linux-arm64 grabber.close() the memory do not release

as the title describe ,i use Pointer.formatBytes(Pointer.physicalBytes()) to mark the memory usage , when i call the grabber.close() and record.close(), in my macos,it release the memory ,but in linux-arm64 ,it can't

system: Linux version 4.9.201-tegra (rich@Vostro-5490) (gcc version 7.3.1 20180425 [linaro-7.3-2018.05 revision d29120a424ecfbc167ef90065c0eeb7f91977701] (Linaro GCC 7.3-2018.05) )

  FFmpegFrameGrabber grabber = new FFmpegFrameGrabber("rtsp://admin:LH123456@172.16.3.229:554/h264/ch41/main/av_stream");
        grabber.start();
        FFmpegFrameRecorder recorder = new FFmpegFrameRecorder("/data/ffmpeg/id-%03d.png", 1080, 720, 0);
        recorder.setFormat("image2");
        recorder.setOption("update", "0");
        recorder.start();
        try {
            Frame frame = null;
            int i = 0;
            for (; (frame = grabber.grabImage()) != null; ) {
                try {
                    recorder.record(frame);
                    i++;
                    if (i > 6) {
                        break;
                    }
                } catch (org.bytedeco.javacv.FrameRecorder.Exception e) {
                    e.printStackTrace();
                }
            }
        } finally {
            log.info("before：{}", Pointer.formatBytes(Pointer.physicalBytes()));
            grabber.close();
            recorder.close();
            log.info("after：{}", Pointer.formatBytes(Pointer.physicalBytes()));
        }