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deploy: add -automaxprocs to reduce CPU and memory resources

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With the new `-automaxprocs` commandline parameter, Ceph-CSI will adjust
the GOMAXPROCS environment variable for the Golang runtime. The values
are based on the CPU quota that is given to the process. This can reduce
the number of threads that the Golang runtime spawns, which affects the
require amount of memory as well.

Updates: #5228
Signed-off-by: Niels de Vos <ndevos@ibm.com>
This commit is contained in:
Niels de Vos
2025-03-21 10:06:45 +01:00
committed by mergify[bot]
parent 0cb6771115
commit 4db8b6222c
18 changed files with 1074 additions and 0 deletions
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79
vendor/go.uber.org/automaxprocs/internal/cgroups/cgroup.go generated vendored Normal file
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// Copyright (c) 2017 Uber Technologies, Inc.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
//go:build linux
// +build linux
package cgroups
import (
"bufio"
"io"
"os"
"path/filepath"
"strconv"
)
// CGroup represents the data structure for a Linux control group.
type CGroup struct {
path string
}
// NewCGroup returns a new *CGroup from a given path.
func NewCGroup(path string) *CGroup {
return &CGroup{path: path}
}
// Path returns the path of the CGroup*.
func (cg *CGroup) Path() string {
return cg.path
}
// ParamPath returns the path of the given cgroup param under itself.
func (cg *CGroup) ParamPath(param string) string {
return filepath.Join(cg.path, param)
}
// readFirstLine reads the first line from a cgroup param file.
func (cg *CGroup) readFirstLine(param string) (string, error) {
paramFile, err := os.Open(cg.ParamPath(param))
if err != nil {
return "", err
}
defer paramFile.Close()
scanner := bufio.NewScanner(paramFile)
if scanner.Scan() {
return scanner.Text(), nil
}
if err := scanner.Err(); err != nil {
return "", err
}
return "", io.ErrUnexpectedEOF
}
// readInt parses the first line from a cgroup param file as int.
func (cg *CGroup) readInt(param string) (int, error) {
text, err := cg.readFirstLine(param)
if err != nil {
return 0, err
}
return strconv.Atoi(text)
}

118
vendor/go.uber.org/automaxprocs/internal/cgroups/cgroups.go generated vendored Normal file
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// Copyright (c) 2017 Uber Technologies, Inc.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
//go:build linux
// +build linux
package cgroups
const (
// _cgroupFSType is the Linux CGroup file system type used in
// `/proc/$PID/mountinfo`.
_cgroupFSType = "cgroup"
// _cgroupSubsysCPU is the CPU CGroup subsystem.
_cgroupSubsysCPU = "cpu"
// _cgroupSubsysCPUAcct is the CPU accounting CGroup subsystem.
_cgroupSubsysCPUAcct = "cpuacct"
// _cgroupSubsysCPUSet is the CPUSet CGroup subsystem.
_cgroupSubsysCPUSet = "cpuset"
// _cgroupSubsysMemory is the Memory CGroup subsystem.
_cgroupSubsysMemory = "memory"
// _cgroupCPUCFSQuotaUsParam is the file name for the CGroup CFS quota
// parameter.
_cgroupCPUCFSQuotaUsParam = "cpu.cfs_quota_us"
// _cgroupCPUCFSPeriodUsParam is the file name for the CGroup CFS period
// parameter.
_cgroupCPUCFSPeriodUsParam = "cpu.cfs_period_us"
)
const (
_procPathCGroup = "/proc/self/cgroup"
_procPathMountInfo = "/proc/self/mountinfo"
)
// CGroups is a map that associates each CGroup with its subsystem name.
type CGroups map[string]*CGroup
// NewCGroups returns a new *CGroups from given `mountinfo` and `cgroup` files
// under for some process under `/proc` file system (see also proc(5) for more
// information).
func NewCGroups(procPathMountInfo, procPathCGroup string) (CGroups, error) {
cgroupSubsystems, err := parseCGroupSubsystems(procPathCGroup)
if err != nil {
return nil, err
}
cgroups := make(CGroups)
newMountPoint := func(mp *MountPoint) error {
if mp.FSType != _cgroupFSType {
return nil
}
for _, opt := range mp.SuperOptions {
subsys, exists := cgroupSubsystems[opt]
if !exists {
continue
}
cgroupPath, err := mp.Translate(subsys.Name)
if err != nil {
return err
}
cgroups[opt] = NewCGroup(cgroupPath)
}
return nil
}
if err := parseMountInfo(procPathMountInfo, newMountPoint); err != nil {
return nil, err
}
return cgroups, nil
}
// NewCGroupsForCurrentProcess returns a new *CGroups instance for the current
// process.
func NewCGroupsForCurrentProcess() (CGroups, error) {
return NewCGroups(_procPathMountInfo, _procPathCGroup)
}
// CPUQuota returns the CPU quota applied with the CPU cgroup controller.
// It is a result of `cpu.cfs_quota_us / cpu.cfs_period_us`. If the value of
// `cpu.cfs_quota_us` was not set (-1), the method returns `(-1, nil)`.
func (cg CGroups) CPUQuota() (float64, bool, error) {
cpuCGroup, exists := cg[_cgroupSubsysCPU]
if !exists {
return -1, false, nil
}
cfsQuotaUs, err := cpuCGroup.readInt(_cgroupCPUCFSQuotaUsParam)
if defined := cfsQuotaUs > 0; err != nil || !defined {
return -1, defined, err
}
cfsPeriodUs, err := cpuCGroup.readInt(_cgroupCPUCFSPeriodUsParam)
if defined := cfsPeriodUs > 0; err != nil || !defined {
return -1, defined, err
}
return float64(cfsQuotaUs) / float64(cfsPeriodUs), true, nil
}

