Smart Cache

About: Smart Cache is a research topic. Over the lifetime, 7680 publications have been published within this topic receiving 180618 citations.

Using prime numbers for cache indexing to eliminate conflict misses

Abstract: Using alternative cache indexing/hashing functions is a popular technique to reduce conflict misses by achieving a more uniform cache access distribution across the sets in the cache. Although various alternative hashing functions have been demonstrated to eliminate the worst case conflict behavior, no study has really analyzed the pathological behavior of such hashing functions that often result in performance slowdown. We present an in-depth analysis of the pathological behavior of cache hashing functions. Based on the analysis, we propose two new hashing functions: prime modulo and prime displacement that are resistant to pathological behavior and yet are able to eliminate the worst case conflict behavior in the L2 cache. We show that these two schemes can be implemented in fast hardware using a set of narrow add operations, with negligible fragmentation in the L2 cache. We evaluate the schemes on 23 memory intensive applications. For applications that have nonuniform cache accesses, both prime modulo and prime displacement hashing achieve an average speedup of 1.27 compared to traditional hashing, without slowing down any of the 23 benchmarks. We also evaluate using multiple prime displacement hashing functions in conjunction with a skewed associative L2 cache. The skewed associative cache achieves a better average speedup at the cost of some pathological behavior that slows down four applications by up to 7%.

Effects of Cache Coherency in Multiprocessors

Abstract: In many commercial multiprocessor systems, each processor accesses the memory through a private cache. One problem that could limit the extensibility of the system and its performance is the enforcement of cache coherence. A mechanism must exist which prevents the existence of several different copies of the same data block in different private caches. In this paper, we present an in-depth analysis of the effects of cache coherency in multiprocessors. A novel analytical model for the program behavior of a multitasked system is introduced. The model includes the behavior of each process and the interactions between processes with regard to the sharing of data blocks. An approximation is developed to derive the main effects of the cache coherency contributing to degradations in system performance.

Optimal cache allocation for Content-Centric Networking

Abstract: Content-Centric Networking (CCN) is a promising framework for evolving the current network architecture, advocating ubiquitous in-network caching to enhance content delivery. Consequently, in CCN, each router has storage space to cache frequently requested content. In this work, we focus on the cache allocation problem: namely, how to distribute the cache capacity across routers under a constrained total storage budget for the network. We formulate this problem as a content placement problem and obtain the exact optimal solution by a two-step method. Through simulations, we use this algorithm to investigate the factors that affect the optimal cache allocation in CCN, such as the network topology and the popularity of content. We find that a highly heterogeneous topology tends to put most of the capacity over a few central nodes. On the other hand, heterogeneous content popularity has the opposite effect, by spreading capacity across far more nodes. Using our findings, we make observations on how network operators could best deploy CCN caches capacity.

Proactive power-aware cache management for mobile computing systems

Abstract: Recent work has shown that invalidation report (IR)-based cache management is an attractive approach for mobile environments. However, the IR-based cache invalidation solution has some limitations, such as long query delay, low bandwidth utilization, and it is not suitable for applications where data change frequently. In this paper, we propose a proactive cache management scheme to address these issues. Instead of passively waiting, the clients intelligently prefetch the data that are most likely used in the future. Based on a novel prefetch-access ratio concept, the proposed scheme can dynamically optimize performance or power based on the available resources and the performance requirements. To deal with frequently updated data, different techniques (indexing and caching) are applied to handle different components of the data based on their update frequency. Detailed simulation experiments are carried out to evaluate the proposed methodology. Compared to previous schemes, our solution not only improves the cache hit ratio, the throughput, and the bandwidth utilization, but also reduces the query delay and the power consumption.

Cache control method and system for mixed streaming and non-streaming data

Abstract: The present invention may be embodied in a cache control method for caching disk data in a disk drive configured to receive commands for both streaming and non-streaming data from a host. A lossy state record is provided for memory segments in a cache memory. The lossy state record allows hosts commands to be mixed for streaming and non-streaming data without flushing of cache data for a command mode change.