e96c8473a150c60c68fc5c2705b0b19d15610920
5 Коммитов
| Автор | SHA1 | Сообщение | Дата | |
|---|---|---|---|---|
 Kamil Iskra
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0524aef7a0 |
NCCL 2.26.3-1
Minimize the performance impact of the device kernel profiling support when the profiler plugin is not loaded. Reduce the overheads of CUDA graph capturing, which increased in NCCL 2.26.2 for large graphs. Fix the exchange of enhanced connection establishment (ECE) options to address potential slowdowns on networks utilizing RoCE. Test if cuMem host allocations work and if not, disable them. Enabled by default since NCCL 2.24 if the CUDA driver version is at least 12.6, such allocations rely on NUMA support, which is by default not available under Docker. We recommend invoking Docker with "--cap-add SYS_NICE" to enable it. Fix an initialization error when running with NCCL_NET_GDR_C2C=1 on multiple MNNVL domains with non-uniform network configurations across nodes. Fix the printing of sub-seconds in the debug log when using a custom NCCL_DEBUG_TIMESTAMP_FORMAT setting. |
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Kamil Iskra
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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. |
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 Sylvain Jeaugey
|
6aae379278 |
2.24.3-1
Network user buffer support for collectives * Leverage user buffer registration to achieve zero-copy inter-node communications for Ring, NVLS and Collnet Add RAS subsystem * Create a RAS thread keeping track of all NCCL communicators. * Add a ncclras tool contacting the RAS thread and getting a report. Add fp8 support * Add support for e5m2 and e4m3 8-bit floating point operations. * Use Tree/PAT algorithms when possible for better numerical stability. Add NIC fusion * Add a NET API to ask the network plugin to fuse a set of interfaces together. * Fuse multiple NICs under the same PCI switch as a single, larger NIC. Socket connection failure retry * Retry in case of socket connection failure (unreachable host) * Avoid "Software caused connection abort" errors on retries QP connection failure retry * Retry in case of IB QP connection failure during ibv_modify_qp. NET API improvements * Allow plugins to force a flush in case data and completion ordering is not guaranteed. * Indicate when completion is not needed (e.g. for the LL128 protocol), allowing plugins to skip generating a completion. * Allow for full offload of allgather operations when using one GPU per node. NCCL_ALGO/NCCL_PROTO strict enforcement * Extend NCCL_ALGO/NCCL_PROTO syntax to be able to specify ALGO/PROTO filters for each collective operation. * Strictly enforce the ALGO/PROTO filters, no longer fall back on the ring algorithm when the filtering leaves no option and error out instead. Enable CUMEM host allocations * Use cumem functions for host memory allocation by default. Improved profiler plugin API * Avoid dependencies with NCCL includes. * Add information on whether the buffer is registered or not Adjust PAT tuning * Improve transition between PAT and ring at scale. Fix hangs when running with different CPU architectures * Detect when we use a mix of GPU architectures * Ensure Algo/Proto decisions are made based on that unified state. Fix FD leak in UDS * Fix a leak when mapping buffers intra-node with cumem IPCs. Fix crash when mixing buffer registration and graph buffer registration. * Separate local and graph registration to avoid crashes when we free buffers. Fix user buffer registration with dmabuf * Make ncclSend/ncclRecv communication with buffer registration functional on network plugins relying on dmabuf for buffer registration. Fix crash in IB code caused by uninitialized fields. Fix non-blocking ncclSend/ncclRecv * Fix case where ncclSend/ncclRecv would return ncclSuccess in non-blocking mode even though the operation was not enqueued onto the stream. * Issue #1495 Various compiler tweaks and fixes * PR #758 Fix typo in ncclTopoPrintGraph * Issue #1468 |
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Sylvain Jeaugey
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68b542363f |
2.23.4-1
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. |
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Sylvain Jeaugey
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3c223c105a |
2.12.7-1
Add network communication through another GPU connected with NVLink (PXN). Add aggregation of messages coming from different local GPUs through PXN and going to the same destination. Add new v5 plugin API with grouped receives and tags. Add compat for v4 plugins. Add naming of NCCL threads to help debugging. Fix NVLink detection and avoid data corruption when some NVLinks are down. Add support for Relaxed Ordering for IB. Add profiling and timing infrastructure. |