nccl/src/transport/net.cc
2020-03-26 17:31:24 -07:00

371 lines
16 KiB
C++

/*************************************************************************
* Copyright (c) 2016-2019, NVIDIA CORPORATION. All rights reserved.
*
* See LICENSE.txt for license information
************************************************************************/
#include "comm.h"
#include "net.h"
#include "graph.h"
struct netConnectInfo {
ncclNetHandle_t netHandle;
};
struct netSendResources {
void* netSendComm;
struct ncclSendMem* hostSendMem;
struct ncclRecvMem* hostRecvMem;
struct ncclSendMem* devHostSendMem;
struct ncclRecvMem* devHostRecvMem;
int netDev;
int useGdr;
int buffSize;
void* mhandle;
void* llMhandle;
void* ll128Mhandle;
struct ncclRecvMem* devRecvMem;
uint64_t step;
uint64_t llLastCleaning;
};
struct netRecvResources {
void* netListenComm;
void* netRecvComm;
struct ncclSendMem* hostSendMem;
struct ncclRecvMem* hostRecvMem;
struct ncclSendMem* devHostSendMem;
struct ncclRecvMem* devHostRecvMem;
int netDev;
int useGdr;
int buffSize;
void* mhandle;
void* llMhandle;
void* ll128Mhandle;
struct ncclRecvMem* devRecvMem;
uint64_t step;
uint64_t llLastCleaning;
};
/* Determine if two peers can communicate with NET */
ncclResult_t netCanConnect(int* ret, struct ncclTopoSystem* topo, struct ncclTopoGraph* graph, struct ncclPeerInfo* info1, struct ncclPeerInfo* info2) {
*ret = 1;
return ncclSuccess;
}
/* Determine if we will use this transport for this peer and return connect
* information for this peer */
ncclResult_t netSendSetup(struct ncclTopoSystem* topo, struct ncclTopoGraph* graph, struct ncclPeerInfo* myInfo, struct ncclPeerInfo* peerInfo, struct ncclConnect* connectInfo, struct ncclConnector* send, int buffSize, int channelId) {
struct netSendResources* resources;
NCCLCHECK(ncclCalloc(&resources, 1));
send->transportResources = resources;
NCCLCHECK(ncclTopoGetNetDev(graph, 1, channelId, &resources->netDev));
NCCLCHECK(ncclTopoCheckGdr(topo, myInfo->busId, resources->netDev, 1, &resources->useGdr));
int sendSize = sizeof(struct ncclSendMem);
NCCLCHECK(ncclCudaHostAlloc((void**)&resources->hostSendMem, (void**)&resources->devHostSendMem, sendSize));
int recvSize = offsetof(struct ncclRecvMem, buff)+buffSize;
if (resources->useGdr) {
NCCLCHECK(ncclCudaCalloc((char**)(&resources->devRecvMem), recvSize));
}
NCCLCHECK(ncclCudaHostAlloc((void**)&resources->hostRecvMem, (void**)&resources->devHostRecvMem, recvSize));
resources->buffSize = buffSize;
INFO(NCCL_INIT|NCCL_NET,"Ring %02d : %d[%lx] -> %d[%lx] [send] via NET/%s/%d%s", channelId, myInfo->rank, myInfo->busId, peerInfo->rank, peerInfo->busId, ncclNetName(), resources->netDev,
resources->useGdr ? "/GDRDMA" : "");
return ncclSuccess;
}
ncclResult_t netRecvSetup(struct ncclTopoSystem* topo, struct ncclTopoGraph* graph, struct ncclPeerInfo* myInfo, struct ncclPeerInfo* peerInfo, struct ncclConnect* connectInfo, struct ncclConnector* recv, int buffSize, int channelId) {
struct netRecvResources* resources;
NCCLCHECK(ncclCalloc(&resources, 1));
recv->transportResources = resources;
NCCLCHECK(ncclTopoGetNetDev(graph, 0, channelId, &resources->netDev));
NCCLCHECK(ncclTopoCheckGdr(topo, myInfo->busId, resources->netDev, 0, &resources->useGdr));
int sendSize = sizeof(struct ncclSendMem);
NCCLCHECK(ncclCudaHostAlloc((void**)&resources->hostSendMem, (void**)&resources->devHostSendMem, sendSize));
int recvSize = offsetof(struct ncclRecvMem, buff)+buffSize;
if (resources->useGdr) {
NCCLCHECK(ncclCudaCalloc((char**)(&resources->devRecvMem), recvSize));
}
NCCLCHECK(ncclCudaHostAlloc((void**)&resources->hostRecvMem, (void**)&resources->devHostRecvMem, recvSize));
resources->buffSize = buffSize;
INFO(NCCL_INIT|NCCL_NET,"Ring %02d : %d[%lx] -> %d[%lx] [receive] via NET/%s/%d%s", channelId, peerInfo->rank, peerInfo->busId, myInfo->rank, myInfo->busId, ncclNetName(), resources->netDev,
