[cpu][linux] Fix #849 implement giampaolo/psutil#1727 and test Counts against lscpu

cpu/cpu_linux.go

@@ -7,6 +7,7 @@ import (
 	"errors"
 	"fmt"
 	"os/exec"
+	"path/filepath"
 	"strconv"
 	"strings"
 
@@ -311,7 +312,23 @@ func CountsWithContext(ctx context.Context, logical bool) (int, error) {
 		}
 		return ret, nil
 	}
-	// physical cores https://github.com/giampaolo/psutil/blob/d01a9eaa35a8aadf6c519839e987a49d8be2d891/psutil/_pslinux.py#L628
+	// physical cores
+	// https://github.com/giampaolo/psutil/blob/122174a10b75c9beebe15f6c07dcf3afbe3b120d/psutil/_pslinux.py#L621-L629
+	var threadSiblingsLists = make(map[string]bool)
+	if files, err := filepath.Glob(common.HostSys("devices/system/cpu/cpu[0-9]*/topology/thread_siblings_list")); err == nil {
+		for _, file := range files {
+			lines, err := common.ReadLines(file)
+			if err != nil || len(lines) != 1 {
+				continue
+			}
+			threadSiblingsLists[lines[0]] = true
+		}
+		ret := len(threadSiblingsLists)
+		if ret != 0 {
+			return ret, nil
+		}
+	}
+	// https://github.com/giampaolo/psutil/blob/122174a10b75c9beebe15f6c07dcf3afbe3b120d/psutil/_pslinux.py#L631-L652
 	filename := common.HostProc("cpuinfo")
 	lines, err := common.ReadLines(filename)
 	if err != nil {

cpu/cpu_linux_test.go

@@ -2,6 +2,9 @@ package cpu
 
 import (
 	"os"
+	"os/exec"
+	"strconv"
+	"strings"
 	"testing"
 )
 
@@ -38,3 +41,53 @@ func TestCPUparseStatLine_424(t *testing.T) {
 	}
 	os.Setenv("HOST_PROC", orig)
 }
+
+func TestCPUCountsAgainstLscpu(t *testing.T) {
+	lscpu, err := exec.LookPath("lscpu")
+	if err != nil {
+		t.Skip("no lscpu to compare with")
+	}
+	cmd := exec.Command(lscpu)
+	cmd.Env = []string{"LC_ALL=C"}
+	out, err := cmd.Output()
+	if err != nil {
+		t.Errorf("error executing lscpu: %v", err)
+	}
+	var threadsPerCore, coresPerSocket, sockets int
+	lines := strings.Split(string(out), "\n")
+	for _, line := range lines {
+		fields := strings.Split(line, ":")
+		if len(fields) < 2 {
+			continue
+		}
+		switch fields[0] {
+		case "Thread(s) per core":
+			threadsPerCore, _ = strconv.Atoi(strings.TrimSpace(fields[1]))
+		case "Core(s) per socket":
+			coresPerSocket, _ = strconv.Atoi(strings.TrimSpace(fields[1]))
+		case "Socket(s)":
+			sockets, _ = strconv.Atoi(strings.TrimSpace(fields[1]))
+		}
+	}
+	if threadsPerCore == 0 || coresPerSocket == 0 || sockets == 0 {
+		t.Errorf("missing info from lscpu: threadsPerCore=%d coresPerSocket=%d sockets=%d", threadsPerCore, coresPerSocket, sockets)
+	}
+	expectedPhysical := coresPerSocket * sockets
+	expectedLogical := expectedPhysical * threadsPerCore
+	physical, err := Counts(false)
+	skipIfNotImplementedErr(t, err)
+	if err != nil {
+		t.Errorf("error %v", err)
+	}
+	logical, err := Counts(true)
+	skipIfNotImplementedErr(t, err)
+	if err != nil {
+		t.Errorf("error %v", err)
+	}
+	if expectedPhysical != physical {
+		t.Errorf("expected %v, got %v", expectedPhysical, physical)
+	}
+	if expectedLogical != logical {
+		t.Errorf("expected %v, got %v", expectedLogical, logical)
+	}
+}

cpu/cpu_test.go

@@ -71,8 +71,18 @@ func TestCpu_counts(t *testing.T) {
 		t.Errorf("error %v", err)
 	}
 	if v == 0 {
-		t.Errorf("could not get CPU counts: %v", v)
+		t.Errorf("could not get logical CPU counts: %v", v)
 	}
+	t.Logf("logical cores: %d", v)
+	v, err = Counts(false)
+	skipIfNotImplementedErr(t, err)
+	if err != nil {
+		t.Errorf("error %v", err)
+	}
+	if v == 0 {
+		t.Errorf("could not get physical CPU counts: %v", v)
+	}
+	t.Logf("physical cores: %d", v)
 }
 
 func TestCPUTimeStat_String(t *testing.T) {