176
vendor/go.uber.org/automaxprocs/internal/cgroups/cgroups2.go generated vendored Normal file
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// Copyright (c) 2022 Uber Technologies, Inc.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
//go:build linux
// +build linux
package cgroups
import (
"bufio"
"errors"
"fmt"
"io"
"os"
"path"
"strconv"
"strings"
)
const (
// _cgroupv2CPUMax is the file name for the CGroup-V2 CPU max and period
// parameter.
_cgroupv2CPUMax = "cpu.max"
// _cgroupFSType is the Linux CGroup-V2 file system type used in
// `/proc/$PID/mountinfo`.
_cgroupv2FSType = "cgroup2"
_cgroupv2MountPoint = "/sys/fs/cgroup"
_cgroupV2CPUMaxDefaultPeriod = 100000
_cgroupV2CPUMaxQuotaMax = "max"
)
const (
_cgroupv2CPUMaxQuotaIndex = iota
_cgroupv2CPUMaxPeriodIndex
)
// ErrNotV2 indicates that the system is not using cgroups2.
var ErrNotV2 = errors.New("not using cgroups2")
// CGroups2 provides access to cgroups data for systems using cgroups2.
type CGroups2 struct {
mountPoint string
groupPath string
cpuMaxFile string
}
// NewCGroups2ForCurrentProcess builds a CGroups2 for the current process.
//
// This returns ErrNotV2 if the system is not using cgroups2.
func NewCGroups2ForCurrentProcess() (*CGroups2, error) {
return newCGroups2From(_procPathMountInfo, _procPathCGroup)
}
func newCGroups2From(mountInfoPath, procPathCGroup string) (*CGroups2, error) {
isV2, err := isCGroupV2(mountInfoPath)
if err != nil {
return nil, err
}
if !isV2 {
return nil, ErrNotV2
}
subsystems, err := parseCGroupSubsystems(procPathCGroup)
if err != nil {
return nil, err
}
// Find v2 subsystem by looking for the `0` id
var v2subsys *CGroupSubsys
for _, subsys := range subsystems {
if subsys.ID == 0 {
v2subsys = subsys
break
}
}
if v2subsys == nil {
return nil, ErrNotV2
}
return &CGroups2{
mountPoint: _cgroupv2MountPoint,
groupPath: v2subsys.Name,
cpuMaxFile: _cgroupv2CPUMax,
}, nil
}
func isCGroupV2(procPathMountInfo string) (bool, error) {
var (
isV2 bool
newMountPoint = func(mp *MountPoint) error {
isV2 = isV2 || (mp.FSType == _cgroupv2FSType && mp.MountPoint == _cgroupv2MountPoint)
return nil
}
)
if err := parseMountInfo(procPathMountInfo, newMountPoint); err != nil {
return false, err
}
return isV2, nil
}
// CPUQuota returns the CPU quota applied with the CPU cgroup2 controller.
// It is a result of reading cpu quota and period from cpu.max file.
// It will return `cpu.max / cpu.period`. If cpu.max is set to max, it returns
// (-1, false, nil)
func (cg *CGroups2) CPUQuota() (float64, bool, error) {
cpuMaxParams, err := os.Open(path.Join(cg.mountPoint, cg.groupPath, cg.cpuMaxFile))
if err != nil {
if os.IsNotExist(err) {
return -1, false, nil
}
return -1, false, err
}
defer cpuMaxParams.Close()
scanner := bufio.NewScanner(cpuMaxParams)
if scanner.Scan() {
fields := strings.Fields(scanner.Text())
if len(fields) == 0 || len(fields) > 2 {
return -1, false, fmt.Errorf("invalid format")
}
if fields[_cgroupv2CPUMaxQuotaIndex] == _cgroupV2CPUMaxQuotaMax {
return -1, false, nil
}
max, err := strconv.Atoi(fields[_cgroupv2CPUMaxQuotaIndex])
if err != nil {
return -1, false, err
}
var period int
if len(fields) == 1 {
period = _cgroupV2CPUMaxDefaultPeriod
} else {
period, err = strconv.Atoi(fields[_cgroupv2CPUMaxPeriodIndex])
if err != nil {
return -1, false, err
}
if period == 0 {
return -1, false, errors.New("zero value for period is not allowed")
}
}
return float64(max) / float64(period), true, nil
}
if err := scanner.Err(); err != nil {
return -1, false, err
}
return 0, false, io.ErrUnexpectedEOF
}

