Cache invalidation

About: Cache invalidation is a research topic. Over the lifetime, 10539 publications have been published within this topic receiving 245409 citations.

Adaptive GPU cache bypassing

Abstract: Modern graphics processing units (GPUs) include hardware- controlled caches to reduce bandwidth requirements and energy consumption. However, current GPU cache hierarchies are inefficient for general purpose GPU (GPGPU) comput- ing. GPGPU workloads tend to include data structures that would not fit in any reasonably sized caches, leading to very low cache hit rates. This problem is exacerbated by the design of current GPUs, which share small caches be- tween many threads. Caching these streaming data struc- tures needlessly burns power while evicting data that may otherwise fit into the cache. We propose a GPU cache management technique to im- prove the efficiency of small GPU caches while further re- ducing their power consumption. It adaptively bypasses the GPU cache for blocks that are unlikely to be referenced again before being evicted. This technique saves energy by avoid- ing needless insertions and evictions while avoiding cache pollution, resulting in better performance. We show that, with a 16KB L1 data cache, dynamic bypassing achieves sim- ilar performance to a double-sized L1 cache while reducing energy consumption by 25% and power by 18%. The technique is especially interesting for programs that do not use programmer-managed scratchpad memories. We give a case study to demonstrate the inefficiency of current GPU caches compared to programmer-managed scratchpad memories and show the extent to which cache bypassing can make up for the potential performance loss where the effort to program scratchpad memories is impractical.

Method and apparatus for a global cache directory in a storage cluster

Abstract: A method, apparatus, article of manufacture, and a memory structure for an internode network. Nodes are active-active using commodity hardware so that the system can perform I/O together between any number of nodes, and data can be located on any given node. A single modified image is configured to maintain recent and updated data. At least one failure can occur (and be corrected) in the nodes before data is written to disk. A history of access points is kept in a cache directory, and it is assumed that the nodes most frequently accessed in the past are likely to be the most frequently accessed in the near future. One or more embodiments of the invention move this data to where it will likely be needed. This means that data is delivered to hosts quickly, as is required in high volume enterprise web environments. The symbolic list in the cache directory provides a history of the nodes that have previously performed I/O operations. When data is requested, embodiments of the invention look at the symbolic list to determine which node's cache contains the requested data. Once a new write I/O operation is performed, the symbolic list is updated to provide for the new I/O operation. Additionally, embodiments of the invention provide Fast write support, fault tolerance support, and concurrent node installation support.

Dynamic community-based cache for mobile search

Abstract: A “Community-Based Mobile Search Cache” provides various techniques for maximizing the number of query results served from a local “query cache”, thereby significantly limiting the need to connect to the Internet or cloud using 3G or other wireless links to service search queries. The query cache is constructed remotely and downloaded to mobile devices. Contents of the query cache are determined by mining popular queries from mobile search logs, either globally or based on queries of one or more groups or subgroups of users. In various embodiments, searching and browsing behaviors of individual users are evaluated to customize the query cache for particular users or user groups. The content of web pages related to popular queries may also be included in the query cache. This allows cached web pages to be displayed without first displaying cached search results when a corresponding search result has a sufficiently high click-through probability.

Adaptive line placement with the set balancing cache

Abstract: Efficient memory hierarchy design is critical due to the increasing gap between the speed of the processors and the memory. One of the sources of inefficiency in current caches is the non-uniform distribution of the memory accesses on the cache sets. Its consequence is that while some cache sets may have working sets that are far from fitting in them, other sets may be underutilized because their working set has fewer lines than the set. In this paper we present a technique that aims to balance the pressure on the cache sets by detecting when it may be beneficial to associate sets, displacing lines from stressed sets to underutilized ones. This new technique, called Set Balancing Cache or SBC, achieved an average reduction of 13% in the miss rate of ten benchmarks from the SPEC CPU2006 suite, resulting in an average IPC improvement of 5%.

MobiCache: When k-anonymity meets cache

Abstract: Location-Based Services (LBSs) are becoming increasingly popular in our daily life. In some scenarios, multiple users may seek data of same interest from a LBS server simultaneously or one by one, and they may need to provide their exact locations to the un-trusted LBS server in order to enjoy such a location-based service. Unfortunately, this will breach users' location privacy and security. To address this problem, we propose a novel collaborative system, MobiCache, which combines k-anonymity with caching together to protect user's location privacy while improving the cache hit ratio. Different from the traditional k-anonymity, our Dummy Selection Algorithm (DSA) chooses dummy locations which have not been queried before to increase the cache hit ratio. We also propose an enhanced-DSA to further improve the user's privacy as well as the cache hit ratio by assigning dummy locations which can make more contributions to cache hit ratio. Evaluation results show that the proposed DSA can increase the cache hit ratio and the enhanced-DSA can further improve the cache hit ratio as well as the user's privacy.