diff --git a/trunk/src/service/srs_service_st.cpp b/trunk/src/service/srs_service_st.cpp
index dc558829d..c9650379e 100644
--- a/trunk/src/service/srs_service_st.cpp
+++ b/trunk/src/service/srs_service_st.cpp
@@ -429,7 +429,7 @@ int srs_sendmmsg(srs_netfd_t stfd, struct mmsghdr *msgvec, unsigned int vlen, in
     return vlen;
 #else
     if (vlen == 1) {
-        #if 1
+        #if 0
             int r0 = srs_sendmsg(stfd, &msgvec->msg_hdr, flags, timeout);
             if (r0 < 0) {
                 return r0;
@@ -438,7 +438,7 @@ int srs_sendmmsg(srs_netfd_t stfd, struct mmsghdr *msgvec, unsigned int vlen, in
         #else
             int tolen = (int)msgvec->msg_hdr.msg_namelen;
             const struct sockaddr* to = (const struct sockaddr*)msgvec->msg_hdr.msg_name;
-            for (int i = 0; i < msgvec->msg_hdr.msg_iovlen; i++) {
+            for (int i = 0; i < (int)msgvec->msg_hdr.msg_iovlen; i++) {
                 iovec* iov = msgvec->msg_hdr.msg_iov + i;
                 int r0 = srs_sendto(stfd, (void*)iov->iov_base, (int)iov->iov_len, to, tolen, timeout);
                 if (r0 < 0) {