Files
rocm-systems/src/include/proxy.h
T
Kamil Iskra f44ac759fe NCCL 2.26.2-1
Profiler improvements
 * Add events for CUDA kernel start and end.
 * Allow network plugins to generate profiling events
 * Enable profiling on a per-operation basis, rather than per-communicator.
 * Add support for graph capturing.

Add implicit launch order
 * Allow to prevent deadlocks when using multiple NCCL communicators per
   device by implicitly ordering NCCL operations using the host program
   order. Disabled by default, set NCCL_LAUNCH_ORDER_IMPLICIT=1 to enable.
 * Add a complementary mechanism to detect host threads racing to launch
   to the same device. Enabled by default, set NCCL_LAUNCH_RACE_FATAL=0 to
   disable.

Optimize the PAT algorithm
 * Separate the computation and execution of PAT steps on different warps,
   allowing to run up to 16 PAT steps in parallel to significantly
   accelerate PAT and reduce its linear part.

Add support for setting QoS per communicator
 * Add a new trafficClass field to the communicator configuration, to
   allow the application to select a particular traffic class for a
   given communicator. The meaning of the traffic class is
   network-specific and should be set in accordance with the network
   configuration.
 * For the IB/RoCE plugin, existing config variables such as NCCL_IB_SL
   and NCCL_IB_TC take precedence.

Allow to enable GPU Direct RDMA specifically on C2C platforms
 * Disabled by default, set NCCL_NET_GDR_C2C=1 to enable.

Do not disable user buffer registration unless PXN is really used
 * Only disable UB when a communicator has more than one rank per
   node on any node.

RAS subsystem improvements
 * Report operation counts separately for each collective operation type.
 * Provide details about missing communicator ranks and reliably
   distinguish ranks that are no longer a given communicator's members
   (now reported as NOCOMM) from those that failed to respond.

Add support for timestamps to NCCL diagnostic messages
 * On by default for WARN messages; NCCL_DEBUG_TIMESTAMP_LEVELS can be
   used to enable them for other debug levels as well.
 * The format can be changed using the NCCL_DEBUG_TIMESTAMP_FORMAT config
   variable.

Reduce the memory usage with NVLink SHARP (NVLS)
 * Potentially save hundreds of MBs of device memory, considering the
   multicast buffer size granularity separately from the address alignment.

Update performance tuning for recent Intel CPUs
 * Improve algorithm/protocol selection on recent CPUs such as Emerald
   Rapids and Sapphire Rapids.

Improve channel scheduling when mixing LL and Simple operations.
 * Make LL operations account for 4x more traffic to ensure LL and simple
   operations complete at the same time.

Refactor the plugin code
 * Clean up and harmonize the support code across the network, tuner,
   and profiler plugins.

Add support for comment lines (starting with #) in the nccl.conf file
* Issue #1540.

Make user buffer registration problems print an INFO instead of a WARN.

Drop support for network plugin interface version 5.

Fix a race condition with split-shared communicators
 * NCCL could hang during connection setup if multiple communicators
   were grouped together that share resources.

Fix a performance regression when using NCCL_CROSS_NIC=1
 * NCCL would unnecessarily alternate rings, breaking the GPU-NIC
   associations.

Make GID index detection code more resilient
 * Dynamic GID detection code was giving up too soon if the
   detected index was not available (e.g., wasn't mapped to the
   container's sysfs).
 * Issues #1538, #1573.

Fix a race condition with non-blocking operation
 * Fix issue when creating a non-blocking communicator after a non-
   blocking collective operation on another communicator.

Fix shared memory usage on recent Blackwell GPUs.
 * Issues NVIDIA/nccl-tests#287, NVIDIA/nccl-tests#291, #1637.

Fix an error with NIC fusion and IB SHARP when recreating communicators
 * Disable the unloading of network plugins

Make the auto-merge failures in the NIC fusion non-fatal
 * This could happen when trying to merge IB and RoCE devices.

Fixes to ncclCommAbort
 * Fix hangs due to the progress thread spinning indefinitely on the
   network progress.
 * Reduce the abort time by up to two orders of magnitude.

Fix a crash when libnccl.so was dynamically unloaded
 * The RAS subsystem was missing a clean-up handler.

Fix a hang if the network plugin's test() call returns an error.

Fix a hang on heterogeneous architectures
 * Ensure we harmonize the tuning to avoid different tuning choices,
   causing a hang.

Fix double-free on failed ncclCommInitRank and ncclCommFinalize.

