Files
rocm-systems/src/graph/tuning.cc
T
2025-04-18 17:09:50 -04:00

720 γραμμές
40 KiB
C++

/*************************************************************************
* Copyright (c) 2016-2022, NVIDIA CORPORATION. All rights reserved.
* Modifications Copyright (c) 2019-2022 Advanced Micro Devices, Inc. All rights reserved.
*
* See LICENSE.txt for license information
************************************************************************/
#include "core.h"
#include "device.h"
#include "comm.h"
#include "topo.h"
NCCL_PARAM(Nthreads, "NTHREADS", -2);
NCCL_PARAM(Ll128Nthreads, "LL128_NTHREADS", -2);
static int getNthreads(const char* name, int env, int min, int max, int def, int WarpSize) {
int nt = env;
if (nt > 0) {
if (nt % WarpSize != 0) {
WARN("Invalid %s %d (must be a multiple of %d)", name, nt, WarpSize);
nt = max;
} else if (nt > max) {
WARN("Invalid %s %d (maximum %d).", name, nt, max);
nt = max;
} else if (nt < min) {
WARN("Invalid %s %d (minimum %d).", name, nt, min);
nt = min;
}
} else {
nt = def;
}
return nt;
}
ncclResult_t parseList(const char* str, const char* elems[], int nelems, int* list) {
int def, set;
if (str[0] == '^') {
def = 1; set = 0; str++;
} else {
def = 0; set = 1;
}
for (int i=0; i<nelems; i++) list[i] = def;
char* tokStr = strdup(str);
char* tmpStr;
char* token = strtok_r(tokStr, ",", &tmpStr);
while (token) {
for (int i=0; i<nelems; i++)
if (strcasecmp(token, elems[i]) == 0) list[i] = set;
token = strtok_r(NULL, ",", &tmpStr);
}
free(tokStr);
return ncclSuccess;
}
// Latencies in us, Bandwidths in GB/s
// Tree { LL, LL128, Simple } , Ring { LL, LL128, Simple }
static const float baseLat [NCCL_NUM_ALGORITHMS][NCCL_NUM_PROTOCOLS] = {
{ 12.0, 12.0, 17.0 }, { 12.0, 12.0, 17.0 }, // Tree, Ring
{ 12.0, 12.0, 17.0 }, { 12.0, 12.0, 17.0 }, // Collnet Direct, Chain
{ 0, 0, 0 }, { 0, 0, 0 }}; // NVLS, NVLS Tree
// NVLink, PCI, Network
#define NCCL_HW_NVLINK 0
#define NCCL_HW_PCI 1
#define NCCL_HW_NET 2
struct tuningModel {
float hwLat [3][NCCL_NUM_ALGORITHMS][NCCL_NUM_PROTOCOLS];
float bwRatio [2][NCCL_NUM_ALGORITHMS][NCCL_NUM_PROTOCOLS];
float treeCorrectionFactor[NCCL_NUM_PROTOCOLS][27];
float ringCorrectionFactor[NCCL_NUM_PROTOCOLS][27];
uint64_t llProtoRanges[RCCL_TUNABLE_COLLS][NCCL_NUM_PROTOCOLS - 1][RCCL_PROTOCOL_ENTRY_SIZE];
};
static struct tuningModel tuning_model_0 {
.hwLat = {
/* NVLINK */
{ /* Tree (LL/LL128/Simple)*/ { 0.8, 1.4, 2.5 }, /* Ring (LL/LL128/Simple)*/ { 0.8, 2.2, 3.6 }, /* CollNetDirect (Simple)*/ { 0.0, 0.0, 0.8 }, /* CollNetChain (Simple)*/ { 0.0, 0.0, 1.4 }, /* NVLS */ { 0, 0, 0 }, /* NVLS Tree */ { 0, 0, 0 } },
/* PCI */
{ /* Tree (LL/LL128/Simple)*/ { 2.2, 2.2, 5.7 }, /* Ring (LL/LL128/Simple)*/ { 2.2, 2.2, 5.7 }, /* CollNetDirect (Simple)*/ { 0.0, 0.0, 5.7 }, /* CollNetChain (Simple)*/ { 0.0, 0.0, 5.7 }, /* NVLS */ { 0, 0, 0 }, /* NVLS Tree */ { 0, 0, 0 } },
/* NET */
{ /* Tree (LL/LL128/Simple)*/ { 11.8, 18.2, 20.8 }, /* Ring (LL/LL128/Simple)*/ { 9.5, 19.8, 15.1 }, /* CollNetDirect (Simple)*/ { 0.0, 0.0, 11.8 }, /* CollNetChain (Simple)*/ { 0.0, 0.0, 18.2 }, /* NVLS */ { 0, 0, 0 }, /* NVLS Tree */ { 0, 0, 0 } },
},
.bwRatio = {
/* 2 nodes */
{ /* Tree (LL/LL128/Simple)*/ { 0.04, 0.22, 0.91 }, /* Ring (LL/LL128/Simple)*/ { 0.04, 0.34, 1.00 }, /* CollNetDirect (Simple)*/ { 0.00, 0.00, 1.00 }, /* CollNetChain (Simple)*/ { 0.00, 0.00, 1.00 }, /* NVLS */ { 0, 0, 0 }, /* NVLS Tree */ { 0, 0, 0 } },
/* more than 2 nodes */
{ /* Tree (LL/LL128/Simple)*/ { 0.04, 0.22, 0.95 }, /* Ring (LL/LL128/Simple)*/ { 0.04, 0.34, 1.00 }, /* CollNetDirect (Simple)*/ { 0.00, 0.00, 1.00 }, /* CollNetChain (Simple)*/ { 0.00, 0.00, 1.00 }, /* NVLS */ { 0, 0, 0 }, /* NVLS Tree */ { 0, 0, 0 } },
},
.treeCorrectionFactor = {
{ 0.1, 0.2, 0.1, 0.1, 0.9, 0.3, 0.4, 0.1, 0.2, 0.4, 0.2, 0.1, 0.3, 0.3, 0.2, 0.2, 0.2, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, },
{ 0.1, 0.3, 1.0, 0.1, 0.5, 1.0, 0.9, 1.0, 1.0, 1.0, 0.3, 0.1, 0.4, 0.5, 0.5, 0.4, 0.4, 0.3, 0.3, 0.2, 0.2, 0.2, 0.2, 0.2, 0.2, 0.2, 0.2, },
{ 0.2, 1.0, 0.1, 0.1, 0.7, 0.2, 0.4, 0.1, 0.1, 0.3, 0.4, 0.3, 0.6, 0.8, 1.0, 1.0, 1.0, 1.0, 0.9, 0.8, 0.8, 0.8, 0.8, 0.8, 0.9, 0.9, 0.9, },
},
.ringCorrectionFactor = {
{ 0.1, 0.1, 0.1, 0.1, 0.1, 0.2, 0.4, 0.2, 0.3, 0.5, 0.3, 0.1, 0.5, 0.5, 0.3, 0.2, 0.2, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, },
{ 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.3, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 0.8, 0.7, 0.5, 0.4, 0.4, 0.3, 0.3, 0.3, 0.3, 0.3, 0.3, },
{ 1.0, 0.8, 0.2, 1.0, 1.0, 0.3, 1.0, 0.1, 0.1, 0.2, 0.2, 0.1, 0.5, 1.0, 0.8, 0.8, 1.0, 0.9, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, },
},
.llProtoRanges = {RCCL_LL_LIMITS_UNDEFINED},
};