23
vendor/go.uber.org/automaxprocs/internal/cgroups/doc.go generated vendored Normal file
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// Copyright (c) 2017 Uber Technologies, Inc.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
// Package cgroups provides utilities to access Linux control group (CGroups)
// parameters (CPU quota, for example) for a given process.
package cgroups

52
vendor/go.uber.org/automaxprocs/internal/cgroups/errors.go generated vendored Normal file
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// Copyright (c) 2017 Uber Technologies, Inc.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
//go:build linux
// +build linux
package cgroups
import "fmt"
type cgroupSubsysFormatInvalidError struct {
line string
}
type mountPointFormatInvalidError struct {
line string
}
type pathNotExposedFromMountPointError struct {
mountPoint string
root string
path string
}
func (err cgroupSubsysFormatInvalidError) Error() string {
return fmt.Sprintf("invalid format for CGroupSubsys: %q", err.line)
}
func (err mountPointFormatInvalidError) Error() string {
return fmt.Sprintf("invalid format for MountPoint: %q", err.line)
}
func (err pathNotExposedFromMountPointError) Error() string {
return fmt.Sprintf("path %q is not a descendant of mount point root %q and cannot be exposed from %q", err.path, err.root, err.mountPoint)
}

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vendor/go.uber.org/automaxprocs/internal/cgroups/mountpoint.go generated vendored Normal file
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// Copyright (c) 2017 Uber Technologies, Inc.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
//go:build linux
// +build linux
package cgroups
import (
"bufio"
"os"
"path/filepath"
"strconv"
"strings"
)
const (
_mountInfoSep = " "
_mountInfoOptsSep = ","
_mountInfoOptionalFieldsSep = "-"
)
const (
_miFieldIDMountID = iota
_miFieldIDParentID
_miFieldIDDeviceID
_miFieldIDRoot
_miFieldIDMountPoint
_miFieldIDOptions
_miFieldIDOptionalFields
_miFieldCountFirstHalf
)
const (
_miFieldOffsetFSType = iota
_miFieldOffsetMountSource
_miFieldOffsetSuperOptions
_miFieldCountSecondHalf
)
const _miFieldCountMin = _miFieldCountFirstHalf + _miFieldCountSecondHalf
// MountPoint is the data structure for the mount points in
// `/proc/$PID/mountinfo`. See also proc(5) for more information.
type MountPoint struct {
MountID int
ParentID int
DeviceID string
Root string
MountPoint string
Options []string
OptionalFields []string
FSType string
MountSource string
SuperOptions []string
}
// NewMountPointFromLine parses a line read from `/proc/$PID/mountinfo` and
// returns a new *MountPoint.
func NewMountPointFromLine(line string) (*MountPoint, error) {
fields := strings.Split(line, _mountInfoSep)
if len(fields) < _miFieldCountMin {
return nil, mountPointFormatInvalidError{line}
}
mountID, err := strconv.Atoi(fields[_miFieldIDMountID])
if err != nil {
return nil, err
}
parentID, err := strconv.Atoi(fields[_miFieldIDParentID])
if err != nil {
return nil, err
}
for i, field := range fields[_miFieldIDOptionalFields:] {
if field == _mountInfoOptionalFieldsSep {
// End of optional fields.
fsTypeStart := _miFieldIDOptionalFields + i + 1
// Now we know where the optional fields end, split the line again with a
// limit to avoid issues with spaces in super options as present on WSL.
fields = strings.SplitN(line, _mountInfoSep, fsTypeStart+_miFieldCountSecondHalf)
if len(fields) != fsTypeStart+_miFieldCountSecondHalf {
return nil, mountPointFormatInvalidError{line}
}
miFieldIDFSType := _miFieldOffsetFSType + fsTypeStart
miFieldIDMountSource := _miFieldOffsetMountSource + fsTypeStart
