gvisor.dev/gvisor@v0.0.0-20240520182842-f9d4d51c7e0f/test/benchmarks/tools/meminfo.go (about)

     1  // Copyright 2020 The gVisor Authors.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package tools
    16  
    17  import (
    18  	"fmt"
    19  	"regexp"
    20  	"strconv"
    21  	"testing"
    22  )
    23  
    24  // Meminfo wraps measurements of MemAvailable using /proc/meminfo.
    25  type Meminfo struct {
    26  }
    27  
    28  // MakeCmd returns a command for checking meminfo.
    29  func (*Meminfo) MakeCmd() (string, []string) {
    30  	return "cat", []string{"/proc/meminfo"}
    31  }
    32  
    33  // Report takes two reads of meminfo, parses them, and reports the difference
    34  // divided by b.N.
    35  func (*Meminfo) Report(b *testing.B, before, after string) {
    36  	b.Helper()
    37  
    38  	beforeVal, err := parseMemAvailable(before)
    39  	if err != nil {
    40  		b.Fatalf("could not parse before value %s: %v", before, err)
    41  	}
    42  
    43  	afterVal, err := parseMemAvailable(after)
    44  	if err != nil {
    45  		b.Fatalf("could not parse before value %s: %v", before, err)
    46  	}
    47  	val := 1024 * ((beforeVal - afterVal) / float64(b.N))
    48  	ReportCustomMetric(b, val, "average_container_size" /*metric name*/, "bytes" /*units*/)
    49  }
    50  
    51  var memInfoRE = regexp.MustCompile(`MemAvailable:\s*(\d+)\skB\n`)
    52  
    53  // parseMemAvailable grabs the MemAvailable number from /proc/meminfo.
    54  func parseMemAvailable(data string) (float64, error) {
    55  	match := memInfoRE.FindStringSubmatch(data)
    56  	if len(match) < 2 {
    57  		return 0, fmt.Errorf("couldn't find MemAvailable in %s", data)
    58  	}
    59  	return strconv.ParseFloat(match[1], 64)
    60  }