gotosocial/vendor/github.com/containerd/cgroups/control.go
Daniele Sluijters acc333c40b
[feature] Inherit resource limits from cgroups (#1336)
When GTS is running in a container runtime which has configured CPU or
memory limits or under an init system that uses cgroups to impose CPU
and memory limits the values the Go runtime sees for GOMAXPROCS and
GOMEMLIMIT are still based on the host resources, not the cgroup.

At least for the throttling middlewares which use GOMAXPROCS to
configure their queue size, this can result in GTS running with values
too big compared to the resources that will actuall be available to it.

This introduces 2 dependencies which can pick up resource contraints
from the current cgroup and tune the Go runtime accordingly. This should
result in the different queues being appropriately sized and in general
more predictable performance. These dependencies are a no-op on
non-Linux systems or if running in a cgroup that doesn't set a limit on
CPU or memory.

The automatic tuning of GOMEMLIMIT can be disabled by either explicitly
setting GOMEMLIMIT yourself or by setting AUTOMEMLIMIT=off. The
automatic tuning of GOMAXPROCS can similarly be counteracted by setting
GOMAXPROCS yourself.
2023-01-17 20:59:04 +00:00

100 lines
4.0 KiB
Go

/*
Copyright The containerd 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 cgroups
import (
"os"
v1 "github.com/containerd/cgroups/stats/v1"
specs "github.com/opencontainers/runtime-spec/specs-go"
)
type procType = string
const (
cgroupProcs procType = "cgroup.procs"
cgroupTasks procType = "tasks"
defaultDirPerm = 0755
)
// defaultFilePerm is a var so that the test framework can change the filemode
// of all files created when the tests are running. The difference between the
// tests and real world use is that files like "cgroup.procs" will exist when writing
// to a read cgroup filesystem and do not exist prior when running in the tests.
// this is set to a non 0 value in the test code
var defaultFilePerm = os.FileMode(0)
type Process struct {
// Subsystem is the name of the subsystem that the process / task is in.
Subsystem Name
// Pid is the process id of the process / task.
Pid int
// Path is the full path of the subsystem and location that the process / task is in.
Path string
}
type Task = Process
// Cgroup handles interactions with the individual groups to perform
// actions on them as them main interface to this cgroup package
type Cgroup interface {
// New creates a new cgroup under the calling cgroup
New(string, *specs.LinuxResources) (Cgroup, error)
// Add adds a process to the cgroup (cgroup.procs). Without additional arguments,
// the process is added to all the cgroup subsystems. When giving Add a list of
// subsystem names, the process is only added to those subsystems, provided that
// they are active in the targeted cgroup.
Add(Process, ...Name) error
// AddProc adds the process with the given id to the cgroup (cgroup.procs).
// Without additional arguments, the process with the given id is added to all
// the cgroup subsystems. When giving AddProc a list of subsystem names, the process
// id is only added to those subsystems, provided that they are active in the targeted
// cgroup.
AddProc(uint64, ...Name) error
// AddTask adds a process to the cgroup (tasks). Without additional arguments, the
// task is added to all the cgroup subsystems. When giving AddTask a list of subsystem
// names, the task is only added to those subsystems, provided that they are active in
// the targeted cgroup.
AddTask(Process, ...Name) error
// Delete removes the cgroup as a whole
Delete() error
// MoveTo moves all the processes under the calling cgroup to the provided one
// subsystems are moved one at a time
MoveTo(Cgroup) error
// Stat returns the stats for all subsystems in the cgroup
Stat(...ErrorHandler) (*v1.Metrics, error)
// Update updates all the subsystems with the provided resource changes
Update(resources *specs.LinuxResources) error
// Processes returns all the processes in a select subsystem for the cgroup
Processes(Name, bool) ([]Process, error)
// Tasks returns all the tasks in a select subsystem for the cgroup
Tasks(Name, bool) ([]Task, error)
// Freeze freezes or pauses all processes inside the cgroup
Freeze() error
// Thaw thaw or resumes all processes inside the cgroup
Thaw() error
// OOMEventFD returns the memory subsystem's event fd for OOM events
OOMEventFD() (uintptr, error)
// RegisterMemoryEvent returns the memory subsystems event fd for whatever memory event was
// registered for. Can alternatively register for the oom event with this method.
RegisterMemoryEvent(MemoryEvent) (uintptr, error)
// State returns the cgroups current state
State() State
// Subsystems returns all the subsystems in the cgroup
Subsystems() []Subsystem
}