github.com/demonoid81/containerd@v1.3.4/sys/oom_unix.go (about)

     1  // +build !windows
     2  
     3  /*
     4     Copyright The containerd Authors.
     5  
     6     Licensed under the Apache License, Version 2.0 (the "License");
     7     you may not use this file except in compliance with the License.
     8     You may obtain a copy of the License at
     9  
    10         http://www.apache.org/licenses/LICENSE-2.0
    11  
    12     Unless required by applicable law or agreed to in writing, software
    13     distributed under the License is distributed on an "AS IS" BASIS,
    14     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    15     See the License for the specific language governing permissions and
    16     limitations under the License.
    17  */
    18  
    19  package sys
    20  
    21  import (
    22  	"fmt"
    23  	"io/ioutil"
    24  	"os"
    25  	"strconv"
    26  	"strings"
    27  
    28  	"github.com/opencontainers/runc/libcontainer/system"
    29  )
    30  
    31  // OOMScoreMaxKillable is the maximum score keeping the process killable by the oom killer
    32  const OOMScoreMaxKillable = -999
    33  
    34  // SetOOMScore sets the oom score for the provided pid
    35  func SetOOMScore(pid, score int) error {
    36  	path := fmt.Sprintf("/proc/%d/oom_score_adj", pid)
    37  	f, err := os.OpenFile(path, os.O_WRONLY, 0)
    38  	if err != nil {
    39  		return err
    40  	}
    41  	defer f.Close()
    42  	if _, err = f.WriteString(strconv.Itoa(score)); err != nil {
    43  		if os.IsPermission(err) && (system.RunningInUserNS() || RunningUnprivileged()) {
    44  			return nil
    45  		}
    46  		return err
    47  	}
    48  	return nil
    49  }
    50  
    51  // GetOOMScoreAdj gets the oom score for a process
    52  func GetOOMScoreAdj(pid int) (int, error) {
    53  	path := fmt.Sprintf("/proc/%d/oom_score_adj", pid)
    54  	data, err := ioutil.ReadFile(path)
    55  	if err != nil {
    56  		return 0, err
    57  	}
    58  	return strconv.Atoi(strings.TrimSpace(string(data)))
    59  }