invalid argument

[lysShub]

//go:build linux
// +build linux

package main

import (
    "bytes"
    "fmt"
    "io"
    _ "net/http/pprof"
    "os"

    "github.com/edsrzf/mmap-go"
)

func main() {
    f, err := os.Open("/proc/net/tcp")
    if err != nil {
        panic(err)
    }

    b1, err := io.ReadAll(f)
    if err != nil {
        panic(err)
    }
    fmt.Println("normal", bytes.Count(b1, []byte{'\n'}))

    b2, err := mmap.Map(f, mmap.RDONLY, 0)
    if err != nil {
        panic(err)
    }

    fmt.Println("mmap", bytes.Count(b2, []byte{'\n'}))
}

output:

normal 7
panic: invalid argument

goroutine 1 [running]:
main.main()
        /root/atest/main.go:27 +0x18d
exit status 2