static struct tuningModel tuning_model_1 {
.hwLat =
{ /* NVLINK */
{ /* Tree (LL/LL128/Simple)*/ { 1.5, 1.5, 4.5 }, /* Ring (LL/LL128/Simple)*/ { 1.5, 1.5, 4.5 }, /* CollNetDirect (Simple)*/ { 0.0, 0.0, 4.5 }, /* CollNetChain (Simple)*/ { 0.0, 0.0, 4.5 }, /* NVLS */ { 0, 0, 0 }, /* NVLS Tree */ { 0, 0, 0 } },
/* PCI */
{ /* Tree (LL/LL128/Simple)*/ { 2.2, 2.2, 5.7 }, /* Ring (LL/LL128/Simple)*/ { 2.2, 2.2, 5.7 }, /* CollNetDirect (Simple)*/ { 0.0, 0.0, 5.7 }, /* CollNetChain (Simple)*/ { 0.0, 0.0, 5.7 }, /* NVLS */ { 0, 0, 0 }, /* NVLS Tree */ { 0, 0, 0 } },
/* NET */
{ /* Tree (LL/LL128/Simple)*/ { 33.0, 33.0, 15.8 }, /* Ring (LL/LL128/Simple)*/ { 5.1, 5.1, 68.8 }, /* CollNetDirect (Simple)*/ { 0.0, 0.0, 15.8 }, /* CollNetChain (Simple)*/ { 0.0, 0.0, 15.8 }, /* NVLS */ { 0, 0, 0 }, /* NVLS Tree */ { 0, 0, 0 } },
},
.bwRatio =
{ /* 2 nodes */
{ /* Tree (LL/LL128/Simple)*/ { 0.12, 1.00, 0.99 }, /* Ring (LL/LL128/Simple)*/ { 0.12, 1.00, 1.00 }, /* CollNetDirect (Simple)*/ { 0.00, 0.00, 1.00 }, /* CollNetChain (Simple)*/ { 0.00, 0.00, 1.00 }, /* NVLS */ { 0, 0, 0 }, /* NVLS Tree */ { 0, 0, 0 } },
/* more than 2 nodes */
{ /* Tree (LL/LL128/Simple)*/ { 0.15, 1.00, 0.42 }, /* Ring (LL/LL128/Simple)*/ { 0.20, 1.00, 1.00 }, /* CollNetDirect (Simple)*/ { 0.00, 0.00, 1.00 }, /* CollNetChain (Simple)*/ { 0.00, 0.00, 1.00 }, /* NVLS */ { 0, 0, 0 }, /* NVLS Tree */ { 0, 0, 0 } },
},
.treeCorrectionFactor = {
{ 0.5, 0.4, 0.7, 0.6, 1.0, 1.0, 0.5, 0.4, 0.1, 0.5, 0.4, 0.6, 1.0, 1.0, 1.0, 1.0, 1.0, 0.8, 0.6, 0.5, 0.4, 0.4, 0.3, 0.2, 0.1, 0.1, 0.1, },
{ 0.5, 0.4, 0.7, 0.6, 1.0, 1.0, 0.5, 0.4, 0.1, 0.5, 0.4, 0.6, 1.0, 1.0, 1.0, 1.0, 1.0, 0.8, 0.6, 0.5, 0.4, 0.4, 0.3, 0.2, 0.1, 0.1, 0.1, },
{ 0.1, 0.1, 0.1, 0.1, 0.1, 0.3, 0.4, 0.5, 0.1, 0.6, 1.0, 1.0, 1.0, 0.6, 0.5, 0.7, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 0.7, 0.5, 0.3, 0.3, },
},
.ringCorrectionFactor = {
{ 1.0, 0.5, 1.0, 1.0, 0.6, 0.7, 1.0, 1.0, 0.2, 1.0, 0.9, 0.7, 1.0, 1.0, 1.0, 0.9, 0.9, 0.8, 0.8, 0.7, 0.6, 0.5, 0.5, 0.3, 0.2, 0.1, 0.1, },
{ 1.0, 0.5, 1.0, 1.0, 0.6, 0.7, 1.0, 1.0, 0.2, 1.0, 0.9, 0.7, 1.0, 1.0, 1.0, 0.9, 0.9, 0.8, 0.8, 0.7, 0.6, 0.5, 0.5, 0.3, 0.2, 0.1, 0.1, },
{ 0.3, 1.0, 0.3, 0.1, 0.1, 0.1, 0.3, 0.7, 1.0, 0.2, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.2, 0.3, 0.5, 0.9, 1.0, 1.0, 1.0, 1.0, },
},
.llProtoRanges = {RCCL_LL_LIMITS_UNDEFINED},
};
static struct tuningModel tuning_model_2 {
.hwLat = {
/* NVLINK */
{ /* Tree (LL/LL128/Simple)*/ { 1.5, 1.5, 4.5 }, /* Ring (LL/LL128/Simple)*/ { 1.5, 1.5, 4.5 }, /* CollNetDirect (Simple)*/ { 0.0, 0.0, 4.5 }, /* CollNetChain (Simple)*/ { 0.0, 0.0, 4.5 }, /* NVLS */ { 0, 0, 0 }, /* NVLS Tree */ { 0, 0, 0 } },
/* PCI */
{ /* Tree (LL/LL128/Simple)*/ { 2.2, 2.2, 5.7 }, /* Ring (LL/LL128/Simple)*/ { 2.2, 2.2, 5.7 }, /* CollNetDirect (Simple)*/ { 0.0, 0.0, 5.7 }, /* CollNetChain (Simple)*/ { 0.0, 0.0, 5.7 }, /* NVLS */ { 0, 0, 0 }, /* NVLS Tree */ { 0, 0, 0 } },
/* NET */
{ /* Tree (LL/LL128/Simple)*/ { 27.9, 27.9, 15.8 }, /* Ring (LL/LL128/Simple)*/ { 12.1, 12.1, 68.8 }, /* CollNetDirect (Simple)*/ { 0.0, 0.0, 15.8 }, /* CollNetChain (Simple)*/ { 0.0, 0.0, 15.8 }, /* NVLS */ { 0, 0, 0 }, /* NVLS Tree */ { 0, 0, 0 } },
},
.bwRatio = {
/* 2 nodes */
{ /* Tree (LL/LL128/Simple)*/ { 0.07, 1.00, 0.99 }, /* Ring (LL/LL128/Simple)*/ { 0.08, 1.00, 1.00 }, /* CollNetDirect (Simple)*/ { 0.00, 0.00, 1.00 }, /* CollNetChain (Simple)*/ { 0.00, 0.00, 1.00 }, /* NVLS */ { 0, 0, 0 }, /* NVLS Tree */ { 0, 0, 0 } },
/* more than 2 nodes */
{ /* Tree (LL/LL128/Simple)*/ { 0.07, 1.00, 0.42 }, /* Ring (LL/LL128/Simple)*/ { 0.08, 1.00, 1.00 }, /* CollNetDirect (Simple)*/ { 0.00, 0.00, 1.00 }, /* CollNetChain (Simple)*/ { 0.00, 0.00, 1.00 }, /* NVLS */ { 0, 0, 0 }, /* NVLS Tree */ { 0, 0, 0 } },
},
.treeCorrectionFactor = {
{ 0.1, 0.4, 0.3, 0.3, 0.2, 0.4, 0.5, 0.1, 0.1, 0.6, 0.7, 0.7, 0.8, 1.0, 0.9, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, 0.2, 0.2, 0.2, 0.2, 0.2, 0.2, },
{ 0.1, 0.4, 0.3, 0.3, 0.2, 0.4, 0.5, 0.1, 0.1, 0.6, 0.7, 0.7, 0.8, 1.0, 0.9, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, 0.2, 0.2, 0.2, 0.2, 0.2, 0.2, },
{ 1.0, 0.1, 0.1, 0.1, 0.1, 0.2, 0.3, 0.5, 0.1, 0.6, 0.9, 0.8, 0.7, 0.9, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 0.7, 0.9, 0.9, 1.0, 1.0, 1.0, },
},
.ringCorrectionFactor = {
{ 0.1, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 0.4, 1.0, 1.0, 1.0, 1.0, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, 0.2, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, },
{ 0.1, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 0.4, 1.0, 1.0, 1.0, 1.0, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, 0.2, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, },
