3d20fa9309
(this was introduced in 44240116aa)
Setting the oom-score-adj to -1000 is only possible if the parent process
either has no score set, or if the score is set to -1000.
However, the current implementation of GetOOMScoreAdj conflates situations
where either _no_ oom-score is set, _or_ oom-score is set, but set to 0.
In the latter case, the test would fail:
--- FAIL: TestSetOOMScoreBoundaries (0.01s)
oom_linux_test.go:79: assertion failed: 0 (adjustment int) != -1000 (OOMScoreAdjMin int)
FAIL
To prevent failures in this situation, skip that part of the test in the
above situation.
Also update the description of GetOOMScoreAdj to clarify its behavior.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
84 lines
2.5 KiB
Go
84 lines
2.5 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 sys
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import (
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"fmt"
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"io/ioutil"
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"os"
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"strconv"
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"strings"
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"github.com/containerd/containerd/pkg/userns"
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"golang.org/x/sys/unix"
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)
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const (
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// OOMScoreAdjMin is from OOM_SCORE_ADJ_MIN https://github.com/torvalds/linux/blob/v5.10/include/uapi/linux/oom.h#L9
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OOMScoreAdjMin = -1000
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// OOMScoreAdjMax is from OOM_SCORE_ADJ_MAX https://github.com/torvalds/linux/blob/v5.10/include/uapi/linux/oom.h#L10
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OOMScoreAdjMax = 1000
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)
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// AdjustOOMScore sets the oom score for the provided pid. If the provided score
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// is out of range (-1000 - 1000), it is clipped to the min/max value.
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func AdjustOOMScore(pid, score int) error {
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if score > OOMScoreAdjMax {
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score = OOMScoreAdjMax
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} else if score < OOMScoreAdjMin {
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score = OOMScoreAdjMin
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}
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return SetOOMScore(pid, score)
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}
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// SetOOMScore sets the oom score for the provided pid
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func SetOOMScore(pid, score int) error {
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if score > OOMScoreAdjMax || score < OOMScoreAdjMin {
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return fmt.Errorf("value out of range (%d): OOM score must be between %d and %d", score, OOMScoreAdjMin, OOMScoreAdjMax)
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}
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path := fmt.Sprintf("/proc/%d/oom_score_adj", pid)
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f, err := os.OpenFile(path, os.O_WRONLY, 0)
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if err != nil {
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return err
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}
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defer f.Close()
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if _, err = f.WriteString(strconv.Itoa(score)); err != nil {
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if os.IsPermission(err) && (!runningPrivileged() || userns.RunningInUserNS()) {
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return nil
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}
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return err
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}
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return nil
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}
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// GetOOMScoreAdj gets the oom score for a process. It returns 0 (zero) if either
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// no oom score is set, or a sore is set to 0.
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func GetOOMScoreAdj(pid int) (int, error) {
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path := fmt.Sprintf("/proc/%d/oom_score_adj", pid)
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data, err := ioutil.ReadFile(path)
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if err != nil {
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return 0, err
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}
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return strconv.Atoi(strings.TrimSpace(string(data)))
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}
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// runningPrivileged returns true if the effective user ID of the
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// calling process is 0
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func runningPrivileged() bool {
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return unix.Geteuid() == 0
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}
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