Results 1 - 10 of 31

Dynamic storage allocation: A survey and critical review

by Paul R. Wilson, Mark S. Johnstone, Michael Neely, David Boles , 1995
"... Dynamic memory allocation has been a fundamental part of most computer systems since roughly 1960, and memory allocation is widely considered to be either a solved problem or an insoluble one. In this survey, we describe a variety of memory allocator designs and point out issues relevant to their de ..."
Abstract - Cited by 241 (6 self) - Add to MetaCart
Dynamic memory allocation has been a fundamental part of most computer systems since roughly 1960, and memory allocation is widely considered to be either a solved problem or an insoluble one. In this survey, we describe a variety of memory allocator designs and point out issues relevant to their design and evaluation. We then chronologically survey most of the literature on allocators between 1961 and 1995. (Scores of papers are discussed, in varying detail, and over 150 references are given.) We argue that allocator designs have been unduly restricted by an emphasis on mechanism, rather than policy, while the latter is more important; higher-level strategic issues are still more important, but have not been given much attention. Most theoretical analyses and empirical allocator evaluations to date have relied on very strong assumptions of randomness and independence, but real program behavior exhibits important regularities that must be exploited if allocators are to perform well in practice.
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A study of the allocation behavior of the SPECjvm98 Java benchmarks

by Sylvia Dieckmann, Urs Hölzle - In Proceedings of ECOOP 1999, LNCS 1628 , 1999
"... Abstract. We present an analysis of the memory usage for six of the Java programs in the SPECjvm98 benchmark suite. Most of the programs are realworld applications with high demands on the memory system. For each program, we measured as much low level data as possible, including age and size distrib ..."
Abstract - Cited by 92 (0 self) - Add to MetaCart
Abstract. We present an analysis of the memory usage for six of the Java programs in the SPECjvm98 benchmark suite. Most of the programs are realworld applications with high demands on the memory system. For each program, we measured as much low level data as possible, including age and size distribution, type distribution, and the overhead of object alignment. Among other things, we found that non-pointer data usually represents more than 50 % of the allocated space for instance objects, that Java objects tend to live longer than objects in Smalltalk or ML, and that they are fairly small. 1

The Memory Fragmentation Problem: Solved

by Mark S. Johnstone, Paul R. Wilson - Proceedings of the First International Symposium on Memory Management, ACM , 1998
"... We show that for 8 real and varied C and C++ programs, several conventional dynamic storage allocators provide nearzero fragmentation, once we account for overheads due to implementation details such as headers, alignment, etc. This substantially strengthens our previous results showing that the mem ..."
Abstract - Cited by 88 (1 self) - Add to MetaCart
We show that for 8 real and varied C and C++ programs, several conventional dynamic storage allocators provide nearzero fragmentation, once we account for overheads due to implementation details such as headers, alignment, etc. This substantially strengthens our previous results showing that the memory fragmentation problem has generally been misunderstood, and that good allocator policies can provide good memory usage for most programs. The new results indicate that for most programs, excellent allocator policies are readily available, and efficiency of implementation is the major challenge. While we believe that our experimental results are state-of-the-art and our methodology is superior to most previous work, more work should be done to identify and study unusual problematic program behaviors not represented in our sample. 1
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Using Lifetime Predictors to Improve Memory Allocation Performance

by David A. Barrett, Benjamin G. Zorn , 1993
"... Dynamic storage allocation is used heavily in many application areas including interpreters, simulators, optimizers, and translators. We describe research that can improve all aspects of the performance of dynamic storage allocation by predicting the lifetimes of short-lived objects when they are al ..."
Abstract - Cited by 77 (6 self) - Add to MetaCart
Dynamic storage allocation is used heavily in many application areas including interpreters, simulators, optimizers, and translators. We describe research that can improve all aspects of the performance of dynamic storage allocation by predicting the lifetimes of short-lived objects when they are allocated. Using five significant, allocation-intensive C programs, we show that a great fraction of all bytes allocated are short-lived (? 90% in all cases). Furthermore, we describe an algorithm for lifetime prediction that accurately predicts the lifetimes of 42--99% of all objects allocated. We describe and simulate a storage allocator that takes advantage of lifetime prediction of short-lived objects and show that it can significantly improve a program's memory overhead and reference locality, and even, at times, improve CPU performance as well.

Improving the Cache Locality of Memory Allocation

by Dirk Grunwald, Benjamin Zorn, Robert Henderson , 1993
"... The allocation and disposal of memory is a ubiquitous operation in most programs. Rarely do programmers concern themselves with details of memory allocators; most assume that memory allocators provided by the system perform well. This paper presents a performance evaluation of the reference locality ..."
Abstract - Cited by 77 (8 self) - Add to MetaCart
The allocation and disposal of memory is a ubiquitous operation in most programs. Rarely do programmers concern themselves with details of memory allocators; most assume that memory allocators provided by the system perform well. This paper presents a performance evaluation of the reference locality of dynamic storage allocation algorithms based on trace-driven simulation of five large allocation-intensive C programs. In this paper, we show how the design of a memory allocator can significantly affect the reference locality for various applications. Our measurements show that poor locality in sequential-fit allocation algorithms reduces program performance, both by increasing paging and cache miss rates. While increased paging can be debilitating on any architecture, cache misses rates are also important for modern computer architectures. We show that algorithms attempting to be space-efficient by coalescing adjacent free objects show poor reference locality, possibly negating the benef...
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Vmalloc: A General and Efficient Memory Allocator

