gitea/vendor/github.com/prometheus/procfs/stat.go

233 lines
6.7 KiB
Go

// Copyright 2018 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package procfs
import (
"bufio"
"fmt"
"io"
"os"
"strconv"
"strings"
)
// CPUStat shows how much time the cpu spend in various stages.
type CPUStat struct {
User float64
Nice float64
System float64
Idle float64
Iowait float64
IRQ float64
SoftIRQ float64
Steal float64
Guest float64
GuestNice float64
}
// SoftIRQStat represent the softirq statistics as exported in the procfs stat file.
// A nice introduction can be found at https://0xax.gitbooks.io/linux-insides/content/interrupts/interrupts-9.html
// It is possible to get per-cpu stats by reading /proc/softirqs
type SoftIRQStat struct {
Hi uint64
Timer uint64
NetTx uint64
NetRx uint64
Block uint64
BlockIoPoll uint64
Tasklet uint64
Sched uint64
Hrtimer uint64
Rcu uint64
}
// Stat represents kernel/system statistics.
type Stat struct {
// Boot time in seconds since the Epoch.
BootTime uint64
// Summed up cpu statistics.
CPUTotal CPUStat
// Per-CPU statistics.
CPU []CPUStat
// Number of times interrupts were handled, which contains numbered and unnumbered IRQs.
IRQTotal uint64
// Number of times a numbered IRQ was triggered.
IRQ []uint64
// Number of times a context switch happened.
ContextSwitches uint64
// Number of times a process was created.
ProcessCreated uint64
// Number of processes currently running.
ProcessesRunning uint64
// Number of processes currently blocked (waiting for IO).
ProcessesBlocked uint64
// Number of times a softirq was scheduled.
SoftIRQTotal uint64
// Detailed softirq statistics.
SoftIRQ SoftIRQStat
}
// NewStat returns kernel/system statistics read from /proc/stat.
func NewStat() (Stat, error) {
fs, err := NewFS(DefaultMountPoint)
if err != nil {
return Stat{}, err
}
return fs.NewStat()
}
// Parse a cpu statistics line and returns the CPUStat struct plus the cpu id (or -1 for the overall sum).
func parseCPUStat(line string) (CPUStat, int64, error) {
cpuStat := CPUStat{}
var cpu string
count, err := fmt.Sscanf(line, "%s %f %f %f %f %f %f %f %f %f %f",
&cpu,
&cpuStat.User, &cpuStat.Nice, &cpuStat.System, &cpuStat.Idle,
&cpuStat.Iowait, &cpuStat.IRQ, &cpuStat.SoftIRQ, &cpuStat.Steal,
&cpuStat.Guest, &cpuStat.GuestNice)
if err != nil && err != io.EOF {
return CPUStat{}, -1, fmt.Errorf("couldn't parse %s (cpu): %s", line, err)
}
if count == 0 {
return CPUStat{}, -1, fmt.Errorf("couldn't parse %s (cpu): 0 elements parsed", line)
}
cpuStat.User /= userHZ
cpuStat.Nice /= userHZ
cpuStat.System /= userHZ
cpuStat.Idle /= userHZ
cpuStat.Iowait /= userHZ
cpuStat.IRQ /= userHZ
cpuStat.SoftIRQ /= userHZ
cpuStat.Steal /= userHZ
cpuStat.Guest /= userHZ
cpuStat.GuestNice /= userHZ
if cpu == "cpu" {
return cpuStat, -1, nil
}
cpuID, err := strconv.ParseInt(cpu[3:], 10, 64)
if err != nil {
return CPUStat{}, -1, fmt.Errorf("couldn't parse %s (cpu/cpuid): %s", line, err)
}
return cpuStat, cpuID, nil
}
// Parse a softirq line.
func parseSoftIRQStat(line string) (SoftIRQStat, uint64, error) {
softIRQStat := SoftIRQStat{}
var total uint64
var prefix string
_, err := fmt.Sscanf(line, "%s %d %d %d %d %d %d %d %d %d %d %d",
&prefix, &total,
&softIRQStat.Hi, &softIRQStat.Timer, &softIRQStat.NetTx, &softIRQStat.NetRx,
&softIRQStat.Block, &softIRQStat.BlockIoPoll,
&softIRQStat.Tasklet, &softIRQStat.Sched,
&softIRQStat.Hrtimer, &softIRQStat.Rcu)
if err != nil {
return SoftIRQStat{}, 0, fmt.Errorf("couldn't parse %s (softirq): %s", line, err)
}
return softIRQStat, total, nil
}
// NewStat returns an information about current kernel/system statistics.
func (fs FS) NewStat() (Stat, error) {
// See https://www.kernel.org/doc/Documentation/filesystems/proc.txt
f, err := os.Open(fs.Path("stat"))
if err != nil {
return Stat{}, err
}
defer f.Close()
stat := Stat{}
scanner := bufio.NewScanner(f)
for scanner.Scan() {
line := scanner.Text()
parts := strings.Fields(scanner.Text())
// require at least <key> <value>
if len(parts) < 2 {
continue
}
switch {
case parts[0] == "btime":
if stat.BootTime, err = strconv.ParseUint(parts[1], 10, 64); err != nil {
return Stat{}, fmt.Errorf("couldn't parse %s (btime): %s", parts[1], err)
}
case parts[0] == "intr":
if stat.IRQTotal, err = strconv.ParseUint(parts[1], 10, 64); err != nil {
return Stat{}, fmt.Errorf("couldn't parse %s (intr): %s", parts[1], err)
}
numberedIRQs := parts[2:]
stat.IRQ = make([]uint64, len(numberedIRQs))
for i, count := range numberedIRQs {
if stat.IRQ[i], err = strconv.ParseUint(count, 10, 64); err != nil {
return Stat{}, fmt.Errorf("couldn't parse %s (intr%d): %s", count, i, err)
}
}
case parts[0] == "ctxt":
if stat.ContextSwitches, err = strconv.ParseUint(parts[1], 10, 64); err != nil {
return Stat{}, fmt.Errorf("couldn't parse %s (ctxt): %s", parts[1], err)
}
case parts[0] == "processes":
if stat.ProcessCreated, err = strconv.ParseUint(parts[1], 10, 64); err != nil {
return Stat{}, fmt.Errorf("couldn't parse %s (processes): %s", parts[1], err)
}
case parts[0] == "procs_running":
if stat.ProcessesRunning, err = strconv.ParseUint(parts[1], 10, 64); err != nil {
return Stat{}, fmt.Errorf("couldn't parse %s (procs_running): %s", parts[1], err)
}
case parts[0] == "procs_blocked":
if stat.ProcessesBlocked, err = strconv.ParseUint(parts[1], 10, 64); err != nil {
return Stat{}, fmt.Errorf("couldn't parse %s (procs_blocked): %s", parts[1], err)
}
case parts[0] == "softirq":
softIRQStats, total, err := parseSoftIRQStat(line)
if err != nil {
return Stat{}, err
}
stat.SoftIRQTotal = total
stat.SoftIRQ = softIRQStats
case strings.HasPrefix(parts[0], "cpu"):
cpuStat, cpuID, err := parseCPUStat(line)
if err != nil {
return Stat{}, err
}
if cpuID == -1 {
stat.CPUTotal = cpuStat
} else {
for int64(len(stat.CPU)) <= cpuID {
stat.CPU = append(stat.CPU, CPUStat{})
}
stat.CPU[cpuID] = cpuStat
}
}
}
if err := scanner.Err(); err != nil {
return Stat{}, fmt.Errorf("couldn't parse %s: %s", f.Name(), err)
}
return stat, nil
}