{ 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 1.0, 0.2, 0.2, 0.1, 0.1, 0.1, 0.1, 0.1, 0.2, 0.4, 0.5, 0.6, 0.9, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, },
},
.llProtoRanges = {RCCL_LL_LIMITS_UNDEFINED},
};
static struct tuningModel tuning_model_3 {
.hwLat = {
/* NVLINK */
{ /* Tree (LL/LL128/Simple)*/ { 0.8, 0.0, 2.5 }, /* Ring (LL/LL128/Simple)*/ { 0.8, 0.0, 3.6 }, /* CollNetDirect (Simple)*/ { 0.0, 0.0, 0.8 }, /* CollNetChain (Simple)*/ { 0.0, 0.0, 0.0 }, /* NVLS */ { 0, 0, 0 }, /* NVLS Tree */ { 0, 0, 0 } },
/* PCI */
{ /* Tree (LL/LL128/Simple)*/ { 2.2, 2.2, 5.7 }, /* Ring (LL/LL128/Simple)*/ { 2.2, 2.2, 5.7 }, /* CollNetDirect (Simple)*/ { 0.0, 0.0, 5.7 }, /* CollNetChain (Simple)*/ { 0.0, 0.0, 5.7 }, /* NVLS */ { 0, 0, 0 }, /* NVLS Tree */ { 0, 0, 0 } },
/* NET */
{ /* Tree (LL/LL128/Simple)*/ { 12.5, 0.0, 22.4 }, /* Ring (LL/LL128/Simple)*/ { 9.5, 0.0, 19.8 }, /* CollNetDirect (Simple)*/ { 0.0, 0.0, 12.5 }, /* CollNetChain (Simple)*/ { 0.0, 0.0, 0.0 }, /* NVLS */ { 0, 0, 0 }, /* NVLS Tree */ { 0, 0, 0 } },
},
.bwRatio = {
/* 2 nodes */
{ /* Tree (LL/LL128/Simple)*/ { 0.20, 0.00, 1.75 }, /* Ring (LL/LL128/Simple)*/ { 0.20, 0.00, 1.00 }, /* CollNetDirect (Simple)*/ { 0.00, 0.00, 1.00 }, /* CollNetChain (Simple)*/ { 0.00, 0.00, 1.00 }, /* NVLS */ { 0, 0, 0 }, /* NVLS Tree */ { 0, 0, 0 } },
/* more than 2 nodes */
{ /* Tree (LL/LL128/Simple)*/ { 0.20, 0.00, 0.96 }, /* Ring (LL/LL128/Simple)*/ { 0.20, 0.00, 1.00 }, /* CollNetDirect (Simple)*/ { 0.00, 0.00, 1.00 }, /* CollNetChain (Simple)*/ { 0.00, 0.00, 1.00 }, /* NVLS */ { 0, 0, 0 }, /* NVLS Tree */ { 0, 0, 0 } },
},
.treeCorrectionFactor = {
{ 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 1.0, 1.0, 0.2, 1.0, 0.9, 1.0, 0.6, 0.4, 0.6, 0.4, 0.3, 0.3, 0.3, 0.3, 0.3, 0.2, 0.2, 0.2, 0.2, 0.2, 0.2, },
{ 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, },
{ 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 0.1, 0.1, 0.1, 0.2, 1.0, 0.8, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 0.8, 0.7, 0.8, 0.9, 0.7, 0.7, },
},
.ringCorrectionFactor = {
{ 0.1, 0.1, 0.1, 0.1, 0.1, 0.3, 0.1, 0.2, 0.1, 0.4, 0.4, 0.2, 0.2, 0.3, 0.7, 0.5, 0.4, 0.3, 0.3, 0.3, 0.3, 0.2, 0.2, 0.2, 0.2, 0.2, 0.2, },
{ 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, },
{ 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.5, 1.0, 0.1, 0.3, 0.1, 0.1, 0.1, 0.2, 0.2, 0.2, 0.3, 0.4, 0.7, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, },
},
.llProtoRanges = {RCCL_LL_LIMITS_UNDEFINED},
};
static struct tuningModel tuning_model_4 {
.hwLat = {
/* NVLINK */
{ /* Tree (LL/LL128/Simple)*/ { 0.8, 1.4, 2.5 }, /* Ring (LL/LL128/Simple)*/ { 0.8, 2.2, 3.6 }, /* CollNetDirect (Simple)*/ { 0.8, 1.4, 2.5 }, /* CollNetChain (Simple)*/ { 0.8, 1.4, 2.5 }, /* NVLS */ { 0, 0, 0 }, /* NVLS Tree */ { 0, 0, 0 } },
/* PCI */
{ /* Tree (LL/LL128/Simple)*/ { 2.2, 2.2, 5.7 }, /* Ring (LL/LL128/Simple)*/ { 2.2, 2.2, 5.7 }, /* CollNetDirect (Simple)*/ { 0.0, 0.0, 5.7 }, /* CollNetChain (Simple)*/ { 0.0, 0.0, 5.7 }, /* NVLS */ { 0, 0, 0 }, /* NVLS Tree */ { 0, 0, 0 } },
/* NET */
{ /* Tree (LL/LL128/Simple)*/ { 32.2, 34.4, 47.6 }, /* Ring (LL/LL128/Simple)*/ { 35.4, 87.8, 209.2 }, /* CollNetDirect (Simple)*/ { 0.0, 0.0, 47.6 }, /* CollNetChain (Simple)*/ { 0.0, 0.0, 47.6 }, /* NVLS */ { 0, 0, 0 }, /* NVLS Tree */ { 0, 0, 0 } },
},
.bwRatio = {
/* 2 nodes */
{ /* Tree (LL/LL128/Simple)*/ { 0.16, 1.09, 1.61 }, /* Ring (LL/LL128/Simple)*/ { 0.15, 0.41, 1.00 }, /* CollNetDirect (Simple)*/ { 0.00, 0.00, 1.00 }, /* CollNetChain (Simple)*/ { 0.00, 0.00, 1.00 }, /* NVLS */ { 0, 0, 0 }, /* NVLS Tree */ { 0, 0, 0 } },
/* more than 2 nodes */
{ /* Tree (LL/LL128/Simple)*/ { 0.16, 1.09, 1.08 }, /* Ring (LL/LL128/Simple)*/ { 0.15, 0.41, 1.00 }, /* CollNetDirect (Simple)*/ { 0.00, 0.00, 1.00 }, /* CollNetChain (Simple)*/ { 0.00, 0.00, 1.00 }, /* NVLS */ { 0, 0, 0 }, /* NVLS Tree */ { 0, 0, 0 } },
},
.treeCorrectionFactor = {
{ 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 1.0, 0.1, 0.1, 0.2, 0.4, 0.6, 0.5, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, },
{ 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.2, 0.1, 0.1, 0.2, 1.0, 0.5, 0.2, 0.2, 0.2, 0.2, 0.2, 0.2, 0.2, 0.2, 0.2, 0.2, 0.2, 0.2, },
{ 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 0.8, 0.4, 0.3, 0.3, 0.1, 0.1, 1.0, 1.0, 0.7, 0.5, 0.6, 0.5, 0.6, 0.6, 0.5, 0.6, 0.6, 0.6, 0.7, },
},
.ringCorrectionFactor = {
{ 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.2, 0.2, 0.1, 0.3, 0.1, 0.1, 0.1, 0.2, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, },
{ 0.4, 0.5, 0.5, 0.4, 0.4, 0.4, 0.4, 0.2, 0.2, 0.1, 0.3, 1.0, 1.0, 0.7, 0.8, 0.5, 1.0, 1.0, 1.0, 1.0, 1.0, 0.9, 0.8, 0.5, 0.4, 0.3, 0.3, },
