VictoriaMetrics/vendor/github.com/prometheus/procfs/schedstat.go
Aliaksandr Valialkin 7f4fb34182 app/vmctl: move vmctl code from github.com/VictoriaMetrics/vmctl
It is better developing vmctl tool in VictoriaMetrics repository, so it could be released
together with the rest of vmutils tools such as vmalert, vmagent, vmbackup, vmrestore and vmauth.
2021-02-01 01:18:39 +02:00

118 lines
2.9 KiB
Go

// Copyright 2019 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"
"errors"
"os"
"regexp"
"strconv"
)
var (
cpuLineRE = regexp.MustCompile(`cpu(\d+) (\d+) (\d+) (\d+) (\d+) (\d+) (\d+) (\d+) (\d+) (\d+)`)
procLineRE = regexp.MustCompile(`(\d+) (\d+) (\d+)`)
)
// Schedstat contains scheduler statistics from /proc/schedstat
//
// See
// https://www.kernel.org/doc/Documentation/scheduler/sched-stats.txt
// for a detailed description of what these numbers mean.
//
// Note the current kernel documentation claims some of the time units are in
// jiffies when they are actually in nanoseconds since 2.6.23 with the
// introduction of CFS. A fix to the documentation is pending. See
// https://lore.kernel.org/patchwork/project/lkml/list/?series=403473
type Schedstat struct {
CPUs []*SchedstatCPU
}
// SchedstatCPU contains the values from one "cpu<N>" line
type SchedstatCPU struct {
CPUNum string
RunningNanoseconds uint64
WaitingNanoseconds uint64
RunTimeslices uint64
}
// ProcSchedstat contains the values from /proc/<pid>/schedstat
type ProcSchedstat struct {
RunningNanoseconds uint64
WaitingNanoseconds uint64
RunTimeslices uint64
}
// Schedstat reads data from /proc/schedstat
func (fs FS) Schedstat() (*Schedstat, error) {
file, err := os.Open(fs.proc.Path("schedstat"))
if err != nil {
return nil, err
}
defer file.Close()
stats := &Schedstat{}
scanner := bufio.NewScanner(file)
for scanner.Scan() {
match := cpuLineRE.FindStringSubmatch(scanner.Text())
if match != nil {
cpu := &SchedstatCPU{}
cpu.CPUNum = match[1]
cpu.RunningNanoseconds, err = strconv.ParseUint(match[8], 10, 64)
if err != nil {
continue
}
cpu.WaitingNanoseconds, err = strconv.ParseUint(match[9], 10, 64)
if err != nil {
continue
}
cpu.RunTimeslices, err = strconv.ParseUint(match[10], 10, 64)
if err != nil {
continue
}
stats.CPUs = append(stats.CPUs, cpu)
}
}
return stats, nil
}
func parseProcSchedstat(contents string) (stats ProcSchedstat, err error) {
match := procLineRE.FindStringSubmatch(contents)
if match != nil {
stats.RunningNanoseconds, err = strconv.ParseUint(match[1], 10, 64)
if err != nil {
return
}
stats.WaitingNanoseconds, err = strconv.ParseUint(match[2], 10, 64)
if err != nil {
return
}
stats.RunTimeslices, err = strconv.ParseUint(match[3], 10, 64)
return
}
err = errors.New("could not parse schedstat")
return
}