2.4.2-1

Add tree algorithms for allreduce to improve performance at scale.
Add ncclCommAbort() and ncclCommGetAsyncError() to properly handle
network errors and be permit recover.
Detect initial CPU affinity and no longer escape it.

src/include/socket.h

@@ -60,7 +60,9 @@ static inline int envSocketFamily(void) {
 }
 
 static int findInterfaces(const char* prefixList, char* names, union socketAddress *addrs, int sock_family, int maxIfNameSize, int maxIfs) {
+#ifdef ENABLE_TRACE
   char line[1024];
+#endif
   struct netIf userIfs[MAX_IFS];
   bool searchNot = prefixList && prefixList[0] == '^';
   int nUserIfs = parseStringList(prefixList, userIfs, MAX_IFS);
@@ -106,7 +108,6 @@ static int findInterfaces(const char* prefixList, char* names, union socketAddre
       // Store the IP address
       int salen = (family == AF_INET) ? sizeof(sockaddr_in) : sizeof(sockaddr_in6);
       memcpy(addrs+found, interface->ifa_addr, salen);
-      INFO(NCCL_INIT|NCCL_NET,"NET : Using interface %s:%s", interface->ifa_name, socketToString(interface->ifa_addr, line));
       found++;
     }
   }
@@ -336,8 +337,10 @@ static ncclResult_t createListenSocket(int *fd, union socketAddress *localAddr)
   TRACE(NCCL_INIT|NCCL_NET,"Listening on socket %s", socketToString(&localAddr->sa, line));
 #endif
 
-  /* Put the socket in listen mode */
-  SYSCHECK(listen(sockfd, 128), "listen");
+  /* Put the socket in listen mode
+   * NB: The backlog will be silently truncated to the value in /proc/sys/net/core/somaxconn
+   */
+  SYSCHECK(listen(sockfd, 16384), "listen");
   *fd = sockfd;
   return ncclSuccess;
 }