Memory footprint
Encyclopedia
Memory footprint refers to the amount of main memory that a program uses or references while running.
This includes all sorts of active memory regions like code, static data sections (both initialized and uninitialized), heap, as well as all the stacks, plus memory required to hold any additional data structures, such as symbol tables, constant tables, debugging structures, open files, etc, that the program ever needs while executing and will be loaded at least once during the entire run.
Larger programs have larger memory footprints. Excessive number of utility classes and methods in a programming language design would increase the footprint for API users even if they did not use non-standard plug-ins or applications. Programs themselves often do not contribute the largest portions to their own memory footprints; rather, structures introduced by the run-time environment take up most of the memory. For example, a C++ compiler inserts vtables, type_info objects and many temporary and anonymous objects that are active during a program's execution. In a Java program the memory footprint is predominantly made up of the runtime environment in form of the Java Virtual Machine
(JVM) itself that is loaded indirectly when a Java application launches.
During the 1990s, computer memory became cheaper and programs with larger memory footprints became commonplace. This trend has been mostly due to the widespread use of computer software, from large enterprise-wide applications that consume vast amounts of memory (such as databases), to memory intensive multimedia authoring and editing software. To tackle the ever increasing memory needs, Virtual Memory
systems were introduced that divide the available memory into equally-sized portions and loads them from "pages" stored on the hard-disk on an as-and-when required basis.
This approach to support programs with huge-memory-footprints has been quite successful. Most modern operating systems including Microsoft Windows
, Apple's Mac OS X
, and all versions of Linux
and Unix
provide Virtual memory systems.
With the proliferation of intelligent consumer electronics or embedded systems, low-memory-footprint programs have regained importance once more. Low-memory-footprint programs are of paramount to running applications on embedded platforms where memory is often constrained to within a few MBs – so much so that developers typically sacrifice efficiency (processing speeds) just to make program footprints small enough to fit into the available RAM. So much so that Sun Microsystems
has now brought out a version of its Java Virtual Machine
(JVM) for these devices; it goes by the name of KVM
. The KVM works on platforms where memory is in Kilobytes as opposed to the Megabytes (or even Gigabytes) of memory available on even a regular home PC.
This includes all sorts of active memory regions like code, static data sections (both initialized and uninitialized), heap, as well as all the stacks, plus memory required to hold any additional data structures, such as symbol tables, constant tables, debugging structures, open files, etc, that the program ever needs while executing and will be loaded at least once during the entire run.
Larger programs have larger memory footprints. Excessive number of utility classes and methods in a programming language design would increase the footprint for API users even if they did not use non-standard plug-ins or applications. Programs themselves often do not contribute the largest portions to their own memory footprints; rather, structures introduced by the run-time environment take up most of the memory. For example, a C++ compiler inserts vtables, type_info objects and many temporary and anonymous objects that are active during a program's execution. In a Java program the memory footprint is predominantly made up of the runtime environment in form of the Java Virtual Machine
Java Virtual Machine
A Java virtual machine is a virtual machine capable of executing Java bytecode. It is the code execution component of the Java software platform. Sun Microsystems stated that there are over 4.5 billion JVM-enabled devices.-Overview:...
(JVM) itself that is loaded indirectly when a Java application launches.
During the 1990s, computer memory became cheaper and programs with larger memory footprints became commonplace. This trend has been mostly due to the widespread use of computer software, from large enterprise-wide applications that consume vast amounts of memory (such as databases), to memory intensive multimedia authoring and editing software. To tackle the ever increasing memory needs, Virtual Memory
Virtual memory
In computing, virtual memory is a memory management technique developed for multitasking kernels. This technique virtualizes a computer architecture's various forms of computer data storage , allowing a program to be designed as though there is only one kind of memory, "virtual" memory, which...
systems were introduced that divide the available memory into equally-sized portions and loads them from "pages" stored on the hard-disk on an as-and-when required basis.
This approach to support programs with huge-memory-footprints has been quite successful. Most modern operating systems including Microsoft Windows
Microsoft Windows
Microsoft Windows is a series of operating systems produced by Microsoft.Microsoft introduced an operating environment named Windows on November 20, 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces . Microsoft Windows came to dominate the world's personal...
, Apple's Mac OS X
Mac OS X
Mac OS X is a series of Unix-based operating systems and graphical user interfaces developed, marketed, and sold by Apple Inc. Since 2002, has been included with all new Macintosh computer systems...
, and all versions of Linux
Linux
Linux is a Unix-like computer operating system assembled under the model of free and open source software development and distribution. The defining component of any Linux system is the Linux kernel, an operating system kernel first released October 5, 1991 by Linus Torvalds...
and Unix
Unix
Unix is a multitasking, multi-user computer operating system originally developed in 1969 by a group of AT&T employees at Bell Labs, including Ken Thompson, Dennis Ritchie, Brian Kernighan, Douglas McIlroy, and Joe Ossanna...
provide Virtual memory systems.
With the proliferation of intelligent consumer electronics or embedded systems, low-memory-footprint programs have regained importance once more. Low-memory-footprint programs are of paramount to running applications on embedded platforms where memory is often constrained to within a few MBs – so much so that developers typically sacrifice efficiency (processing speeds) just to make program footprints small enough to fit into the available RAM. So much so that Sun Microsystems
Sun Microsystems
Sun Microsystems, Inc. was a company that sold :computers, computer components, :computer software, and :information technology services. Sun was founded on February 24, 1982...
has now brought out a version of its Java Virtual Machine
Java Virtual Machine
A Java virtual machine is a virtual machine capable of executing Java bytecode. It is the code execution component of the Java software platform. Sun Microsystems stated that there are over 4.5 billion JVM-enabled devices.-Overview:...
(JVM) for these devices; it goes by the name of KVM
K virtual machine
The K virtual machine is a virtual machine developed by Sun Microsystems , derived from the Java Virtual Machine specification. The KVM was written from scratch in C. It is designed for small devices and has a small memory footprint. It supports a subset of the features of the higher end JVM...
. The KVM works on platforms where memory is in Kilobytes as opposed to the Megabytes (or even Gigabytes) of memory available on even a regular home PC.