceLer.Do(func() {
-		switch {
-		case m1cpu.IsAppleSilicon():
-			cpuModelName = m1cpu.ModelName()
-			cpuPowerCoreCount = m1cpu.PCoreCount()
-			cpuPowerCoreMHz = m1cpu.PCoreHz() / 1_000_000
-			cpuEfficiencyCoreCount = m1cpu.ECoreCount()
-			cpuEfficiencyCoreMHz = m1cpu.ECoreHz() / 1_000_000
-			bigTicks := uint64(cpuPowerCoreCount) * cpuPowerCoreMHz
-			littleTicks := uint64(cpuEfficiencyCoreCount) * cpuEfficiencyCoreMHz
-			cpuTotalTicks = bigTicks + littleTicks
-		default:
-			// for now, all other cpu types assume only power cores
-			// todo: this is already not true for Intel 13th generation
-
-			var err error
-			if cpuPowerCoreCount, err = cpu.Counts(true); err != nil {
-				initErr = errors.Join(initErr, fmt.Errorf("failed to detect number of CPU cores: %w", err))
-			}
-
-			ctx, cancel := context.WithTimeout(context.Background(), cpuInfoTimeout)
-			defer cancel()
-
-			var cpuInfoStats []cpu.InfoStat
-			if cpuInfoStats, err = cpu.InfoWithContext(ctx); err != nil {
-				initErr = errors.Join(initErr, fmt.Errorf("Unable to obtain CPU information: %w", err))
-			}
-
-			for _, infoStat := range cpuInfoStats {
-				cpuModelName = infoStat.ModelName
-				if uint64(infoStat.Mhz) > cpuPowerCoreMHz {
-					cpuPowerCoreMHz = uint64(infoStat.Mhz)
-				}
-			}
-
-			// compute ticks using only power core, until we add support for
-			// detecting little cores on non-apple platforms
-			cpuTotalTicks = uint64(cpuPowerCoreCount) * cpuPowerCoreMHz
-
-			initErr = err
-		}
-	})
-	return initErr
+	totalCpus int
 }
 
-// CPUNumCores returns the number of CPU cores available.
-//
-// This is represented with two values - (Power (P), Efficiency (E)) so we can
-// correctly compute total compute for processors with asymetric cores such as
-// Apple Silicon.
-//
-// For platforms with symetric cores (or where we do not correcly detect asymetric
-// cores), all cores are presented as P cores.
-func CPUNumCores() (int, int) {
-	return cpuPowerCoreCount, cpuEfficiencyCoreCount
+// NewCpuStats returns a cpu stats calculator
+func NewCpuStats() *CpuStats {
+	numCpus := runtime.NumCPU()
+	cpuStats := &CpuStats{
+		totalCpus: numCpus,
+	}
+	return cpuStats
 }
 
-// CPUMHzPerCore returns the MHz per CPU (P, E) core type.
-//
-// As with CPUNumCores, asymetric core detection currently only works with
-// Apple Silicon CPUs.
-func CPUMHzPerCore() (uint64, uint64) {
-	return cpuPowerCoreMHz, cpuEfficiencyCoreMHz
+// Percent calculates the cpu usage percentage based on the current cpu usage
+// and the previous cpu usage where usage is given as time in nanoseconds spend
+// in the cpu
+func (c *CpuStats) Percent(cpuTime float64) float64 {
+	now := time.Now()
+
+	if c.prevCpuTime == 0.0 {
+		// invoked first time
+		c.prevCpuTime = cpuTime
+		c.prevTime = now
+		return 0.0
+	}
+
+	timeDelta := now.Sub(c.prevTime).Nanoseconds()
+	ret := c.calculatePercent(c.prevCpuTime, cpuTime, timeDelta)
+	c.prevCpuTime = cpuTime
+	c.prevTime = now
+	return ret
 }
 
-// CPUModelName returns the model name of the CPU.
-func CPUModelName() string {
-	return cpuModelName
+// TicksConsumed calculates the total ticks consumes by the process across all
+// cpu cores
+func (c *CpuStats) TicksConsumed(percent float64) float64 {
+	return (percent / 100) * float64(CpuTotalTicks()) / float64(c.totalCpus)
 }
 
-// TotalTicksAvailable calculates the total MHz available across all cores.
+func (c *CpuStats) calculatePercent(t1, t2 float64, timeDelta int64) float64 {
+	vDelta := t2 - t1
+	if timeDelta <= 0 || vDelta <= 0.0 {
+		return 0.0
+	}
+
+	overall_percent := (vDelta / float64(timeDelta)) * 100.0
+	return overall_percent
+}
+
+// Set the total ticks available across all cores.
+func SetCpuTotalTicks(newCpuTotalTicks uint64) {
+	cpuTotalTicks = newCpuTotalTicks
+}
+
+// CpuTotalTicks calculates the total MHz available across all cores.
 //
 // Where asymetric cores are correctly detected, the total ticks is the sum of
 // the performance across both core types.
@@ -114,6 +78,6 @@ func CPUModelName() string {
 // Where asymetric cores are not correctly detected (such as Intel 13th gen),
 // the total ticks available is over-estimated, as we assume all cores are P
 // cores.
-func TotalTicksAvailable() uint64 {
+func CpuTotalTicks() uint64 {
 	return cpuTotalTicks
 }

helper/stats/cpu_test.go

@@ -0,0 +1,24 @@
+// Copyright (c) HashiCorp, Inc.
+// SPDX-License-Identifier: MPL-2.0
+
+package stats
+
+import (
+	"testing"
+	"time"
+
+	"github.com/hashicorp/nomad/ci"
+)
+
+func TestCpuStatsPercent(t *testing.T) {
+	ci.Parallel(t)
+
+	cs := NewCpuStats()
+	cs.Percent(79.7)
+	time.Sleep(1 * time.Second)
+	percent := cs.Percent(80.69)
+	expectedPercent := 98.00
+	if percent < expectedPercent && percent > (expectedPercent+1.00) {
+		t.Fatalf("expected: %v, actual: %v", expectedPercent, percent)
+	}
+}