cpu: Store stats in heap and show top 4 usr cpu

cpu/cpu.go

@@ -2,59 +2,61 @@ package cpu
 
 import (
  "bufio"
+ "container/heap"
  "fmt"
  "os"
  "strconv"
  "strings"
 )
 
-type CpuInfo struct {
- Cores int
- Mhz float64
- Siblings int // this is threads
- Stats []*CpuTime
- OldStats []*CpuTime
-}
+// For /proc/stat field order
+type cputimeidx int
 
-func (cpu *CpuInfo) calcStats() {
- if len(cpu.OldStats) == 0 {
- // TODO - be smarter than just skipping it the first time through?
- return
- }
+const (
+ cputNr cputimeidx = iota
+ cputUser
+ cputNice
+ cputSys
+ cputIdle
+ cputIowait
+ cputIrq
+ cputSoftirq
+ cputSteal
+ cputGuest
+ cputGuest_nice
+)
+
+type CpuTime struct {
+ nr string // cpu number
+ // times are in USER_HZ which is defined by sysconf(_SC_CLK_TCK)
+ user int // time in user mode
+ nice int
+ sys int
+ idle int
+ iowait int
+ irq int
+ softirq int
+ steal int
+ guest int
+ guest_nice int
 }
 
-func (cpu *CpuInfo) InfoPrint() string {
- // clktck, err := sysconf.Sysconf(sysconf.SC_CLK_TCK)
- // if err != nil {
- // log.Fatal("error getting system clock", err)
- // }
- if len(cpu.OldStats) == 0 {
- // TODO - be smarter than just skipping it the first time through?
- return ""
- }
- prev_cpu := cpu.OldStats[0]
- cur_cpu := cpu.Stats[0]
-
- cpu_total := cur_cpu.user + cur_cpu.nice + cur_cpu.sys + cur_cpu.idle + cur_cpu.iowait + cur_cpu.irq + cur_cpu.softirq + cur_cpu.steal + cur_cpu.guest + cur_cpu.guest_nice
- old_total := prev_cpu.user + prev_cpu.nice + prev_cpu.sys + prev_cpu.idle + prev_cpu.iowait + prev_cpu.irq + prev_cpu.softirq + prev_cpu.steal + prev_cpu.guest + prev_cpu.guest_nice
- nl := float32(cpu_total - old_total)
- s := fmt.Sprintf(
- "vc:%d\tf: %.2f\t\tusr:%.2f sys:%.2f: idle:%.2f iowait:%.2f irq:%.2f softirq:%.2f steal:%.2f guest:%.2f gnice:%.2f",
- cpu.Siblings,
- cpu.Mhz/1000,
- float32((cur_cpu.user-prev_cpu.user))/nl,
- float32(cur_cpu.sys-prev_cpu.sys)/nl,
- float32(cur_cpu.idle-prev_cpu.idle)/nl,
- float32(cur_cpu.iowait-prev_cpu.iowait)/nl,
- float32(cur_cpu.irq-prev_cpu.irq)/nl,
- float32(cur_cpu.softirq-prev_cpu.softirq)/nl,
- float32(cur_cpu.steal-prev_cpu.steal)/nl,
- float32(cur_cpu.guest-prev_cpu.guest)/nl,
- float32(cur_cpu.guest_nice-prev_cpu.guest_nice)/nl,
- )
- return s
+// Used to store calculated fractional values
+type CpuStat struct {
+ nr string // cpu number
+ user float32
+ nice float32
+ sys float32
+ idle float32
+ iowait float32
+ irq float32
+ softirq float32
+ steal float32
+ guest float32
+ guest_nice float32
 }
 
+// Lines in the /proc/cpuinfo file
 type cpuinfoidx int
 
 const (
@@ -88,36 +90,97 @@ const (
  cinfcinf_power_management
 )
 
-type CpuTime struct {
- nr string // cpu number
- // times are in USER_HZ which is defined by sysconf(_SC_CLK_TCK)
- user int // time in user mode
- nice int
- sys int
- idle int
- iowait int
- irq int
- softirq int
- steal int
- guest int
- guest_nice int
+// Holds all cpu information including previous, current counts and estimated values for percent time spent in each.
+type CpuInfo struct {
+ Cores int
+ Mhz float64
+ Siblings int // this is threads
+ Stats []*CpuTime
+ OldStats []*CpuTime
+ calcstats *calculatedstats
 }
 