resources->useGdr ? "/GDRDMA" : "");
struct netConnectInfo* info = (struct netConnectInfo*) connectInfo;
NCCLCHECK(ncclNetListen(resources->netDev, &info->netHandle, &resources->netListenComm));
return ncclSuccess;
}
ncclResult_t netSendConnect(struct ncclConnect* connectInfo, int nranks, int rank, struct ncclConnector* send) {
// Setup device pointers
struct netSendResources* resources = (struct netSendResources*)send->transportResources;
// Intermediate buffering on GPU for GPU Direct RDMA, but LL buffer is always on host
struct ncclRecvMem* recvMem = resources->useGdr ? resources->devRecvMem : resources->devHostRecvMem;
send->conn.buff = recvMem->buff;
send->conn.llBuff = resources->devHostRecvMem->llBuff;
send->conn.ll128Buff = recvMem->ll128Buff;
send->conn.direct |= resources->useGdr ? NCCL_DIRECT_NIC : 0;
// Head/Tail/Opcount/Fifos are always on host
send->conn.tail = &resources->devHostRecvMem->tail;
send->conn.opCountRem = &resources->devHostRecvMem->opCount;
send->conn.fifo = resources->devHostRecvMem->sizesFifo;
send->conn.head = &resources->devHostSendMem->head;
send->conn.opCountLoc = &resources->devHostSendMem->opCount;
for (int i=0; i<NCCL_STEPS; i++) send->conn.fifo[i] = -1;
// Connect to remote peer
struct netConnectInfo* info = (struct netConnectInfo*)connectInfo;
NCCLCHECK(ncclNetConnect(resources->netDev, info->netHandle, &resources->netSendComm));
NCCLCHECK(ncclNetRegMr(resources->netSendComm, recvMem->buff, resources->buffSize,
resources->useGdr ? NCCL_PTR_CUDA : NCCL_PTR_HOST, &resources->mhandle));
NCCLCHECK(ncclNetRegMr(resources->netSendComm, resources->devHostRecvMem->llBuff,
NCCL_LL_BUFF_SIZE, NCCL_PTR_HOST, &resources->llMhandle));
NCCLCHECK(ncclNetRegMr(resources->netSendComm, recvMem->ll128Buff, NCCL_LL128_BUFF_SIZE,
resources->useGdr ? NCCL_PTR_CUDA : NCCL_PTR_HOST, &resources->ll128Mhandle));
return ncclSuccess;
}
/* Connect to this peer */
ncclResult_t netRecvConnect(struct ncclConnect* connectInfo, int nranks, int rank, struct ncclConnector* recv) {
// Setup device pointers
struct netRecvResources* resources = (struct netRecvResources*)recv->transportResources;
// Intermediate buffering on GPU for GPU Direct RDMA
struct ncclRecvMem* recvMem = resources->useGdr ? resources->devRecvMem : resources->devHostRecvMem;
recv->conn.buff = recvMem->buff;
recv->conn.llBuff = recvMem->llBuff;
recv->conn.ll128Buff = recvMem->ll128Buff;
recv->conn.direct |= resources->useGdr ? NCCL_DIRECT_NIC : 0;
// Head/Tail/Opcount are always on host
recv->conn.tail = &resources->devHostRecvMem->tail;
recv->conn.opCountLoc = &resources->devHostRecvMem->opCount;
recv->conn.head = &resources->devHostSendMem->head;
recv->conn.opCountRem = &resources->devHostSendMem->opCount;
// Finish connection establishment from remote peer
NCCLCHECK(ncclNetAccept(resources->netListenComm, &resources->netRecvComm));
NCCLCHECK(ncclNetCloseListen(resources->netListenComm));
NCCLCHECK(ncclNetRegMr(resources->netRecvComm, recvMem->buff, resources->buffSize,
resources->useGdr ? NCCL_PTR_CUDA : NCCL_PTR_HOST, &resources->mhandle));
NCCLCHECK(ncclNetRegMr(resources->netRecvComm, recvMem->llBuff, NCCL_LL_BUFF_SIZE,
resources->useGdr ? NCCL_PTR_CUDA : NCCL_PTR_HOST, &resources->llMhandle));
NCCLCHECK(ncclNetRegMr(resources->netRecvComm, recvMem->ll128Buff, NCCL_LL128_BUFF_SIZE,
resources->useGdr ? NCCL_PTR_CUDA : NCCL_PTR_HOST, &resources->ll128Mhandle));
return ncclSuccess;
}
ncclResult_t netSendFree(void* transportResources) {
struct netSendResources* resources = (struct netSendResources*)transportResources;
NCCLCHECK(ncclCudaHostFree(resources->hostSendMem));
NCCLCHECK(ncclNetDeregMr(resources->netSendComm, resources->mhandle));
