MMT: Exploiting fine-grained parallelism in dynamic memory management

Abstract

Dynamic memory management is one of the most expensive but ubiquitous operations in many C/C++ applications. Additional features such as security checks, while desirable, further worsen memory management overheads. With advent of multicore architecture, it is important to investigate how dynamic memory management overheads for sequential applications can be reduced. In this paper, we propose a new approach for accelerating dynamic memory management on multicore architecture, by offloading dynamic management functions to a separate thread that we refer to as memory management thread (MMT). We show that an efficient MMT design can give significant performance improvement by extracting parallelism while being agnostic to the underlying memory management library algorithms and data structures. We also show how parallelism provided by MMT can be beneficial for high overhead memory management tasks, for example, security checks related to memory management. We evaluate MMT on heap allocation-intensive benchmarks running on an Intel core 2 quad platform for two widely-used memory allocators: Doug Lea's and PHKmalloc allocators. On average, MMT achieves a speedup ratio of 1.19× for both allocators, while both the application and memory management libraries are unmodified and are oblivious to the parallelization scheme. For PHKmalloc with security checks turned on, MMT reduces the security check overheads from 21% to only 1% on average.