Title
The Locality Descriptor: A Holistic Cross-Layer Abstraction to Express Data Locality In GPUs.
Abstract
Exploiting data locality in GPUs is critical to making more efficient use of the existing caches and the NUMA-based memory hierarchy expected in future GPUs. While modern GPU programming models are designed to explicitly express parallelism, there is no clear explicit way to express data locality---i.e., reuse-based locality to make efficient use of the caches, or NUMA locality to efficiently utilize a NUMA system. On the one hand, this lack of expressiveness makes it a very challenging task for the programmer to write code to get the best performance out of the memory hierarchy. On the other hand, hardware-only architectural techniques are often suboptimal as they miss key higher-level program semantics that are essential to effectively exploit data locality. In this work, we propose the Locality Descriptor, a cross-layer abstraction to explicitly express and exploit data locality in GPUs. The Locality Descriptor (i) provides the software a flexible and portable interface to optimize for data locality, requiring no knowledge of the underlying memory techniques and resources, and (ii) enables the architecture to leverage key program semantics and effectively coordinate a range of techniques (e.g., CTA scheduling, cache management, memory placement) to exploit locality in a programmer-transparent manner. We demonstrate that the Locality Descriptor improves performance by 26.6% on average (up to 46.6%) when exploiting reuse-based locality in the cache hierarchy, and by 53.7% (up to 2.8X) when exploiting NUMA locality in a NUMA memory system.
Year
DOI
Venue
2018
10.1109/ISCA.2018.00074
ISCA
Keywords
Field
DocType
Data Locality,GPU,Cross Layer Abstraction,Programming Interface
Locality,Memory hierarchy,Computer science,Instruction set,Parallel computing,Register file,Compiler,Exploit,General-purpose computing on graphics processing units,Microarchitecture
Conference
ISSN
ISBN
Citations 
1063-6897
978-1-5386-5984-7
7
PageRank 
References 
Authors
0.39
63
5
Name
Order
Citations
PageRank
Nandita Vijaykumar11467.55
Eiman Ebrahimi247917.23
Kevin Hsieh322310.93
Phillip B. Gibbons46863624.14
Onur Mutlu59446357.40