Hi： I have some confusion about sending reply to client。In the process of sending the response，fouction svc_ioq_flushv() would be called. Here, use the writev() system call to send reply via sockfd. I think we're using non-blocking socket here, but comment is "/* blocking write */" and the transport is finish when return < 0. Why? result = writev(xprt->xp_fd, wiov, iw); remaining -= result; if (result == fbytes) { wiov += iw - 1; iw = 0; continue; } if (unlikely(result < 0)) { __warnx(TIRPC_DEBUG_FLAG_ERROR, "%s() writev failed (%d)\n", __func__, errno); cfconn_set_dead(xprt); break; } I think when the return code is less than 0, we should judge whether the error code is EAGAIN.