lotus/extern/sector-storage/cgroups_linux.go
Clint Armstrong e2a1ca7caa Use cgroup limits in worker memory calculations
Worker processes may have memory limitations imposed by Systemd. But
/proc/meminfo shows the entire system memory regardless of these limits.
This results in the scheduler believing the worker has the entire system
memory avaliable and the worker being allocated too many tasks.

This change attempts to read cgroup memory limits for the worker
process. It supports cgroups v1 and v2, and compares cgroup limits
against the system memory and returns the most conservative values to
prevent the worker from being allocated too many tasks and potentially
triggering an OOM event.
2021-11-30 02:06:58 +01:00

118 lines
2.8 KiB
Go

//go:build linux
// +build linux
package sectorstorage
import (
"bufio"
"bytes"
"math"
"os"
"path/filepath"
"github.com/containerd/cgroups"
cgroupv2 "github.com/containerd/cgroups/v2"
)
func cgroupV2MountPoint() (string, error) {
f, err := os.Open("/proc/self/mountinfo")
if err != nil {
return "", err
}
defer f.Close()
scanner := bufio.NewScanner(f)
for scanner.Scan() {
fields := bytes.Fields(scanner.Bytes())
if len(fields) >= 9 && bytes.Equal(fields[8], []byte("cgroup2")) {
return string(fields[4]), nil
}
}
return "", cgroups.ErrMountPointNotExist
}
func cgroupV1Mem() (memoryMax, memoryUsed, swapMax, swapUsed uint64, err error) {
path := cgroups.NestedPath("")
if pid := os.Getpid(); pid == 1 {
path = cgroups.RootPath
}
c, err := cgroups.Load(cgroups.SingleSubsystem(cgroups.V1, cgroups.Memory), path)
if err != nil {
return 0, 0, 0, 0, err
}
stats, err := c.Stat()
if err != nil {
return 0, 0, 0, 0, err
}
if stats.Memory == nil {
return 0, 0, 0, 0, nil
}
if stats.Memory.Usage != nil {
memoryMax = stats.Memory.Usage.Limit
// Exclude cached files
memoryUsed = stats.Memory.Usage.Usage - stats.Memory.InactiveFile - stats.Memory.ActiveFile
}
if stats.Memory.Swap != nil {
swapMax = stats.Memory.Swap.Limit
swapUsed = stats.Memory.Swap.Usage
}
return memoryMax, memoryUsed, swapMax, swapUsed, nil
}
func cgroupV2MemFromPath(mp, path string) (memoryMax, memoryUsed, swapMax, swapUsed uint64, err error) {
c, err := cgroupv2.LoadManager(mp, path)
if err != nil {
return 0, 0, 0, 0, err
}
stats, err := c.Stat()
if err != nil {
return 0, 0, 0, 0, err
}
if stats.Memory != nil {
memoryMax = stats.Memory.UsageLimit
// Exclude memory used caching files
memoryUsed = stats.Memory.Usage - stats.Memory.File
swapMax = stats.Memory.SwapLimit
swapUsed = stats.Memory.SwapUsage
}
return memoryMax, memoryUsed, swapMax, swapUsed, nil
}
func cgroupV2Mem() (memoryMax, memoryUsed, swapMax, swapUsed uint64, err error) {
memoryMax = math.MaxUint64
swapMax = math.MaxUint64
path, err := cgroupv2.PidGroupPath(os.Getpid())
if err != nil {
return 0, 0, 0, 0, err
}
mp, err := cgroupV2MountPoint()
if err != nil {
return 0, 0, 0, 0, err
}
for path != "/" {
cgMemoryMax, cgMemoryUsed, cgSwapMax, cgSwapUsed, err := cgroupV2MemFromPath(mp, path)
if err != nil {
return 0, 0, 0, 0, err
}
if cgMemoryMax != 0 && cgMemoryMax < memoryMax {
log.Debugf("memory limited by cgroup %s: %v", path, cgMemoryMax)
memoryMax = cgMemoryMax
memoryUsed = cgMemoryUsed
}
if cgSwapMax != 0 && cgSwapMax < swapMax {
log.Debugf("swap limited by cgroup %s: %v", path, cgSwapMax)
swapMax = cgSwapMax
swapUsed = cgSwapUsed
}
path = filepath.Dir(path)
}
return memoryMax, memoryUsed, swapMax, swapUsed, nil
}