Welcome to mirror list, hosted at ThFree Co, Russian Federation.

reduce.h « device « collectives « src - github.com/marian-nmt/nccl.git - Unnamed repository; edit this file 'description' to name the repository.
summaryrefslogtreecommitdiff
blob: 302d053a3f97b21a90d8ab397779a9161ab9d490 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
/*************************************************************************
 * Copyright (c) 2015-2018, NVIDIA CORPORATION. All rights reserved.
 *
 * See LICENSE.txt for license information
 ************************************************************************/

#include "core.h"
#include "primitives.h"
#include "collectives.h"

template<int UNROLL, class FUNC, typename T>
__device__ void ncclReduceRingKernel(struct CollectiveArgs* args) {
  const int tid = threadIdx.x;
  const int nthreads = blockDim.x - 1;
  const int bid = args->bid;
  struct ncclComm* comm = args->comm;
  struct ncclChannel* channel = comm->channels+blockIdx.x;
  struct ncclRing* ring = &channel->ring;
  const ssize_t size = args->N;
  const int nranks = comm->nRanks;
  const int stepSize = channel->buffSize / (sizeof(T)*NCCL_STEPS);
  const int chunkSize = stepSize * REDUCE_CHUNKSTEPS;
  const ssize_t loopSize = args->nChannels*(ssize_t)chunkSize;
  const int rank = ring->devUserRanks[0];
  const int prevRank = ring->devUserRanks[nranks-1];
  const int root = args->root;

  // Compute pointers
  const T * __restrict__ thisInput = (const T*)args->ThisInput;
  T * __restrict__ thisOutput = (T*)args->ThisOutput;

  ncclPrimitives<UNROLL, REDUCE_CHUNKSTEPS/REDUCE_SLICESTEPS, REDUCE_SLICESTEPS, T, 1, 1, FUNC>
    prims(tid, nthreads, &ring->prev, &ring->next, NULL, stepSize, channel, comm, args->opCount);

  for (ssize_t gridOffset = 0; gridOffset < size; gridOffset += loopSize) {
    int realChunkSize = min(chunkSize, DIVUP(size-gridOffset,args->nChannels));
    ALIGN_SIZE(realChunkSize, nthreads*sizeof(uint64_t)/sizeof(T));
    ssize_t offset = gridOffset + bid*realChunkSize;
    int nelem = min(realChunkSize, size-offset);
    if (prevRank == root) {
      prims.send(thisInput+offset, nelem);
    } else if (rank == root) {
      prims.recvReduceCopy(thisInput+offset, thisOutput+offset, nelem);
    } else {
      prims.recvReduceSend(thisInput+offset, nelem);
    }
  }
}

template<int UNROLL, class FUNC, typename T>
__device__ void ncclReduceTreeKernel(struct CollectiveArgs* args) { }

template<int UNUSED, class FUNC, typename T>
__device__ void ncclReduceRingLLKernel(struct CollectiveArgs* args) {
  const int tid = threadIdx.x;
  const int bid = args->bid;
  const int nthreads = args->nThreads;
  struct ncclComm* comm = args->comm;
  struct ncclChannel* channel = comm->channels+blockIdx.x;
  struct ncclRing* ring = &channel->ring;

  ncclLLPrimitives<T, FUNC, 1, 1> LLprims(tid, nthreads, &ring->prev, &ring->next, channel, comm, args->opCount);

  const ssize_t size = args->N;
  const int rank = comm->rank;
  const int nranks = comm->nRanks;
  const int prevRank = ring->devUserRanks[nranks-1];
  const int root = args->root;

  ssize_t chunkSize = NCCL_LL_SLICE_LINES * sizeof(uint64_t) / sizeof(T);
  const ssize_t loopSize = args->nChannels*chunkSize;

  // Compute pointers
  const T * __restrict__ thisInput = (const T*)args->ThisInput;
  T * __restrict__ thisOutput = (T*)args->ThisOutput;

  for (ssize_t gridOffset = 0; gridOffset < size; gridOffset += loopSize) {
    if (size-gridOffset < loopSize) {
      chunkSize = args->lastChunkSize;
    }
    ssize_t offset = gridOffset + bid*chunkSize;

    int nelem = min(chunkSize, size-offset);
    if (prevRank == root) {
      LLprims.send(thisInput+offset, nelem);
    } else if (rank == root) {
      LLprims.recvReduceCopy(thisInput+offset, thisOutput+offset, nelem);
    } else {
      LLprims.recvReduceSend(thisInput+offset, nelem);
    }
  }
}

template<int UNUSED, class FUNC, typename T>
__device__ void ncclReduceTreeLLKernel(struct CollectiveArgs* args) { }