2.8.3-1

Optimization for Tree allreduce on A100.
Improve aggregation performance.
Use shared buffers for inter-node send/recv.
Add NVTX profiling hooks.
Accelerate alltoall connections by merging communication for all
channels.
Add support for one hop communication through NVLink, for faster
send/recv communication on cubemesh topologies like DGX-1.
Improve alltoall scheduling to better balance intra/inter node
communication.
Increase send/recv parallelism by 8x, each warp sending or
receiving to a different peer.
Net: move to v4.
Net: make flush operation asynchronous to accelerate alltoall.
Net: define maximum number of requests.
Fix hang when using LL128 protocol after 2^31 steps.
Fix #379 : topology injection failing when using less GPUs than
described in the XML.
Fix #394 : protocol mismatch causing hangs or crashes when using
one GPU per node.

src/include/trees.h

@@ -1,5 +1,5 @@
 /*************************************************************************
- * Copyright (c) 2015-2019, NVIDIA CORPORATION. All rights reserved.
+ * Copyright (c) 2015-2020, NVIDIA CORPORATION. All rights reserved.
  *
  * See LICENSE.txt for license information
  ************************************************************************/
@@ -7,7 +7,7 @@
 #ifndef NCCL_TREES_H_
 #define NCCL_TREES_H_
 
-ncclResult_t ncclGetBtree(int nranks, int rank, int* u0, int* d1, int* d0);
-ncclResult_t ncclGetDtree(int nranks, int rank, int* u0, int* d0_0, int* d0_1, int* u1, int* d1_0, int* d1_1);
+ncclResult_t ncclGetBtree(int nranks, int rank, int* u0, int* d1, int* d0, int* parentChildType);
+ncclResult_t ncclGetDtree(int nranks, int rank, int* u0, int* d0_0, int* d0_1, int* parentChildType0, int* u1, int* d1_0, int* d1_1, int* parentChildType1);
 
 #endif