From 6a572952f01e3bc46ff8d52de9f6bd3e63be8c90 Mon Sep 17 00:00:00 2001
From: Huan Wang <huwang@vmware.com>
Date: Mon, 14 Jun 2021 22:00:22 -0600
Subject: [PATCH] fix slow cpuinfo on multisocket config

updated win32_Processor struct to exclude loadpercentage field.
The loadpercentage takes linearly more time as the # of sockets
increases. By default vSphere maps 1 vCPU to 1 socket, resulting in very
poor performance when getting CPU info against, saying, 40 vCPU VM
(basically 40 sockets as seen by the VM).
---
 cpu/cpu_windows.go    | 16 +++++++++++++---
 v3/cpu/cpu_windows.go |  1 -
 2 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/cpu/cpu_windows.go b/cpu/cpu_windows.go
index ad1750b..a4ea585 100644
--- a/cpu/cpu_windows.go
+++ b/cpu/cpu_windows.go
@@ -5,6 +5,7 @@ package cpu
 import (
 	"context"
 	"fmt"
+	"strings"
 	"unsafe"
 
 	"github.com/StackExchange/wmi"
@@ -18,7 +19,14 @@ var (
 )
 
 type Win32_Processor struct {
-	LoadPercentage            *uint16
+	Win32_ProcessorWithoutLoadPct
+	LoadPercentage *uint16
+}
+
+// LoadPercentage takes a linearly more time as the number of sockets increases.
+// For vSphere by default corespersocket = 1, meaning for a 40 vCPU VM Get Processor Info
+// could take more than half a minute.
+type Win32_ProcessorWithoutLoadPct struct {
 	Family                    uint16
 	Manufacturer              string
 	Name                      string
@@ -104,8 +112,9 @@ func Info() ([]InfoStat, error) {
 
 func InfoWithContext(ctx context.Context) ([]InfoStat, error) {
 	var ret []InfoStat
-	var dst []Win32_Processor
+	var dst []Win32_ProcessorWithoutLoadPct
 	q := wmi.CreateQuery(&dst, "")
+	q = strings.ReplaceAll(q, "Win32_ProcessorWithoutLoadPct", "Win32_Processor")
 	if err := common.WMIQueryWithContext(ctx, q, &dst); err != nil {
 		return ret, err
 	}
@@ -242,8 +251,9 @@ func CountsWithContext(ctx context.Context, logical bool) (int, error) {
 	}
 	// physical cores https://github.com/giampaolo/psutil/blob/d01a9eaa35a8aadf6c519839e987a49d8be2d891/psutil/_psutil_windows.c#L499
 	// for the time being, try with unreliable and slow WMI call…
-	var dst []Win32_Processor
+	var dst []Win32_ProcessorWithoutLoadPct
 	q := wmi.CreateQuery(&dst, "")
+	q = strings.ReplaceAll(q, "Win32_ProcessorWithoutLoadPct", "Win32_Processor")
 	if err := common.WMIQueryWithContext(ctx, q, &dst); err != nil {
 		return 0, err
 	}
diff --git a/v3/cpu/cpu_windows.go b/v3/cpu/cpu_windows.go
index 8fd62ef..06335d9 100644
--- a/v3/cpu/cpu_windows.go
+++ b/v3/cpu/cpu_windows.go
@@ -18,7 +18,6 @@ var (
 )
 
 type win32_Processor struct {
-	LoadPercentage            *uint16
 	Family                    uint16
 	Manufacturer              string
 	Name                      string