83 lines
		
	
	
		
			2.4 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
			
		
		
	
	
			83 lines
		
	
	
		
			2.4 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
| /*
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|    Copyright The containerd Authors.
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| 
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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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| 
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|        http://www.apache.org/licenses/LICENSE-2.0
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| 
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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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| 
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| package sys
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| 
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| import (
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| 	"fmt"
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| 	"os"
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| 	"strconv"
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| 	"strings"
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| 
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| 	"github.com/containerd/containerd/v2/pkg/userns"
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| 	"golang.org/x/sys/unix"
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| )
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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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| 
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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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| 
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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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| 
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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 := os.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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| 
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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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