Fix a potential list traversal bug during a group launch of multiple
communicators
 * Issue #1599.

Unify the handling of NCCL configuration variables
 * Under rare circumstances, some variables specified in the config file
   could be ignored.
2025-03-12 13:46:21 -07:00

405 lines
11 KiB
C

/*************************************************************************
* Copyright (c) 2016-2022, NVIDIA CORPORATION. All rights reserved.
*
* See LICENSE.txt for license information
************************************************************************/
#ifndef NCCL_PROXY_H_
#define NCCL_PROXY_H_
#include "device.h"
#include "info.h"
#include "socket.h"
#include "ipcsocket.h"
#include "nccl_net.h"
#include <pthread.h>
#include "shmutils.h"
#include "p2p.h"
#include "collectives.h"
typedef enum : uint8_t {
ncclPatternRing,
ncclPatternRingTwice,
ncclPatternPipelineFrom,
ncclPatternPipelineTo,
ncclPatternTreeUp,
ncclPatternTreeDown,
ncclPatternTreeUpDown,
ncclPatternCollnetChain,
ncclPatternCollnetDirect,
ncclPatternNvls,
ncclPatternNvlsTree,
ncclPatternPatUp,
ncclPatternPatDown,
ncclPatternSend,
ncclPatternRecv,
ncclPatternProfiler,
} ncclPattern_t;
enum ncclProxyOpState { ncclProxyOpNone, ncclProxyOpReady, ncclProxyOpProgress };
struct ncclProxyArgs;
typedef ncclResult_t (*proxyProgressFunc_t)(struct ncclProxyState*, struct ncclProxyArgs*);
#define NCCL_PROXY_MAX_SUBS MAXCHANNELS
static_assert(2*NCCL_MAX_DEV_WORK_P2P_PER_BATCH <= MAXCHANNELS, "Not enough sub space for max work elements");
union ncclProxyOpSpecifics {
struct {
size_t sizePerRank;
int nNodes, node;
} collnetDirect;
};
struct ncclProxyOp {
struct ncclProxyConnection* connection;
ssize_t nbytes;
uint64_t opCount;
int root;
int next;
int nsteps;
size_t chunkSize;
size_t sliceSize;
size_t loopSize;
size_t loopOffset;
size_t channelSize;
uint8_t sliceSteps;
uint8_t chunkSteps;
uint8_t channelId;
uint8_t /*ncclDataType_t*/ dtype;
uint8_t /*ncclDevRedOp_t*/ redOp;
uint8_t /*ncclFunc_t*/ coll;
uint8_t /*ncclPattern_t*/ pattern;
uint8_t protocol;
uint8_t algorithm;
uint8_t reg;
// collnet/p2p/coll buffer reg handles
void* sendMhandle;
void* recvMhandle;
uint8_t* sendbuff;
uint8_t* recvbuff;
int isOneRPN;
RingAlgorithm *ringAlgo;
union ncclProxyOpSpecifics specifics;
// Profiler plugin
union {
struct ncclTaskColl* coll;
struct ncclTaskP2p* p2p;
} task;
int eActivationMask;
void* taskEventHandle;
int rank;
int peer;
pid_t pid;
void* profilerContext;
uint64_t workCounter;
struct ncclProxyOp *enqNext;
};
struct ncclProxySubArgs {
struct ncclProxyConnection* connection;
int reg;
// collnet handles
void* sendMhandle;
void* recvMhandle;
uint8_t* sendbuff;
uint8_t* recvbuff;
size_t offset;
ssize_t loopSize;
ssize_t loopOffset;
int channelId;
int nsteps;
ssize_t nbytes;
ssize_t chunkSize;
int peer;
int isOneRPN;
RingAlgorithm *ringAlgo;
int groupSize; // Number of consecutive sub operations sharing the same recvComm
uint64_t base;
uint64_t posted;
uint64_t received;
uint64_t flushed;
uint64_t transmitted;
uint64_t done;
uint64_t end;
int regBufferReady;
void* requests[NCCL_STEPS];
// Profiler plugin
int eActivationMask;
int rank;
uint64_t profilerSteps;
pid_t pid;
void* profilerContext;
void* taskEventHandle;
void* opEventHandle;
void* kernelEventHandle;
void* stepEventHandles[NCCL_STEPS];
size_t transSize;
uint64_t workCounter;
void* recvRequestsCache[NCCL_STEPS];
int recvRequestsSubCount;
};
struct ncclProxyArgs {
struct ncclProxySubArgs subs[NCCL_PROXY_MAX_SUBS];