{ 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 1.0, 1.0, 0.8, 0.5, 0.1, 0.7, 0.2, 0.4, 0.4, 0.6, 0.7, 0.9, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, },
},
.llProtoRanges = {RCCL_LL_LIMITS_UNDEFINED},
};
static struct tuningModel tuning_model_5 {
.hwLat = {
/* NVLINK */
{ /* Tree (LL/LL128/Simple)*/ { 0.9, 0.9, 2.3 }, /* Ring (LL/LL128/Simple)*/ { 0.8, 0.8, 2.1 }, /* CollNetDirect (Simple)*/ { 0.0, 0.0, 0.9 }, /* CollNetChain (Simple)*/ { 0.0, 0.0, 0.0 }, /* NVLS */ { 0, 0, 0 }, /* NVLS Tree */ { 0, 0, 0 } },
/* PCI */
{ /* Tree (LL/LL128/Simple)*/ { 2.2, 2.2, 5.7 }, /* Ring (LL/LL128/Simple)*/ { 2.2, 2.2, 5.7 }, /* CollNetDirect (Simple)*/ { 0.0, 0.0, 5.7 }, /* CollNetChain (Simple)*/ { 0.0, 0.0, 5.7 }, /* NVLS */ { 0, 0, 0 }, /* NVLS Tree */ { 0, 0, 0 } },
/* NET */
{ /* Tree (LL/LL128/Simple)*/ { 10.5, 10.5, 25.0 }, /* Ring (LL/LL128/Simple)*/ { 9.5, 9.5, 320.0 }, /* CollNetDirect (Simple)*/ { 0.0, 0.0, 10.5 }, /* CollNetChain (Simple)*/ { 0.0, 0.0, 0.0 }, /* NVLS */ { 0, 0, 0 }, /* NVLS Tree */ { 0, 0, 0 } },
},
.bwRatio = {
/* 2 nodes */
{ /* Tree (LL/LL128/Simple)*/ { 0.06, 0.06, 0.11 }, /* Ring (LL/LL128/Simple)*/ { 0.08, 0.08, 1.00 }, /* CollNetDirect (Simple)*/ { 0.00, 0.00, 1.00 }, /* CollNetChain (Simple)*/ { 0.00, 0.00, 1.00 }, /* NVLS */ { 0, 0, 0 }, /* NVLS Tree */ { 0, 0, 0 } },
/* more than 2 nodes */
{ /* Tree (LL/LL128/Simple)*/ { 0.06, 0.06, 0.59 }, /* Ring (LL/LL128/Simple)*/ { 0.08, 0.08, 1.00 }, /* CollNetDirect (Simple)*/ { 0.00, 0.00, 1.00 }, /* CollNetChain (Simple)*/ { 0.00, 0.00, 1.00 }, /* NVLS */ { 0, 0, 0 }, /* NVLS Tree */ { 0, 0, 0 } },
},
.treeCorrectionFactor = {
{ 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 1.0, 1.0, 1.0, 1.0, 1.0, 0.6, 1.0, 0.9, 1.0, 1.0, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, },
{ 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 1.0, 1.0, 1.0, 1.0, 1.0, 0.6, 1.0, 0.9, 1.0, 1.0, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, },
{ 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.7, 1.0, 1.0, 1.0, 1.0, 1.0, 0.7, 0.7, 0.5, 0.6, 0.6, 0.6, },
},
.ringCorrectionFactor = {
{ 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 1.0, 0.2, 1.0, 0.4, 0.4, 0.1, 0.2, 0.2, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, },
{ 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 1.0, 0.2, 1.0, 0.4, 0.4, 0.1, 0.2, 0.2, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, },
{ 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 1.0, 0.8, 1.0, 1.0, 1.0, },
},
// Follow order in RcclTunableColls
.llProtoRanges = {
/*ReduceScatter*/
{/*LL (min/max/factor)*/ {0, 655360, 1}, /*LL64/128 (min/max/factor)*/ {131072, 3211264, 1}},
/*AllGather*/
{/*LL (min/max/factor)*/ {0, 98304, 1}, /*LL64/128 (min/max/factor)*/ {98304, 5046272, 1}},
/*AllReduce*/
{/*LL (min/max/factor)*/ {0, 1048576, 1},/*LL64/128 (min/max/factor)*/ {1048576, 9437184, 3145728}},
},
};
static struct tuningModel rcclTuningModel[] = {
tuning_model_0,
tuning_model_1,
tuning_model_2,
tuning_model_3,
tuning_model_4,
tuning_model_5,
};
/* Array indexes used below */
#define VOLTA_COMPCAP_IDX 0
#define AMPERE_COMPCAP_IDX 1
#define HOPPER_COMPCAP_IDX 2
// LL128 max BW per channel
static const double llMaxBws[3][3] = {
/* Volta-N1/Intel-N2/Intel-N4) */ {39.0, 39.0, 20.4},
/* Ampere-N1/AMD-N2/AMD-N4) */ {87.7, 22.5 /*avg of ring & tree*/, 19.0},
/* Hopper-N1/AMD-N2/AMD-N4) */ {141.0, 45.0 /*avg of ring & tree*/, 35.0}
};
static const double perChMaxRingLL128Bws[3][3] = {
/* Volta (N1/N2/N4) */ {20.0, 20.0, 20.0},
/* Ampere (N1/N2/N4) */ {20.0, 20.0, 20.0},
/* Hopper (N1/N2/N4) */ {36.7, 36.7, 36.7},
};
static const double perChMaxTreeLL128Bws[3][3] = {
/* Volta (N1/N2/N4) */ {20.0, 20.0, 20.0},
/* Ampere (N1/N2/N4) */ {20.0, 20.0, 20.0},
/* Hopper (N1/N2/N4) */ {36.7, 36.7, 29.0},
};
static const double perChMaxTreeBws[3][3] = {
/* Volta (N1/N2/N4) */ {26.5, 18.5, 10.0},
/* Ampere (N1/N2/N4) */ {24.0, 23.6, 17.8},
/* Hopper (N1/N2/N4) */ {38.7, 41.4, 36.0},
};
NCCL_PARAM(PatEnable, "PAT_ENABLE", 2);
static int ncclPatEnable(struct ncclComm* comm) {
int patEnable = ncclParamPatEnable();
if (patEnable != 2) return patEnable;
if (comm->nNodes != comm->nRanks) return 0; // PAT only supports 1 GPU per node
if (comm->netDeviceType != NCCL_NET_DEVICE_HOST) return 0; // PAT doesn't support net device offload
return 1;
}
// Network post overhead in ns (1000 = 1 us)
NCCL_PARAM(NetOverhead, "NET_OVERHEAD", -2);
static float getNetOverhead(struct ncclComm* comm) {
if (ncclParamNetOverhead() != -2) return ncclParamNetOverhead() * .001;
if (comm->cpuArch == NCCL_TOPO_CPU_ARCH_X86 && comm->cpuVendor == NCCL_TOPO_CPU_VENDOR_INTEL) return 1.0;
