Sylvain Jeaugey
60240fec77
Add scalable init API
* Add new ncclCommInitRankScalable to allow for passing multiple
unique IDs to the init function.
* Spreads the load onto multiple bootstrap roots, allowing for
constant bootstrap time.
* Requires multiple ranks to create a unique ID, and the CPU-side
ID exchange code to call allgather[v] instead of broadcast.
Accelerate init bootstrap operations
* Reduce the number of calls to allgather.
* Allow roots to reply early to ranks when information is already
available.
* Add an option to use ncclNet instead of sockets to perform
bootstrap allgather operations.
Add PAT algorithms for Allgather and ReduceScatter
* Parallel Aggregated Trees, variation of Bruck algorithm.
* Logarithmic number of network steps for small sizes at scale.
* Only supports one rank per node at the moment.
Add support for registered buffers for intra-node communication.
* Allow registered user buffers to be accessed directly intra-node
* Avoids extra copies in algorithms which permit it, saving
memory bandwidth and helping with compute overlap.
Add profiler plugin API
* New plugin API for profiling
* Supports various levels of profiling, with a hierarchy.
Asynchronous graph allocation
* Make calls to cudaMalloc and cudaMemcpy during graph allocation
asynchronous.
* Significantly speeds up graph capture.
Use fatal IB asynchronous events to stop network operation
* Avoids many other error messages
* Only fatal errors are affected; potentially transient errors
(e.g. port down) do not cause an immediate stop.
Set P2P level to PXB on AMD CPUs when using more than 2 GPUs per node
* P2P would cause a significant performance degradation when using
many GPUs, and therefore many interleaved data flows.
* Disable P2P through the CPU when we have 3+ GPUs per node; keep it
enabled when we only have 2 GPUs.
Improve the init logs to report the real NCCL function.
* Make the log report ncclCommInitRank or ncclCommSplit, rather than
the generic ncclCommInitRankFunc.
Add a parameter to set the location of the user configuration file.
* Add NCCL_CONF_FILE environment variable to set where the user's
configuration file resides.
Increase default IB timeout
* Increase IB timeout value from 18 to 20.
* Should help avoid fatal errors on large RoCE systems.
Add new check for nvidia peermem
* On linux kernels 6.6+, /sys/kernel/mm/memory_peers is no longer
present; check for /sys/module/nvidia_peermem/version instead.
Fix old performance regression when mixing small and large operations.
* Improves distribution of work on channels.
Fix crash when NUMA IDs are equal to -1.
* Can happen when a NIC is a virtual NIC, or when linux doesn't
know which NUMA node a device is attached to
* Issue NVIDIA/nccl-tests#233
Fix tree graph search when NCCL_CROSS_NIC is set to 1.
* Would force NCCL to use the balanced_tree pattern, thereby
disabling LL128 on platforms with 1 GPU+1 NIC per PCI switch.
* Would also try to use alternate rings even though it was not
needed.
Compiler tweaks and fixes
* PR #1177
* PR #1228
Fix stack smash
* PR #1325
Fixes for multi-node NVLink + IB operation
Coverity fixes and comments.
[ROCm/rccl commit: 68b542363f]
61 라인
1.6 KiB
C
61 라인
1.6 KiB
C
/*************************************************************************
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* Copyright (c) 2022, NVIDIA CORPORATION. All rights reserved.
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*
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* See LICENSE.txt for license information
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************************************************************************/
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#ifndef NCCL_TIMER_H_
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#define NCCL_TIMER_H_
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#if ENABLE_TIMER
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#include <unistd.h>
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#include <sys/time.h>
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#include <x86intrin.h>
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static double freq = -1;
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static void calibrate() {
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struct timeval tv;
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gettimeofday(&tv, NULL);
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uint64_t timeCycles = __rdtsc();
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double time = - tv.tv_sec*1E6 - tv.tv_usec;
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uint64_t total = 0ULL;
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for (int i=0; i<10000; i++) total += __rdtsc();
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gettimeofday(&tv, NULL);
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timeCycles = __rdtsc() - timeCycles;
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time += tv.tv_sec*1E6 + tv.tv_usec;
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freq = timeCycles/time;
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}
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static inline double gettime() {
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if (freq == -1) calibrate();
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return __rdtsc()/freq;
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}
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static uint64_t counts[8];
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static double times[8];
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static double startTimes[8];
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#define TIME_START(index) do { \
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counts[index]++; \
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startTimes[index] = gettime(); \
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} while (0)
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#define TIME_STOP(index) do { \
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times[index] += gettime() - startTimes[index]; \
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} while (0)
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#define TIME_CANCEL(index) do { \
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counts[index]--; \
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} while (0)
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#define TIME_PRINT(name) do { \
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printf("%s stats", name); \
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for (int i=0; i<8; i++) { \
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if (counts[i]) printf(" [%d] %g/%ld = %g", i, times[i], counts[i], times[i]/counts[i]); \
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counts[i] = 0; \
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} \
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printf("\n"); \
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} while (0)
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#else
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#define TIME_START(index) do {} while(0)
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#define TIME_STOP(index) do {} while(0)
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#define TIME_CANCEL(index) do {} while(0)
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#define TIME_PRINT(name)
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#endif
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#endif
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