-type cputimeidx int
+// This will be a heap to quickly get cpu sorted by user time
+type calculatedstats []*CpuStat
 
-const (
- cputNr cputimeidx = iota
- cputUser // time in user mode
- cputNice
- cputSys
- cputIdle
- cputIowait
- cputIrq
- cputSoftirq
- cputSteal
- cputGuest
- cputGuest_nice
-)
+func (h calculatedstats) Len() int { return len(h) }
+
+// TODO: use configurable method
+func (h calculatedstats) Less(i, j int) bool { return h[i].user > h[j].user }
+func (h calculatedstats) Swap(i, j int) { h[i], h[j] = h[j], h[i] }
+func (h *calculatedstats) Push(x any) { *h = append(*h, x.(*CpuStat)) }
+func (h *calculatedstats) Pop() any {
+ old := *h
+ n := len(old)
+ x := old[n-1]
+ *h = old[0 : n-1]
+ return x
+}
+
+func (cpu *CpuTime) total() int {
+ return cpu.user + cpu.nice + cpu.sys + cpu.idle + cpu.iowait + cpu.irq + cpu.softirq + cpu.steal + cpu.guest + cpu.guest_nice
+}
+
+func (cpu *CpuInfo) estimate() {
+ if len(cpu.OldStats) == 0 {
+ return
+ }
+ prev := cpu.OldStats
+ cur := cpu.Stats
+
+ cpu.calcstats = new(calculatedstats)
+ heap.Init(cpu.calcstats)
+
+ for i := range cur {
+ c := new(CpuStat)
+ denom := float32(cur[i].total() - prev[i].total())
+ c.nr = cur[i].nr
+ c.user = float32((cur[i].user - prev[i].user)) / denom
+ c.sys = float32((cur[i].sys - prev[i].sys)) / denom
+ c.idle = float32((cur[i].idle - prev[i].idle)) / denom
+ c.iowait = float32((cur[i].iowait - prev[i].iowait)) / denom
+ c.irq = float32((cur[i].irq - prev[i].irq)) / denom
+ c.softirq = float32((cur[i].softirq - prev[i].softirq)) / denom
+ c.steal = float32((cur[i].steal - prev[i].steal)) / denom
+ c.guest = float32((cur[i].guest - prev[i].guest)) / denom
+ c.guest_nice = float32((cur[i].guest_nice - prev[i].guest_nice)) / denom
+ heap.Push(cpu.calcstats, c)
+ }
+}
+
+func (cpu *CpuInfo) InfoPrint(num_cpus int) string {
+ // clktck, err := sysconf.Sysconf(sysconf.SC_CLK_TCK)
+ // if err != nil {
+ // log.Fatal("error getting system clock", err)
+ // }
+ cpu.estimate()
+ if len(cpu.OldStats) == 0 {
+ // TODO: - be smarter than just skipping it the first time through?
+ return ""
+ }
+
+ var sb strings.Builder
+ sb.WriteString(fmt.Sprintf("vc:%d\tf: %.2f\n", cpu.Siblings, cpu.Mhz/1000))
+
+ for i := 0; i < num_cpus; i++ {
+ c := heap.Pop(cpu.calcstats).(*CpuStat)
+ sb.WriteString(
+ fmt.Sprintf(
+ "%s: usr:%.2f sys:%.2f: idle:%.2f iowait:%.2f irq:%.2f softirq:%.2f steal:%.2f guest:%.2f gnice:%.2f\n",
+ c.nr,
+ c.user,
+ c.sys,
+ c.idle,
+ c.iowait,
+ c.irq,
+ c.softirq,
+ c.steal,
+ c.guest,
+ c.guest_nice,
+ ))
+ }
+ return sb.String()
+}
 
 func get_cpuinfo() (*CpuInfo, error) {
  f, err := os.Open("/proc/cpuinfo")

synopsys.go

@@ -63,7 +63,7 @@ func main() {
  "up:%s %s cpu:%s\nmem: %s\n",
  ut.HoursMinutes(),
  ld.InfoPrint(),
- c.InfoPrint(),
+ c.InfoPrint(4),
  m.InfoPrint(),
  )
  }