if (comm->cpuArch == NCCL_TOPO_CPU_ARCH_X86 && comm->cpuVendor == NCCL_TOPO_CPU_VENDOR_AMD) return 2.0;
return 1.0;
}
ncclResult_t ncclTopoTuneModel(struct ncclComm* comm, int minCompCap, int maxCompCap, struct ncclTopoGraph** graphs) {
int simpleDefaultThreads = (graphs[NCCL_ALGO_RING]->bwIntra*graphs[NCCL_ALGO_RING]->nChannels <= PCI_BW) ? 256 : NCCL_SIMPLE_MAX_NTHREADS;
comm->maxThreads[NCCL_ALGO_RING][NCCL_PROTO_SIMPLE] =
#if defined(__HIP_PLATFORM_AMD__) || defined(__HIPCC__)
getNthreads("NCCL_NTHREADS", ncclParamNthreads(), 4*comm->WarpSize, NCCL_MAX_NTHREADS, simpleDefaultThreads, comm->WarpSize);
comm->maxThreads[NCCL_ALGO_TREE][NCCL_PROTO_SIMPLE] = comm->maxThreads[NCCL_ALGO_COLLNET_DIRECT][NCCL_PROTO_SIMPLE] =
getNthreads("NCCL_NTHREADS", ncclParamNthreads(), 4*comm->WarpSize, NCCL_MAX_NTHREADS, NCCL_MAX_NTHREADS, comm->WarpSize);
comm->maxThreads[NCCL_ALGO_RING][NCCL_PROTO_LL] = comm->maxThreads[NCCL_ALGO_TREE][NCCL_PROTO_LL] = comm->maxThreads[NCCL_ALGO_COLLNET_DIRECT][NCCL_PROTO_LL] =
getNthreads("NCCL_NTHREADS", ncclParamNthreads(), 4*comm->WarpSize, NCCL_MAX_NTHREADS, NCCL_MAX_NTHREADS, comm->WarpSize);
comm->maxThreads[NCCL_ALGO_RING][NCCL_PROTO_LL128] = comm->maxThreads[NCCL_ALGO_TREE][NCCL_PROTO_LL128] =
getNthreads("NCCL_LL128_NTHREADS", ncclParamLl128Nthreads(), 4*comm->WarpSize, NCCL_LL128_MAX_NTHREADS, NCCL_LL128_MAX_NTHREADS, comm->WarpSize);
#else
getNthreads("NCCL_NTHREADS", ncclParamNthreads(), 2*WARP_SIZE, NCCL_SIMPLE_MAX_NTHREADS, simpleDefaultThreads);
comm->maxThreads[NCCL_ALGO_TREE][NCCL_PROTO_SIMPLE] =
getNthreads("NCCL_NTHREADS", ncclParamNthreads(), 2*WARP_SIZE, NCCL_SIMPLE_MAX_NTHREADS, NCCL_SIMPLE_MAX_NTHREADS);
comm->maxThreads[NCCL_ALGO_COLLNET_DIRECT][NCCL_PROTO_SIMPLE] =
comm->maxThreads[NCCL_ALGO_COLLNET_CHAIN][NCCL_PROTO_SIMPLE] =
comm->maxThreads[NCCL_ALGO_NVLS][NCCL_PROTO_SIMPLE] =
comm->maxThreads[NCCL_ALGO_NVLS_TREE][NCCL_PROTO_SIMPLE] = NCCL_MAX_NTHREADS;
comm->maxThreads[NCCL_ALGO_RING][NCCL_PROTO_LL] = comm->maxThreads[NCCL_ALGO_TREE][NCCL_PROTO_LL] =
getNthreads("NCCL_NTHREADS", ncclParamNthreads(), 2*WARP_SIZE, NCCL_LL_MAX_NTHREADS, NCCL_LL_MAX_NTHREADS);
comm->maxThreads[NCCL_ALGO_RING][NCCL_PROTO_LL128] = comm->maxThreads[NCCL_ALGO_TREE][NCCL_PROTO_LL128] =
getNthreads("NCCL_LL128_NTHREADS", ncclParamLl128Nthreads(), NCCL_LL128_MAX_NTHREADS/4, NCCL_LL128_MAX_NTHREADS, NCCL_LL128_MAX_NTHREADS);
#endif
int nNodes = comm->nNodes;
int nRanks = comm->nRanks;
if (nRanks <= 1) return ncclSuccess;
int compCapIndex = minCompCap >= 90 ? HOPPER_COMPCAP_IDX : minCompCap >= 80 ? AMPERE_COMPCAP_IDX : VOLTA_COMPCAP_IDX;
int cpuArch, cpuVendor, cpuModel;
NCCLCHECK(ncclTopoCpuType(comm->topo, &cpuArch, &cpuVendor, &cpuModel));
int index2 = nNodes <= 2 ? nNodes-1 : 2;
// LL: for single node, we look at GPU type; for multi-node, we look at CPU type
int index1 = nNodes == 1 ? compCapIndex : cpuVendor == NCCL_TOPO_CPU_VENDOR_AMD ? 1 : 0;
double llMaxBw = llMaxBws[index1][index2];
double perChMaxTreeBw = perChMaxTreeBws[compCapIndex][index2];
double perChMaxRingLL128Bw = perChMaxRingLL128Bws[compCapIndex][index2];
double perChMaxTreeLL128Bw = perChMaxTreeLL128Bws[compCapIndex][index2];
// De-penalize Tree/Simple latency on Power systems to favor Tree than Ring
//if (cpuArch == NCCL_TOPO_CPU_ARCH_POWER) hwLat[NCCL_HW_PCI][NCCL_ALGO_TREE][NCCL_PROTO_SIMPLE] = hwLat[NCCL_HW_PCI][NCCL_ALGO_RING][NCCL_PROTO_SIMPLE];
float ppn = (float)nRanks / nNodes;
int intraHw[NCCL_NUM_ALGORITHMS], hw[NCCL_NUM_ALGORITHMS];
for (int a=0; a<NCCL_NUM_ALGORITHMS; a++) intraHw[a] = graphs[a]->typeIntra == LINK_NVL ? NCCL_HW_NVLINK : NCCL_HW_PCI;
for (int a=0; a<NCCL_NUM_ALGORITHMS; a++) hw[a] = nNodes == 1 ? intraHw[a] : NCCL_HW_NET;
memcpy(comm->minMaxLLRange,
rcclTuningModel[comm->topo->tuning].llProtoRanges,
sizeof(rcclTuningModel[comm->topo->tuning].llProtoRanges));
for (int coll=0; coll<NCCL_NUM_FUNCTIONS; coll++) {
int nsteps = coll == ncclFuncAllReduce ? 2*(nRanks-1) :
coll == ncclFuncReduceScatter || coll == ncclFuncAllGather ? nRanks-1 :
nRanks;
for (int a=0; a<NCCL_NUM_ALGORITHMS; a++) {
if ((coll == ncclFuncBroadcast || coll == ncclFuncReduce) && a != NCCL_ALGO_RING) continue;
if ((coll == ncclFuncReduceScatter || coll == ncclFuncAllGather)
&& a != NCCL_ALGO_PAT && a != NCCL_ALGO_RING
&& a != NCCL_ALGO_NVLS && a != NCCL_ALGO_COLLNET_DIRECT) continue;
if (coll == ncclFuncAllReduce && a == NCCL_ALGO_PAT) continue;
for (int p=0; p<NCCL_NUM_PROTOCOLS; p++) {
if (a == NCCL_ALGO_TREE && p == NCCL_PROTO_SIMPLE && (IsArchMatch(comm->topo->nodes[GPU].nodes[0].gpu.gcn, "gfx942") || IsArchMatch(comm->topo->nodes[GPU].nodes[0].gpu.gcn, "gfx950")) && comm->topo->nodes[GPU].count == comm->topo->nRanks) continue;
