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.

makefiles/common.mk

@@ -11,6 +11,7 @@ KEEP ?= 0
 DEBUG ?= 0
 TRACE ?= 0
 PROFAPI ?= 0
+NVTX ?= 1
 
 NVCC = $(CUDA_HOME)/bin/nvcc
 
@@ -87,6 +88,10 @@ ifneq ($(TRACE), 0)
 CXXFLAGS  += -DENABLE_TRACE
 endif
 
+ifeq ($(NVTX), 0)
+CXXFLAGS  += -DNVTX_DISABLE
+endif
+
 ifneq ($(KEEP), 0)
 NVCUFLAGS += -keep
 endif

makefiles/version.mk

@@ -1,6 +1,6 @@
 ##### version
 NCCL_MAJOR   := 2
-NCCL_MINOR   := 7
-NCCL_PATCH   := 8
+NCCL_MINOR   := 8
+NCCL_PATCH   := 3
 NCCL_SUFFIX  :=
 PKG_REVISION := 1