proxyProgressFunc_t progress;
int nsubs;
int done;
int onePPN;
uint64_t opCount;
int sliceSteps;
int chunkSteps;
size_t chunkSize;
size_t totalSendSize;
size_t totalRecvSize;
size_t sendSizePerRound;
size_t recvSizePerRound;
uint8_t /*ncclDataType_t*/ dtype;
uint8_t /*ncclDevRedOp_t*/ redOp;
uint8_t /*ncclPattern_t*/ pattern;
uint8_t /*ncclFunc_t*/ coll;
uint8_t protocol;
uint8_t algorithm;
int state;
char* sharedBuff[NCCL_STEPS];
int sharedSize[NCCL_STEPS];
int idle;
// Element linking
struct ncclProxyArgs* next;
struct ncclProxyArgs* nextPeer;
struct ncclProxyArgs** proxyAppendPtr;
union ncclProxyOpSpecifics specifics;
};
#define NCCL_MAX_NETDEVS 128
// ProxyOps are used to communicate between main thread and service thread
// Make sure we have enough to store two full rounds of operations on all channels.
// Otherwise we'd be unable to post half of them to free new elements. Each
// p2p work contains a send and recv proxy op hence the 2x before it.
#define MAX_OPS_PER_PEER (2*MAXCHANNELS*2*NCCL_MAX_DEV_WORK_P2P_PER_BATCH)
struct ncclProxyOpsPool {
struct ncclProxyOp ops[MAX_OPS_PER_PEER*NCCL_MAX_LOCAL_RANKS];
volatile int nextOps;
volatile int nextOpsEnd;
volatile int freeOps[NCCL_MAX_LOCAL_RANKS];
pthread_mutex_t mutex;
pthread_cond_t cond;
};
struct ncclProxyOps {
ncclProxyOpsPool* pool;
ncclShmHandle_t handle;
int count;
int freeOp;
int nextOps;
int nextOpsEnd;
};
struct ncclProxySharedP2p {
int refcount;
int size;
char* cudaBuff;
char* hostBuff;
// CUDA IPC
ncclIpcDesc ipcDesc;
struct ncclProxyArgs* proxyAppend[MAXCHANNELS]; // Separate send and recv
};
struct ncclProxyPeer {
struct ncclProxySharedP2p send;
struct ncclProxySharedP2p recv;
};
struct ncclSharedNetComms {
void* sendComm[MAXCHANNELS];
void* recvComm[MAXCHANNELS];
int sendRefCount[MAXCHANNELS];
int recvRefCount[MAXCHANNELS];
};
struct ncclProxyPool;
struct ncclProxyProgressState {
// Used by main threads to send work to progress thread
struct ncclProxyOpsPool* opsPool;
ncclShmHandle_t handle;
char opsPoolShmSuffix[6];
pthread_t thread;
volatile int stop;
struct ncclProxyPeer** localPeers;
struct ncclSharedNetComms* netComms[NCCL_MAX_NETDEVS];
struct ncclProxyArgs* active;
struct ncclProxyArgs* pool;
struct ncclProxyPool* pools;
int nextOps;
};
// Expected proxy response fifo
struct ncclExpectedProxyResponse {
void* opId;
int respSize;
bool done;
void* respBuff;
ncclResult_t res;
struct ncclExpectedProxyResponse* next;
};
struct ncclProxyAsyncOp {
int type;
struct ncclProxyConnection* connection;
int reqSize, respSize;
char *reqBuff, *respBuff;
void* opId;
ncclProxyAsyncOp* next;
};
struct ncclProxyLocalPeer {
struct ncclSocket sock;
int tpRank;
int tpLocalRank;
ncclProxyAsyncOp* asyncOps;
int asyncOpCounter;
};
// Common response header for all proxyOps
// We pack this into a struct to reduce the number of blocking send and recv calls
struct ncclProxyRpcResponseHeader {
void* opId;
ncclResult_t res;
int respSize;
};
// UDS support
struct ncclIpcHdr {
int type;
int rank;
int reqSize;
int respSize;
void *opId;
uint64_t data[16]; // 128-bytes
};
struct ncclProxyState {
int refCount;
int tpRank;
int tpnRanks;
int tpLocalnRanks;
int cudaDev;
int p2pnChannels;
int p2pChunkSize;
int nChannels;
int buffSizes[NCCL_NUM_PROTOCOLS];
bool allocP2pNetLLBuffers;
bool dmaBufSupport;
ncclNet_t* ncclNet;
ncclCollNet_t* ncclCollNet;
uint32_t* abortFlag;
bool directMode;
// Service threads
pthread_t thread;
pthread_t threadUDS;