if ((a == NCCL_ALGO_NVLS || a == NCCL_ALGO_NVLS_TREE) && p != NCCL_PROTO_SIMPLE) continue;
if ((coll == ncclFuncReduceScatter || coll == ncclFuncAllGather)
&& a == NCCL_ALGO_PAT && (p != NCCL_PROTO_SIMPLE || ncclPatEnable(comm) == 0)) continue;
int collnet = (a == NCCL_ALGO_COLLNET_DIRECT || a == NCCL_ALGO_COLLNET_CHAIN) ? 1 : 0;
float bw = nNodes <= 2 || collnet ? graphs[a]->bwIntra : graphs[a]->bwInter;
float busBw = comm->topo->baseBw != 0.0 ? comm->topo->baseBw : graphs[a]->nChannels * bw;
//INFO(NCCL_INIT, "algo %s proto %s busBw %f baseBw %f bw %f nChannels %d bwIntra %f bwInter %f", ncclAlgoStr[a], ncclProtoStr[p], busBw, comm->topo->baseBw, bw, graphs[a]->nChannels, graphs[a]->bwIntra, graphs[a]->bwInter);
if (a == NCCL_ALGO_NVLS) bw = std::min(graphs[a]->bwIntra, graphs[a]->bwInter);
if (a == NCCL_ALGO_NVLS_TREE) bw = std::min(graphs[a]->bwIntra, nNodes <= 2 ? graphs[a]->bwInter : graphs[a]->bwInter/2);
// Various model refinements
#if defined(__HIP_PLATFORM_AMD__) || defined(__HIPCC__)
if (nNodes <= 2)
busBw *= rcclTuningModel[comm->topo->tuning].bwRatio[0][a][p];
else
busBw *= rcclTuningModel[comm->topo->tuning].bwRatio[1][a][p];
if (a == NCCL_ALGO_RING && p == NCCL_PROTO_LL && (coll == ncclFuncBroadcast || coll == ncclFuncReduce) && (IsArchMatch(comm->topo->nodes[GPU].nodes[0].gpu.gcn, "gfx942") || IsArchMatch(comm->topo->nodes[GPU].nodes[0].gpu.gcn, "gfx950")) && comm->topo->nodes[GPU].count == comm->topo->nRanks) { busBw = busBw * 1.65; }
#else
if (a == NCCL_ALGO_RING && p == NCCL_PROTO_LL) { busBw = std::min(llMaxBw, busBw * .5); }
if (a == NCCL_ALGO_RING && p == NCCL_PROTO_LL128) busBw = std::min(busBw * (0.92 /*120.0/128.0*/), graphs[a]->nChannels*perChMaxRingLL128Bw);
if (a == NCCL_ALGO_TREE && coll == ncclFuncAllReduce) busBw = std::min(busBw*.92, graphs[a]->nChannels*perChMaxTreeBw);
if (a == NCCL_ALGO_TREE && p == NCCL_PROTO_LL) busBw = std::min(busBw*1.0/3.8, llMaxBw);
if (a == NCCL_ALGO_TREE && p == NCCL_PROTO_LL128) busBw = std::min(busBw * (nNodes == 1 ? 7.0/9.0 : 120.0/128.0), graphs[a]->nChannels*perChMaxTreeLL128Bw);
if (a == NCCL_ALGO_TREE && graphs[a]->pattern == NCCL_TOPO_PATTERN_TREE) busBw *= .85;
if (a == NCCL_ALGO_PAT) busBw *= .85;
if (a == NCCL_ALGO_COLLNET_DIRECT && p != NCCL_PROTO_SIMPLE) busBw = 0; // Not used
if (a == NCCL_ALGO_COLLNET_CHAIN && p != NCCL_PROTO_SIMPLE) busBw = 0; // Not used
if (a == NCCL_ALGO_COLLNET_DIRECT && p == NCCL_PROTO_SIMPLE) {
if (coll == ncclFuncAllGather || coll == ncclFuncReduceScatter) {
busBw = ppn * bw;
// AllGather/ReduceScatter requires 1:1 GPU:NIC
int nicPerNode = comm->collNetHeadsNum;
if (coll == ncclFuncAllGather && comm->nNodes > 1) {
if (!comm->ncclCollNet || !comm->ncclCollNet->iallgather || ppn > nicPerNode) busBw = 0;
}
if (coll == ncclFuncReduceScatter && comm->nNodes > 1) {
if (!comm->ncclCollNet || !comm->ncclCollNet->ireducescatter || ppn > nicPerNode) busBw = 0;
}
// Measured corrective ratio needed at 1 ppn and 8ppn. Here we hackishly
// interpolate the two.
float w = (ppn-1)/(8-1);
busBw *= w*0.85 + (1-w)*0.95;
} else {
// Collnet+Direct requires all GPUs to have a local NIC to work at full speed
float factor = ppn / (1.0*graphs[a]->nChannels); // GPU/NIC ratio
factor -= (factor-1)/2;
busBw /= factor;
if (minCompCap >= 90) busBw *= .85;
}
}
#endif
// Convert bus BW to algorithm BW
if (!(a != NCCL_ALGO_RING && (coll == ncclFuncAllGather || coll == ncclFuncReduceScatter))) {
float ratio = 1.0f;
if (a == NCCL_ALGO_RING) ratio *= (1.0 * nRanks) / nsteps;
else if (a == NCCL_ALGO_NVLS || a == NCCL_ALGO_NVLS_TREE) ratio *= 5.0/6.0;
else ratio *= .5;
busBw *= ratio;
}
comm->bandwidths[coll][a][p] = busBw;
/* Ring bandwidth backup */
if (a == NCCL_ALGO_RING)
comm->ringbdw[coll][p] = comm->bandwidths[coll][NCCL_ALGO_RING][p];
comm->latencies[coll][a][p] = baseLat[a][p];
float intraLat = rcclTuningModel[comm->topo->tuning].hwLat[intraHw[a]][a][p];
float interLat = ppn == 1 ? rcclTuningModel[comm->topo->tuning].hwLat[NCCL_HW_NET][NCCL_ALGO_TREE][p] : rcclTuningModel[comm->topo->tuning].hwLat[NCCL_HW_NET][a][p];
interLat += graphs[a]->latencyInter;
// Also add the flush extra latency
if (p == NCCL_PROTO_SIMPLE) interLat += graphs[a]->latencyInter;
if (a == NCCL_ALGO_RING) {
float lat = rcclTuningModel[comm->topo->tuning].hwLat[hw[a]][a][p];
if ((coll == ncclFuncReduce || coll == ncclFuncBroadcast)) {
if (graphs[a]->sameChannels) {
comm->latencies[coll][a][p] += lat;
} else {
if (p == NCCL_PROTO_SIMPLE) lat = rcclTuningModel[comm->topo->tuning].hwLat[hw[a]][NCCL_ALGO_TREE][p]; // Add some chunk latency, waiting for proper chunk modeling
comm->latencies[coll][a][p] += nsteps*lat;
}
} else {
// Inter-node rings still have to launch nsteps * net overhead.
