CAMLparam3(fd_in, fd_out, len);
long ret;
ret = syscall(SPLICE_SYSCALL, Int_val(fd_in), NULL, Int_val(fd_out),NULL, Int_val(len), SPLICE_F_NONBLOCK);
CAMLparam3(fd_in, fd_out, len);
long ret;
ret = syscall(SPLICE_SYSCALL, Int_val(fd_in), NULL, Int_val(fd_out),NULL, Int_val(len), SPLICE_F_NONBLOCK);