forked from mirrors/gotosocial
acc333c40b
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.
106 lines
2.7 KiB
Go
106 lines
2.7 KiB
Go
/*
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Copyright The containerd Authors.
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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*/
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package cgroups
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import (
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"errors"
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"fmt"
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"path/filepath"
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)
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type Path func(subsystem Name) (string, error)
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func RootPath(subsystem Name) (string, error) {
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return "/", nil
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}
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// StaticPath returns a static path to use for all cgroups
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func StaticPath(path string) Path {
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return func(_ Name) (string, error) {
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return path, nil
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}
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}
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// NestedPath will nest the cgroups based on the calling processes cgroup
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// placing its child processes inside its own path
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func NestedPath(suffix string) Path {
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paths, err := ParseCgroupFile("/proc/self/cgroup")
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if err != nil {
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return errorPath(err)
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}
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return existingPath(paths, suffix)
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}
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// PidPath will return the correct cgroup paths for an existing process running inside a cgroup
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// This is commonly used for the Load function to restore an existing container
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func PidPath(pid int) Path {
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p := fmt.Sprintf("/proc/%d/cgroup", pid)
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paths, err := ParseCgroupFile(p)
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if err != nil {
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return errorPath(fmt.Errorf("parse cgroup file %s: %w", p, err))
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}
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return existingPath(paths, "")
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}
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// ErrControllerNotActive is returned when a controller is not supported or enabled
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var ErrControllerNotActive = errors.New("controller is not supported")
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func existingPath(paths map[string]string, suffix string) Path {
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// localize the paths based on the root mount dest for nested cgroups
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for n, p := range paths {
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dest, err := getCgroupDestination(n)
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if err != nil {
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return errorPath(err)
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}
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rel, err := filepath.Rel(dest, p)
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if err != nil {
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return errorPath(err)
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}
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if rel == "." {
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rel = dest
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}
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paths[n] = filepath.Join("/", rel)
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}
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return func(name Name) (string, error) {
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root, ok := paths[string(name)]
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if !ok {
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if root, ok = paths["name="+string(name)]; !ok {
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return "", ErrControllerNotActive
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}
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}
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if suffix != "" {
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return filepath.Join(root, suffix), nil
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}
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return root, nil
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}
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}
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func subPath(path Path, subName string) Path {
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return func(name Name) (string, error) {
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p, err := path(name)
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if err != nil {
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return "", err
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}
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return filepath.Join(p, subName), nil
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}
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}
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func errorPath(err error) Path {
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return func(_ Name) (string, error) {
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return "", err
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}
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}
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