float netOverhead = 0.0;
if (nNodes > 1) {
netOverhead = getNetOverhead(comm);
if (p == NCCL_PROTO_SIMPLE) netOverhead *= 3;
}
intraLat = std::max(intraLat, netOverhead);
int nInterSteps = nNodes == 1 ? 0 : coll == ncclFuncAllReduce ? 2*(nNodes-1) : nNodes-1;
comm->latencies[coll][a][p] += (nsteps-nInterSteps)*intraLat + nInterSteps*interLat;
}
} else if (a == NCCL_ALGO_TREE) {
if (coll == ncclFuncAllReduce) {
comm->latencies[coll][a][p] +=
2 * ((nRanks/nNodes-1) * intraLat + log2i(nNodes) * interLat);
}
} else if (a == NCCL_ALGO_COLLNET_DIRECT) {
comm->latencies[coll][a][p] +=
2 * (std::min(1, (nRanks/nNodes-1)) * intraLat + (nRanks/nNodes-1) * 0.4) + interLat; // Add 0.4 us arity serialization latency
} else if (a == NCCL_ALGO_COLLNET_CHAIN) {
comm->latencies[coll][a][p] += 2 * (nRanks/nNodes-1) * intraLat + interLat;
} else if (a == NCCL_ALGO_NVLS) {
if (nNodes > 1) comm->latencies[coll][a][p] += rcclTuningModel[comm->topo->tuning].hwLat[NCCL_HW_NET][a][p];
} else if (a == NCCL_ALGO_NVLS_TREE) {
comm->latencies[coll][a][p] += 2*(nNodes-1)*rcclTuningModel[comm->topo->tuning].hwLat[NCCL_HW_NET][a][p];
} else if (a == NCCL_ALGO_PAT) {
if (coll == ncclFuncAllGather || coll == ncclFuncReduceScatter) {
comm->latencies[coll][a][p] = 8 // Base time
+ log2i(nNodes) * (interLat/3.5) // Log latency
+ nRanks * 2.8; // Still a linear part; hopefully we'll manage to remove it at some point.
}
}
}
}
}
// Protocols/Algorithms enable/disable, and user overrides.
// All are enabled except ll128 which is enabled by default only in certain cases.
int protoEnable[NCCL_NUM_PROTOCOLS] = { 1, 2, 1 };
int algoEnable[NCCL_NUM_ALGORITHMS] = { 1, 1, 1, 1, 1, 1, 1 };
const char *protoStr = ncclGetEnv("NCCL_PROTO");
if (protoStr) {
INFO(NCCL_ENV, "NCCL_PROTO set by environment to %s", protoStr);
NCCLCHECK(parseList(protoStr, ncclProtoStr, NCCL_NUM_PROTOCOLS, protoEnable));
}
const char *algoStr = ncclGetEnv("NCCL_ALGO");
if (algoStr) {
INFO(NCCL_ENV, "NCCL_ALGO set by environment to %s", algoStr);
NCCLCHECK(parseList(algoStr, ncclAlgoStr, NCCL_NUM_ALGORITHMS, algoEnable));
}
if (comm->nNodes == 1) algoEnable[NCCL_ALGO_NVLS_TREE] = 0;
// Disable CollNet if it is not supported
if (comm->collNetSupport == 0) {
algoEnable[NCCL_ALGO_COLLNET_DIRECT] = 0;
algoEnable[NCCL_ALGO_COLLNET_CHAIN] = 0;
if (nNodes > 1) algoEnable[NCCL_ALGO_NVLS] = 0;
// If user has hard set NCCL_ALGO=COLLNET, ignore it
if (algoEnable[NCCL_ALGO_RING] == 0 && algoEnable[NCCL_ALGO_TREE] == 0 &&
algoEnable[NCCL_ALGO_NVLS] == 0 && algoEnable[NCCL_ALGO_NVLS_TREE] == 0) {
algoEnable[NCCL_ALGO_RING] = algoEnable[NCCL_ALGO_TREE] = 1;
}
} else {
// Disable CollNet+Direct if not on an NVSwitch system
int nvsCount = 0;
NCCLCHECK(ncclTopoGetNvsCount(comm->topo, &nvsCount));
if (nvsCount == 0) algoEnable[NCCL_ALGO_COLLNET_DIRECT] = 0;
}
for (int c=0; c<NCCL_NUM_FUNCTIONS; c++) for (int a=0; a<NCCL_NUM_ALGORITHMS; a++) for (int p=0; p<NCCL_NUM_PROTOCOLS; p++) {
// Disable LL protocol on gfx12xx
int pEnable = (p == NCCL_PROTO_LL && IsArchMatch(comm->topo->nodes[GPU].nodes[0].gpu.gcn, "gfx12")) ? 0 : protoEnable[p];
if (p == NCCL_PROTO_LL128) {
#if defined(__HIP_PLATFORM_AMD__) || defined(__HIPCC__)
#if defined(ENABLE_LL128)
// Enable LL128 by default only on gfx90a with available tuning table
pEnable = (graphs[a]->typeInter <= PATH_PXB) && graphs[a]->typeIntra <= PATH_NVL &&
((IsArchMatch(comm->topo->nodes[GPU].nodes[0].gpu.gcn, "gfx90a") ||
IsArchMatch(comm->topo->nodes[GPU].nodes[0].gpu.gcn, "gfx942")) && comm->topo->ll128Enabled) ? 1 : 0;
#else
pEnable = 0;
#endif
#else
// Enable LL128 by default only on Volta/Ampere/Hopper+NVLink. Other cases are not tested and may cause silent data corruption.