miFieldIDSuperOptions := _miFieldOffsetSuperOptions + fsTypeStart
return &MountPoint{
MountID: mountID,
ParentID: parentID,
DeviceID: fields[_miFieldIDDeviceID],
Root: fields[_miFieldIDRoot],
MountPoint: fields[_miFieldIDMountPoint],
Options: strings.Split(fields[_miFieldIDOptions], _mountInfoOptsSep),
OptionalFields: fields[_miFieldIDOptionalFields:(fsTypeStart - 1)],
FSType: fields[miFieldIDFSType],
MountSource: fields[miFieldIDMountSource],
SuperOptions: strings.Split(fields[miFieldIDSuperOptions], _mountInfoOptsSep),
}, nil
}
}
return nil, mountPointFormatInvalidError{line}
}
// Translate converts an absolute path inside the *MountPoint's file system to
// the host file system path in the mount namespace the *MountPoint belongs to.
func (mp *MountPoint) Translate(absPath string) (string, error) {
relPath, err := filepath.Rel(mp.Root, absPath)
if err != nil {
return "", err
}
if relPath == ".." || strings.HasPrefix(relPath, "../") {
return "", pathNotExposedFromMountPointError{
mountPoint: mp.MountPoint,
root: mp.Root,
path: absPath,
}
}
return filepath.Join(mp.MountPoint, relPath), nil
}
// parseMountInfo parses procPathMountInfo (usually at `/proc/$PID/mountinfo`)
// and yields parsed *MountPoint into newMountPoint.
func parseMountInfo(procPathMountInfo string, newMountPoint func(*MountPoint) error) error {
mountInfoFile, err := os.Open(procPathMountInfo)
if err != nil {
return err
}
defer mountInfoFile.Close()
scanner := bufio.NewScanner(mountInfoFile)
for scanner.Scan() {
mountPoint, err := NewMountPointFromLine(scanner.Text())
if err != nil {
return err
}
if err := newMountPoint(mountPoint); err != nil {
return err
}
}
return scanner.Err()
}

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vendor/go.uber.org/automaxprocs/internal/cgroups/subsys.go generated vendored Normal file
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// Copyright (c) 2017 Uber Technologies, Inc.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
//go:build linux
// +build linux
package cgroups
import (
"bufio"
"os"
"strconv"
"strings"
)
const (
_cgroupSep = ":"
_cgroupSubsysSep = ","
)
const (
_csFieldIDID = iota
_csFieldIDSubsystems
_csFieldIDName
_csFieldCount
)
// CGroupSubsys represents the data structure for entities in
// `/proc/$PID/cgroup`. See also proc(5) for more information.
type CGroupSubsys struct {
ID int
Subsystems []string
Name string
}
// NewCGroupSubsysFromLine returns a new *CGroupSubsys by parsing a string in
// the format of `/proc/$PID/cgroup`
func NewCGroupSubsysFromLine(line string) (*CGroupSubsys, error) {
fields := strings.SplitN(line, _cgroupSep, _csFieldCount)
if len(fields) != _csFieldCount {
return nil, cgroupSubsysFormatInvalidError{line}
}
id, err := strconv.Atoi(fields[_csFieldIDID])
if err != nil {
return nil, err
}
cgroup := &CGroupSubsys{
ID: id,
Subsystems: strings.Split(fields[_csFieldIDSubsystems], _cgroupSubsysSep),
Name: fields[_csFieldIDName],
}
return cgroup, nil
}
// parseCGroupSubsystems parses procPathCGroup (usually at `/proc/$PID/cgroup`)
// and returns a new map[string]*CGroupSubsys.
func parseCGroupSubsystems(procPathCGroup string) (map[string]*CGroupSubsys, error) {
cgroupFile, err := os.Open(procPathCGroup)
if err != nil {
return nil, err
}
defer cgroupFile.Close()
scanner := bufio.NewScanner(cgroupFile)
subsystems := make(map[string]*CGroupSubsys)
for scanner.Scan() {
cgroup, err := NewCGroupSubsysFromLine(scanner.Text())
if err != nil {
return nil, err
}
for _, subsys := range cgroup.Subsystems {
subsystems[subsys] = cgroup
}
}
if err := scanner.Err(); err != nil {
return nil, err
}
return subsystems, nil
}