public void dropFileFromCache(File file) {
        try {
            dropFileFromCache(new FileInputStream(file).getFD());
        } catch (FileNotFoundException e) {
            logger.fine("No point in dropping a non-existing file from the buffer cache: " + e.getMessage());
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }
Will hint the OS that this is will not be accessed again and should hence be dropped from the buffer cache.
@param file File to drop from buffer cache
vespajlib/src/main/java/com/yahoo/io/NativeIO.java