by Kiem-Phong Vo , 1996
"... Introduction Dynamic memory allocation is an integral part of programming. Programs in C and C++ (via constructors and destructors) routinely allocate memory using the familiar ANSI-C standard interface malloc established around 1979 by Doug McIlroy. Malloc manipulates heap memory using the functi ..."
Abstract - Cited by 52 (7 self) - Add to MetaCart
Introduction Dynamic memory allocation is an integral part of programming. Programs in C and C++ (via constructors and destructors) routinely allocate memory using the familiar ANSI-C standard interface malloc established around 1979 by Doug McIlroy. Malloc manipulates heap memory using the functions malloc(s) to allocate a block of size s, free(b) to free a previously allocated block b, and realloc(b,s) to resize a block b to size s. No optimal solution to dynamic memory allocation exists [1, 2, 3] so, over the years, many malloc implementations were proposed with different tradeoffs in time and space efficiency. A study by David Korn and Phong Vo in 1985 presented and compared 11 malloc versions. Only a few of these survived the test of time. The first widely used malloc was written by McIlroy and became part of many Bell Labs Research and System V versions of the UNIX system. This malloc is based on a first-fit strategy and can be significantly slow in large memories. C. King

CustoMalloc: Efficient Synthesized Memory Allocators

by Dirk Grunwald, Benjamin Zorn - SOFTWARE—PRACTICE AND EXPERIENCE , 1993
"... ... In this paper, we describe a program (CustoMalloc) that synthesizes a memory allocator customized for a specific application. Our experiments show that the synthesized allocators are uniformly faster and more space efficient than the Berkeley UNIX allocator. Constructing a custom allocator requi ..."
Abstract - Cited by 49 (7 self) - Add to MetaCart
... In this paper, we describe a program (CustoMalloc) that synthesizes a memory allocator customized for a specific application. Our experiments show that the synthesized allocators are uniformly faster and more space efficient than the Berkeley UNIX allocator. Constructing a custom allocator requires little programmer effort, usually taking only a few minutes. Experience has shown that the synthesized allocators are not overly sensitive to properties of input sets and the resulting allocators are superior even to domain-specific allocators designed by programmers. Measurements show that synthesized allocators are from two to ten times faster than widelyused allocators

Non-Compacting Memory Allocation and Real-Time Garbage Collection

by Mark S. Johnstone , 1996
"... Garbage collection is the automatic reclamation of computer storage [Knu73, Coh81, Wil92, Wil95]. While in many systems, programmers must explicitly reclaim heap memory at some point in their program by using a "free" or "dispose" statement, garbage collected systems free the p ..."
Abstract - Cited by 30 (2 self) - Add to MetaCart
Garbage collection is the automatic reclamation of computer storage [Knu73, Coh81, Wil92, Wil95]. While in many systems, programmers must explicitly reclaim heap memory at some point in their program by using a "free" or "dispose" statement, garbage collected systems free the programmer from this burden. In spite of its obvious attractiveness for many applications, garbage collection for real-time programs is not popular. This is largely due to the perceived cost and disruptiveness of garbage collection in general, and of incremental garbage collection in particular. Most existing "real-time" garbage collectors are not in fact usefully real-time, largely due to the use of a read barrier to trigger incremental copying of data structures being traversed by the running application. This may slow down running applications unpredictably, even though individual increments of garbage collection work are small and bounded. We have developed a hard real-time garbage collector which us...

Partition Selection Policies in Object Database Garbage Collection

by Jonathan Cook, Alexander L. Wolf, Benjamin G. Zorn - IN PROC. INT. CONF. ON MANAGEMENT OF DATA (SIGMOD) , 1994
"... The automatic reclamation of storage for unreferenced objects is very important in object databases. Existing language system algorithms for automatic storage reclamation have been shown to be inappropriate. In this paper, we investigate methods to improve the performance of algorithms for automatic ..."
Abstract - Cited by 29 (5 self) - Add to MetaCart
The automatic reclamation of storage for unreferenced objects is very important in object databases. Existing language system algorithms for automatic storage reclamation have been shown to be inappropriate. In this paper, we investigate methods to improve the performance of algorithms for automatic storage reclamation of object databases. These algorithms are based on a technique called partitioned garbage collection, in which a subset of the entire database is collected independently of the rest. Specifically, we investigate the policy that is used to select what partition in the database should be collected. The policies that we propose and investigate are based on the intuition that the values of overwritten pointers provide good hints about where to find garbage. Using trace-driven simulation, we show that one of our policies requires less I/O to collect more garbage than any existing implementable policy and performs close to a near-optimal policy over a wide range of database s...
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Evaluating Models of Memory Allocation

by Benjamin Zorn, Dirk Grunwald - ACM TRANSACTIONS ON MODELING AND COMPUTER SIMULATION , 1992
"... Because dynamic memory management is an important part of a large class of computer programs, high-performance algorithms for dynamic memory management have been, and will continue to be, of considerable interest. We evaluate and compare models of the memory allocation behavior in actual programs an ..."
Abstract - Cited by 28 (6 self) - Add to MetaCart
Because dynamic memory management is an important part of a large class of computer programs, high-performance algorithms for dynamic memory management have been, and will continue to be, of considerable interest. We evaluate and compare models of the memory allocation behavior in actual programs and investigate how these models can be used to explore the performance of memory management algorithms. These models, if accurate enough, provide an attractive alternative to algorithm evaluation based on trace-driven simulation using actual traces. We explore a range of models of increasing complexity including models that have been used by other researchers. Based on our analysis, we draw three important conclusions. First, a very simple model, which generates a uniform distribution around the mean of observed values, is often quite accurate. Second, two new models we propose show greater accuracy than those previously described in the literature. Finally, none of the models investigated ap...