pEnable = 1;
pEnable &= (graphs[a]->typeInter <= PATH_PXB || (minCompCap >= 90 && graphs[a]->typeInter <= PATH_PXN));
pEnable &= (graphs[a]->typeIntra <= PATH_NVB);
pEnable &= (minCompCap == maxCompCap);
switch (minCompCap) {
case 70: pEnable &= 1; break;
case 80: pEnable &= 1; break;
case 90: pEnable &= !(CUDART_VERSION == 11080 && c == ncclFuncAllReduce && a == NCCL_ALGO_RING && comm->nRanks == 2); break;
default: pEnable &= 0; break;
}
#endif
}
if (pEnable == 0) comm->bandwidths[c][a][p] = 0;
if (algoEnable[a] == 0) comm->bandwidths[c][a][p] = 0;
//if (a == NCCL_ALGO_RING && pEnable == 0) comm->ringbdw[c][p] = 0;
}
for (int c = 0; c < NCCL_NUM_FUNCTIONS; c++) {
bool available = false;
for (int a = 0; a < NCCL_NUM_ALGORITHMS; a++)
for (int p = 0; p < NCCL_NUM_PROTOCOLS; p++)
if (comm->bandwidths[c][a][p] != 0) {
available = true;
goto check_avail;
}
check_avail:
if (available == false) {
/* at least set ring algo available */
for (int p = 0; p < NCCL_NUM_PROTOCOLS; p++)
comm->bandwidths[c][NCCL_ALGO_RING][p] = comm->ringbdw[c][p];
}
}
if (comm->rank == 0) {
char line[1024];
for (int block=0; block<DIVUP(NCCL_NUM_ALGORITHMS, 3); block++) {
sprintf(line, " Algorithm |");
for (int ba=0; ba<3; ba++) {
int a = block*3+ba;
if (a >= NCCL_NUM_ALGORITHMS) continue;
sprintf(line+strlen(line), " %14s %14s %14s |", "", ncclAlgoStr[a], "");
}
INFO(NCCL_TUNING, "%s", line);
sprintf(line, " Protocol |");
for (int ba=0; ba<3; ba++) {
for (int p=0; p<NCCL_NUM_PROTOCOLS; p++) {
sprintf(line+strlen(line), " %14s |", ncclProtoStr[p]);
}
}
INFO(NCCL_TUNING, "%s", line);
sprintf(line, " Max NThreads |");
for (int ba=0; ba<3; ba++) {
int a = block*3+ba;
if (a >= NCCL_NUM_ALGORITHMS) continue;
for (int p=0; p<NCCL_NUM_PROTOCOLS; p++) {
sprintf(line+strlen(line), " %14d |", comm->maxThreads[a][p]);
}
}
INFO(NCCL_TUNING, "%s", line);
for (int c=0; c<NCCL_NUM_FUNCTIONS; c++) {
sprintf(line, "%13s |", ncclFuncStr[c]);
for (int ba=0; ba<3; ba++) {
int a = block*3+ba;
if (a >= NCCL_NUM_ALGORITHMS) continue;
for (int p=0; p<NCCL_NUM_PROTOCOLS; p++) {
sprintf(line+strlen(line), "%8.1f/%6.1f |", comm->latencies[c][a][p], comm->bandwidths[c][a][p]);
}
}
INFO(NCCL_TUNING, "%s", line);
}
}
}
// Set per-thread amount of work before we increase nThreads and nChannels
for (int a=0; a<NCCL_NUM_ALGORITHMS; a++) {
comm->threadThresholds[a][NCCL_PROTO_LL] = NCCL_LL_THREAD_THRESHOLD;
comm->threadThresholds[a][NCCL_PROTO_LL128] = NCCL_LL128_THREAD_THRESHOLD;
comm->threadThresholds[a][NCCL_PROTO_SIMPLE] = NCCL_SIMPLE_THREAD_THRESHOLD;
}
comm->threadThresholds[NCCL_ALGO_RING][NCCL_PROTO_LL] *= nRanks;
comm->threadThresholds[NCCL_ALGO_COLLNET_DIRECT][NCCL_PROTO_SIMPLE] = 256;
comm->threadThresholds[NCCL_ALGO_COLLNET_CHAIN][NCCL_PROTO_SIMPLE] = 256;
// Override defaults with user env
const char* str = ncclGetEnv("NCCL_THREAD_THRESHOLDS");
if (str) {
INFO(NCCL_ENV, "NCCL_THREAD_THRESHOLDS set by environment to %s", str);
ssize_t t[2][NCCL_NUM_PROTOCOLS] = {{ -2, -2, -2 }, { -2, -2, -2 }};
sscanf(str, "%ld %ld %ld %ld %ld %ld", t[0], t[0]+1, t[0]+2, t[1], t[1]+1, t[1]+2);
for (int a=0; a<2; a++) {
for (int p=0; p<NCCL_NUM_PROTOCOLS; p++) {
if (t[a][p] >= 0) comm->threadThresholds[a][p] = t[a][p];
}
}
}
INFO(NCCL_INIT, "threadThresholds %ld/%ld/%ld | %ld/%ld/%ld | %ld | %ld",
comm->threadThresholds[NCCL_ALGO_TREE][NCCL_PROTO_LL],
comm->threadThresholds[NCCL_ALGO_TREE][NCCL_PROTO_LL128],
comm->threadThresholds[NCCL_ALGO_TREE][NCCL_PROTO_SIMPLE],
comm->threadThresholds[NCCL_ALGO_RING][NCCL_PROTO_LL],
comm->threadThresholds[NCCL_ALGO_RING][NCCL_PROTO_LL128],
comm->threadThresholds[NCCL_ALGO_RING][NCCL_PROTO_SIMPLE],
comm->threadThresholds[NCCL_ALGO_COLLNET_DIRECT][NCCL_PROTO_SIMPLE],
comm->threadThresholds[NCCL_ALGO_COLLNET_CHAIN][NCCL_PROTO_SIMPLE]);
return ncclSuccess;
}
// Trees are not perfectly sticking to the model for medium sizes. Applying a static correction
// factor is not ideal but works quite well. Powers of two, 64 B to 256MB.
static float treeCorrectionFactor[NCCL_NUM_PROTOCOLS][23] = {
{ 1.0, 1.0, 1.0, 1.0, .9, .8, .7, .7, .7, .7, .6, .5, .4, .4, .5, .6, .7, .8, .9, 1.0, 1.0, 1.0, 1.0 },
{ 1.0, 1.0, 1.0, 1.0, 1.0, .9, .8, .8, .8, .7, .6, .6, .6, .6, .6, .6, .8, .9, .9, .9, .9, 1.0, 1.0 },
{ .9, .9, .9, .9, .9, .9, .9, .8, .7, .6, .6, .5, .5, .5, .5, .6, .7, .8, .7, .7, .8, .9, .9 }
};
ncclResult_t ncclTopoGetAlgoTime(struct ncclComm* comm, int coll, int algorithm, int protocol, size_t nBytes, int numPipeOps, float* time, bool* backup) {
float bw = comm->bandwidths[coll][algorithm][protocol];
float lat = comm->latencies[coll][algorithm][protocol];
if (backup) {
*backup = false;
if (algorithm == NCCL_ALGO_RING && bw == 0.0f) {
/* try back up RING algorithm */
bw = comm->ringbdw[coll][protocol];
*backup = true;
}
}
if (bw == 0) {
*time = -1.0; return ncclSuccess;
}
int logSize = log2i(nBytes>>6);
#if defined(__HIP_PLATFORM_AMD__) || defined(__HIPCC__)
if (algorithm == NCCL_ALGO_TREE) {
if (logSize < 27) bw *= rcclTuningModel[comm->topo->tuning].treeCorrectionFactor[protocol][logSize];
else bw *= rcclTuningModel[comm->topo->tuning].treeCorrectionFactor[protocol][26];
}
else if (algorithm == NCCL_ALGO_RING && comm->nNodes > 1) {
if(logSize < 27) bw *= rcclTuningModel[comm->topo->tuning].ringCorrectionFactor[protocol][logSize];
else bw *= rcclTuningModel[comm->topo->tuning].ringCorrectionFactor[protocol][26];
}
#else
if (algorithm == NCCL_ALGO_TREE && coll == ncclFuncAllReduce && logSize >= 0 && logSize < 23) bw *= treeCorrectionFactor[protocol][logSize];
if (algorithm == NCCL_ALGO_RING && protocol == NCCL_PROTO_SIMPLE && comm->nNodes > 1
&& coll == ncclFuncAllReduce && nBytes/(comm->nChannels*comm->nRanks) >= 64) {
lat *= comm->minCompCap < 80 ? 1.9 : 1.4; // Plateau effect of ring
}
#endif
// Tree pipelining saves latency in aggregation cases
int latCount = algorithm == NCCL_ALGO_RING ? numPipeOps : DIVUP(numPipeOps, NCCL_MAX_DEV_WORK_BATCH_COLLS);
*time = lat * latCount + nBytes / (1000 * bw);
return ncclSuccess;
}