struct ncclSocket* listenSock;
struct ncclIpcSocket ipcSock;
int stop;
CUcontext cudaCtx;
ncclResult_t asyncResult;
// Used by main thread
union ncclSocketAddress* peerAddresses;
struct ncclSocket* peerSocks;
struct ncclProxyOps* proxyOps;
void** sharedDevMems;
struct ncclIpcSocket peerIpcSock; // cuMEM API support (UDS)
uint64_t *peerAddressesUDS; // cuMem API support (UDS)
// Progress thread
struct ncclProxyProgressState progressState;
// Profiler plugin
void* profilerContext;
// Queue of expected responses from the proxy
struct ncclExpectedProxyResponse* expectedResponses;
};
enum proxyConnectState {
connUninitialized = 0,
connInitialized = 1,
connSharedInitialized = 2,
connSetupDone = 3,
connConnected = 4,
numConnStates = 5
};
struct ncclProxyConnection {
int send, transport, shared;
int tpLocalRank, sameProcess;
struct ncclSocket* sock;
struct ncclTransportComm* tcomm;
struct ncclProxyArgs *proxyAppend;
struct ncclProxyArgs **proxyAppendPtr;
void* transportResources;
ncclNetDeviceHandle_t* netDeviceHandle;
void* mhandles[NCCL_NUM_PROTOCOLS];
proxyConnectState state;
struct ncclCollNetSharedRes* collNet;
int needsProxyProgress;
};
typedef ncclResult_t (*threadFunc_t)(struct ncclProxyArgs*);
enum proxyMode {
proxyRing = 0,
proxyFrom = 1,
proxyTo = 2
};
ncclResult_t ncclProxySaveOp(struct ncclComm* comm, struct ncclProxyOp* proxyOp, bool *justInquire);
ncclResult_t ncclProxyStart(struct ncclComm* comm);
ncclResult_t ncclProxyInit(struct ncclComm* comm, struct ncclSocket* sock, union ncclSocketAddress* peerAddresses, uint64_t *peerAddressesUDS);
ncclResult_t ncclProxyCreate(struct ncclComm* comm);
ncclResult_t ncclProxyConnect(struct ncclComm* comm, int transport, int send, int proxyRank, struct ncclProxyConnector* proxyConn);
// NB: ncclProxyMsgTypeStr[] in proxy.cc needs to match
enum ncclProxyMsgType {
ncclProxyMsgInit = 1,
ncclProxyMsgSharedInit = 2,
ncclProxyMsgSetup = 3,
ncclProxyMsgConnect = 4,
ncclProxyMsgStart = 5,
ncclProxyMsgClose = 6,
ncclProxyMsgAbort = 7,
ncclProxyMsgStop = 8,
ncclProxyMsgGetFd = 9, // cuMem API support (UDS)
ncclProxyMsgQueryFd = 10,
ncclProxyMsgRegister = 11,
ncclProxyMsgDeregister = 12
};
// This function is called by a client of the proxy that needs to invoke any of the non-progress proxyOp types
// Call this function on the client, supplying a locally unique opId. Then, poll on the return value of
// ncclPollProxyResponse(), supplying the same opId to confirm the operation has completed
ncclResult_t ncclProxyCallAsync(struct ncclComm* comm, struct ncclProxyConnector* proxyConn, int type, void* reqBuff, int reqSize, int respSize, void* opId);
// This function will internally call ncclProxyCallAsync() and spin until ncclPollProxyResponse() confirms the result is received
ncclResult_t ncclProxyCallBlocking(struct ncclComm* comm, struct ncclProxyConnector* proxyConn, int type, void* reqBuff, int reqSize, void* respBuff, int respSize);
ncclResult_t ncclPollProxyResponse(struct ncclComm* comm, struct ncclProxyConnector* proxyConn, void* respBuff, void* opId);
// UDS support
ncclResult_t ncclProxyClientGetFdBlocking(struct ncclComm* comm, int rank, void *handle, int* convertedFd);
ncclResult_t ncclProxyClientQueryFdBlocking(struct ncclComm* comm, struct ncclProxyConnector* proxyConn, int localFd, int* rmtFd);
ncclResult_t ncclProxyStop(struct ncclComm* comm);
ncclResult_t ncclProxyShmUnlink(struct ncclComm* comm);
ncclResult_t ncclProxyDestroy(struct ncclComm* comm);
#endif