114 lines
2.7 KiB
Go
114 lines
2.7 KiB
Go
// Copyright 2022 PingCAP, Inc.
|
|
//
|
|
// 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 cpu
|
|
|
|
import (
|
|
"os"
|
|
"sync"
|
|
"time"
|
|
|
|
"github.com/cloudfoundry/gosigar"
|
|
"github.com/pingcap/log"
|
|
"github.com/pingcap/tidb/metrics"
|
|
"github.com/pingcap/tidb/util/cgroup"
|
|
"github.com/pingcap/tidb/util/mathutil"
|
|
"go.uber.org/atomic"
|
|
"go.uber.org/zap"
|
|
)
|
|
|
|
var cpuUsage atomic.Float64
|
|
|
|
// GetCPUUsage returns the cpu usage of the current process.
|
|
func GetCPUUsage() float64 {
|
|
return cpuUsage.Load()
|
|
}
|
|
|
|
// Observer is used to observe the cpu usage of the current process.
|
|
type Observer struct {
|
|
utime int64
|
|
stime int64
|
|
now int64
|
|
exit chan struct{}
|
|
cpu mathutil.ExponentialMovingAverage
|
|
wg sync.WaitGroup
|
|
}
|
|
|
|
// NewCPUObserver returns a cpu observer.
|
|
func NewCPUObserver() *Observer {
|
|
return &Observer{
|
|
exit: make(chan struct{}),
|
|
now: time.Now().UnixNano(),
|
|
cpu: *mathutil.NewExponentialMovingAverage(0.95, 10),
|
|
}
|
|
}
|
|
|
|
// Start starts the cpu observer.
|
|
func (c *Observer) Start() {
|
|
c.wg.Add(1)
|
|
go func() {
|
|
ticker := time.NewTicker(100 * time.Millisecond)
|
|
defer func() {
|
|
ticker.Stop()
|
|
c.wg.Done()
|
|
}()
|
|
for {
|
|
select {
|
|
case <-ticker.C:
|
|
curr := c.observe()
|
|
c.cpu.Add(curr)
|
|
cpuUsage.Store(c.cpu.Get())
|
|
metrics.EMACPUUsageGauge.Set(c.cpu.Get())
|
|
case <-c.exit:
|
|
return
|
|
}
|
|
}
|
|
}()
|
|
}
|
|
|
|
// Stop stops the cpu observer.
|
|
func (c *Observer) Stop() {
|
|
close(c.exit)
|
|
c.wg.Wait()
|
|
}
|
|
|
|
func (c *Observer) observe() float64 {
|
|
user, sys, err := getCPUTime()
|
|
if err != nil {
|
|
log.Error("getCPUTime", zap.Error(err))
|
|
}
|
|
cgroupCPU, _ := cgroup.GetCgroupCPU()
|
|
cpuShare := cgroupCPU.CPUShares()
|
|
now := time.Now().UnixNano()
|
|
dur := float64(now - c.now)
|
|
utime := user * 1e6
|
|
stime := sys * 1e6
|
|
urate := float64(utime-c.utime) / dur
|
|
srate := float64(stime-c.stime) / dur
|
|
c.now = now
|
|
c.utime = utime
|
|
c.stime = stime
|
|
return (srate + urate) / cpuShare
|
|
}
|
|
|
|
// getCPUTime returns the cumulative user/system time (in ms) since the process start.
|
|
func getCPUTime() (userTimeMillis, sysTimeMillis int64, err error) {
|
|
pid := os.Getpid()
|
|
cpuTime := sigar.ProcTime{}
|
|
if err := cpuTime.Get(pid); err != nil {
|
|
return 0, 0, err
|
|
}
|
|
return int64(cpuTime.User), int64(cpuTime.Sys), nil
|
|
}
|