NCCLCHECK(ncclNetDeregMr(resources->netSendComm, resources->llMhandle));
NCCLCHECK(ncclNetDeregMr(resources->netSendComm, resources->ll128Mhandle));
NCCLCHECK(ncclCudaHostFree(resources->hostRecvMem));
if (resources->useGdr)
CUDACHECK(cudaFree(resources->devRecvMem));
NCCLCHECK(ncclNetCloseSend(resources->netSendComm));
free(resources);
return ncclSuccess;
}
ncclResult_t netRecvFree(void* transportResources) {
struct netRecvResources* resources = (struct netRecvResources*)transportResources;
NCCLCHECK(ncclCudaHostFree(resources->hostSendMem));
NCCLCHECK(ncclNetDeregMr(resources->netRecvComm, resources->mhandle));
NCCLCHECK(ncclNetDeregMr(resources->netRecvComm, resources->llMhandle));
NCCLCHECK(ncclNetDeregMr(resources->netRecvComm, resources->ll128Mhandle));
NCCLCHECK(ncclCudaHostFree(resources->hostRecvMem));
if (resources->useGdr)
CUDACHECK(cudaFree(resources->devRecvMem));
NCCLCHECK(ncclNetCloseRecv(resources->netRecvComm));
free(resources);
return ncclSuccess;
}
ncclResult_t netSendProxy(struct ncclProxyArgs* args) {
struct netSendResources* resources = (struct netSendResources*) (args->connector->transportResources);
if (args->state == ncclProxyOpReady) {
// Update opCount
resources->hostRecvMem->opCount = args->opCount;
// Round to next multiple of sliceSteps
resources->step = ROUNDUP(resources->step, args->chunkSteps);
args->head = resources->step;
args->tail = resources->step;
args->end = args->head + args->nsteps;
args->state = ncclProxyOpProgress;
}
if (args->state == ncclProxyOpProgress) {
args->idle = 1;
if (args->head < args->end) {
if (args->tail < args->end && args->tail < args->head + NCCL_STEPS) {
volatile int* sizesFifo = resources->hostRecvMem->sizesFifo;
volatile uint64_t* recvTail = &resources->hostRecvMem->tail;
if (args->protocol == NCCL_PROTO_LL128) {
int stepSize = NCCL_LL128_BUFF_SIZE/NCCL_STEPS;
if (args->tail < *recvTail) {
int buffSlot = args->tail%NCCL_STEPS;
if (sizesFifo[buffSlot] != -1) {
struct ncclRecvMem* localMem = resources->useGdr ? resources->devRecvMem : resources->hostRecvMem;
char* localBuff = (char*)localMem->ll128Buff;
int ready = resources->useGdr;
if (!ready) {
// When data is in sysmem, we need to wait until all flags are correct since the GPU only
// called threadfence()
uint64_t flag = args->tail + 1;
int nFifoLines = DIVUP(sizesFifo[buffSlot], sizeof(uint64_t)*NCCL_LL128_LINEELEMS);
volatile uint64_t* lines = (volatile uint64_t*)(localBuff+buffSlot*stepSize);
ready = 1;
for (int i=0; i<nFifoLines; i++) {
if (lines[i*NCCL_LL128_LINEELEMS+NCCL_LL128_DATAELEMS] != flag) { ready = 0; break; }
}
}
if (ready) {
// Send through network
NCCLCHECK(ncclNetIsend(resources->netSendComm, localBuff+buffSlot*stepSize, sizesFifo[buffSlot], resources->ll128Mhandle, args->requests+buffSlot));
if (args->requests[buffSlot] != NULL) {
sizesFifo[buffSlot] = -1;
// Make sure size is reset to zero before we update the head.
__sync_synchronize();
args->tail += args->sliceSteps;
args->idle = 0;
}
}
}
}
} else if (args->protocol == NCCL_PROTO_LL) {
int buffSlot = args->tail%NCCL_STEPS;
int size = sizesFifo[buffSlot];
if (size != -1) {
uint32_t flag = NCCL_LL_FLAG(args->tail + 1);
int nFifoLines = DIVUP(size, sizeof(union ncclLLFifoLine));
size = nFifoLines * sizeof(union ncclLLFifoLine);
union ncclLLFifoLine* lines = resources->hostRecvMem->llBuff+buffSlot*NCCL_LL_SLICE_LINES;
int ready = 1;
for (int i=0; i<nFifoLines; i++) {
volatile uint32_t *f1 = &lines[i].flag1;
volatile uint32_t *f2 = &lines[i].flag2;
if (f1[0] != flag || f2[0] != flag) { ready = 0; break; }
}
if (ready) {
NCCLCHECK(ncclNetIsend(resources->netSendComm, lines, size, resources->llMhandle, args->requests+buffSlot));
if (args->requests[buffSlot] != NULL) {
sizesFifo[buffSlot] = -1;
// Make sure size is reset to zero before we update the head.
