T3: Transparent Tracking & Triggering for Fine-grained Overlap of Compute & Collectives

Fuente: arXiv
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Auteurs principaux: Pati, Suchita, Aga, Shaizeen, Islam, Mahzabeen, Jayasena, Nuwan, Sinclair, Matthew D.
Format: Preprint
Publié: 2024
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author Pati, Suchita
Aga, Shaizeen
Islam, Mahzabeen
Jayasena, Nuwan
Sinclair, Matthew D.
author_facet Pati, Suchita
Aga, Shaizeen
Islam, Mahzabeen
Jayasena, Nuwan
Sinclair, Matthew D.
contents Large Language Models increasingly rely on distributed techniques for their training and inference. These techniques require communication across devices which can reduce scaling efficiency as the number of devices increases. While some distributed techniques can overlap, and thus, hide this communication with independent computations, techniques such as Tensor Parallelism (TP) inherently serialize communication with model execution. One approach to hide this serialized communication is to interleave it with the producer operation (of the communicated data) in a fine-grained manner. However, this fine-grained interleaving of communication and computation in software can be difficult. Furthermore, as with any concurrent execution, it requires compute and memory resources to be shared between computation and communication, causing resource contention that reduces overlapping efficacy. To overcome these challenges, we propose T3 which applies hardware-software co-design to transparently overlap serialized communication while minimizing resource contention with compute. T3 transparently fuses producer operations with the subsequent communication via a simple configuration of the producer's output address space and requires minor software changes. At the hardware level, T3 adds a lightweight track and trigger mechanism to orchestrate the producer's compute, and communication. It further uses compute-enhanced memories for communication's attendant compute. As a result, T3 reduces resource contention, and efficiently overlaps serialized communication with computation. For important Transformer models like T-NLG, T3 speeds up communication-heavy sublayers by 30% geomean (max 47%) and reduces data movement by 22% geomean (max 36%). Furthermore, T3's benefits persist as models scale: geomean 29% for sublayers in $\sim$500-billion parameter models, PALM and MT-NLG.
format Preprint
id arxiv_https___arxiv_org_abs_2401_16677
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle T3: Transparent Tracking & Triggering for Fine-grained Overlap of Compute & Collectives
Pati, Suchita
Aga, Shaizeen
Islam, Mahzabeen
Jayasena, Nuwan
Sinclair, Matthew D.
Hardware Architecture
Distributed, Parallel, and Cluster Computing
Machine Learning
C.2.4; C.1.2
Large Language Models increasingly rely on distributed techniques for their training and inference. These techniques require communication across devices which can reduce scaling efficiency as the number of devices increases. While some distributed techniques can overlap, and thus, hide this communication with independent computations, techniques such as Tensor Parallelism (TP) inherently serialize communication with model execution. One approach to hide this serialized communication is to interleave it with the producer operation (of the communicated data) in a fine-grained manner. However, this fine-grained interleaving of communication and computation in software can be difficult. Furthermore, as with any concurrent execution, it requires compute and memory resources to be shared between computation and communication, causing resource contention that reduces overlapping efficacy. To overcome these challenges, we propose T3 which applies hardware-software co-design to transparently overlap serialized communication while minimizing resource contention with compute. T3 transparently fuses producer operations with the subsequent communication via a simple configuration of the producer's output address space and requires minor software changes. At the hardware level, T3 adds a lightweight track and trigger mechanism to orchestrate the producer's compute, and communication. It further uses compute-enhanced memories for communication's attendant compute. As a result, T3 reduces resource contention, and efficiently overlaps serialized communication with computation. For important Transformer models like T-NLG, T3 speeds up communication-heavy sublayers by 30% geomean (max 47%) and reduces data movement by 22% geomean (max 36%). Furthermore, T3's benefits persist as models scale: geomean 29% for sublayers in $\sim$500-billion parameter models, PALM and MT-NLG.
title T3: Transparent Tracking & Triggering for Fine-grained Overlap of Compute & Collectives
topic Hardware Architecture
Distributed, Parallel, and Cluster Computing
Machine Learning
C.2.4; C.1.2
url https://arxiv.org/abs/2401.16677