func (b *Buffer) dontNeed(i, j uint64) error {
// Since i is rounded up to the nearest multiple of
// pageSize before the call, i > j is not an error.
if i > j {
return nil
}
return syscall.Madvise(b.data[i:j], syscall.MADV_DONTNEED)
}
func (buf *sharedBuffer) Advise(offset, length, advice int) error {
b := buf.Bytes()
err := checkOffsetLength(b, offset, length)
if err == nil {
err = syscall.Madvise(b[offset:offset+length], advice)
}
return os.NewSyscallError("shm: madvise", err)
}
func adviseRead(mem []byte) {
syscall.Madvise(mem, syscall.MADV_SEQUENTIAL|syscall.MADV_WILLNEED)
}
func adviseWrite(mem []byte) {
syscall.Madvise(mem, syscall.MADV_SEQUENTIAL)
}
// Give kernel hints about usage pattern.
func (m Mmap) Advise(advice Advice) error {
return syscall.Madvise(m, int(advice))
}