__sync_synchronize();
args->tail += args->sliceSteps;
args->idle = 0;
}
}
}
} else if (args->tail < *recvTail) {
int stepSize = args->channel->buffSize/NCCL_STEPS;
struct ncclRecvMem* localMem = resources->useGdr ? resources->devRecvMem : resources->hostRecvMem;
// Send through network
int buffSlot = args->tail%NCCL_STEPS;
if (sizesFifo[buffSlot] != -1) {
NCCLCHECK(ncclNetIsend(resources->netSendComm, localMem->buff+buffSlot*stepSize, sizesFifo[buffSlot], resources->mhandle, args->requests+buffSlot));
if (args->requests[buffSlot] != NULL) {
sizesFifo[buffSlot] = -1;
// Make sure size is reset to zero before we update the head.
__sync_synchronize();
args->tail += args->sliceSteps;
args->idle = 0;
}
}
}
}
if (args->head < args->tail) {
int done;
int buffSlot = args->head%NCCL_STEPS;
NCCLCHECK(ncclNetTest(args->requests[buffSlot], &done, NULL));
if (done) {
args->head += args->sliceSteps;
resources->hostSendMem->head = args->head;
args->idle = 0;
}
}
}
if (args->head == args->end) {
resources->step = args->end;
args->idle = 0;
args->state = ncclProxyOpNone;
}
}
return ncclSuccess;
}
ncclResult_t netRecvProxy(struct ncclProxyArgs* args) {
struct netRecvResources* resources = (struct netRecvResources*) (args->connector->transportResources);
if (args->state == ncclProxyOpReady) {
// Update opCount
resources->hostSendMem->opCount = args->opCount;
// Round to next multiple of sliceSteps
resources->step = ROUNDUP(resources->step, args->chunkSteps);
args->head = resources->step;
args->tail = resources->step;
args->end = args->head + args->nsteps;
args->state = ncclProxyOpProgress;
}
if (args->state == ncclProxyOpProgress) {
args->idle = 1;
int stepSize = ( args->protocol == NCCL_PROTO_LL ? NCCL_LL_BUFF_SIZE : args->protocol == NCCL_PROTO_LL128 ? NCCL_LL128_BUFF_SIZE : args->channel->buffSize ) / NCCL_STEPS;
if (args->head < args->end) {
struct ncclRecvMem* localMem = resources->useGdr ? resources->devRecvMem : resources->hostRecvMem;
char* localBuff = args->protocol == NCCL_PROTO_LL ? (char*)localMem->llBuff : args->protocol == NCCL_PROTO_LL128 ? (char*)localMem->ll128Buff : localMem->buff;
void* mhandle = args->protocol == NCCL_PROTO_LL ? resources->llMhandle : args->protocol == NCCL_PROTO_LL128 ? resources->ll128Mhandle : resources->mhandle;
volatile uint64_t* sendHead = &resources->hostSendMem->head;
if ((args->tail < args->head + NCCL_STEPS) && (args->tail < *sendHead + NCCL_STEPS) && (args->tail < args->end)) {
int buffSlot = args->tail%NCCL_STEPS;
int sliceSize = stepSize * args->sliceSteps;
NCCLCHECK(ncclNetIrecv(resources->netRecvComm, localBuff+buffSlot*stepSize, sliceSize, mhandle, args->requests+buffSlot));
if (args->requests[buffSlot] != NULL) {
args->tail += args->sliceSteps;
args->idle = 0;
}
}
if (args->tail > args->head) {
int buffSlot = args->head%NCCL_STEPS;
int done, size;
NCCLCHECK(ncclNetTest(args->requests[buffSlot], &done, &size));
if (done) {
args->head += args->sliceSteps;
if (args->protocol == NCCL_PROTO_SIMPLE) {
if (resources->useGdr) NCCLCHECK(ncclNetFlush(resources->netRecvComm, localBuff+buffSlot*stepSize, size, mhandle));
resources->hostRecvMem->tail = args->head;
}
args->idle = 0;
}
}
}
if (args->head == args->end) {
resources->step = args->end;
args->idle = 0;
args->state = ncclProxyOpNone;
}
}
return ncclSuccess;
}
struct ncclTransport netTransport = {
"NET",
netCanConnect,
{ netSendSetup, netSendConnect, netSendFree, netSendProxy },
{ netRecvSetup, netRecvConnect, netRecvFree, netRecvProxy }
};