Memory management

About: Memory management is a research topic. Over the lifetime, 16743 publications have been published within this topic receiving 312028 citations. The topic is also known as: memory allocation.

Buffer memory management in a system having multiple execution entities

Abstract: A system includes multiple program execution entities (e.g., tasks, processes, threads, and the like) and a cache memory having multiple sections. An identifier is assigned to each execution entity. An instruction of one of the execution entities is retrieved and an associated identifier is decoded. Information associated with the instruction is stored in one of the cache sections based on the identifier.

WSCLOCK—a simple and effective algorithm for virtual memory management

Abstract: A new virtual memory management algorithm WSCLOCK has been synthesized from the local working set (WS) algorithm, the global CLOCK algorithm, and a new load control mechanism for auxiliary memory access. The new algorithm combines the most useful feature of WS—a natural and effective load control that prevents thrashing—with the simplicity and efficiency of CLOCK. Studies are presented to show that the performance of WS and WSCLOCK are equivalent, even if the savings in overhead are ignored.

Reducing write activities on non-volatile memories in embedded CMPs via data migration and recomputation

Abstract: Recent advances in circuit and process technologies have pushed non-volatile memory technologies into a new era. These technologies exhibit appealing properties such as low power consumption, non-volatility, shock-resistivity, and high density. However, there are challenges to which we need answers in the road of applying non-volatile memories as main memory in computer systems. First, non-volatile memories have limited number of write/erase cycles compared with DRAM memory. Second, write activities on non-volatile memory are more expensive than DRAM memory in terms of energy consumption and access latency. Both challenges will benefit from reduction of the write activities on the nonvolatile memory. In this paper, we target embedded Chip Multiprocessors (CMPs) with Scratch Pad Memory (SPM) and non-volatile main memory. We introduce data migration and recompu-tation techniques to reduce the number of write activities on non-volatile memories. Experimental results show that the proposed methods can reduce the number of writes by 59.41% on average, which means that the non-volatile memory can last 2.8 times as long as before. Meanwhile, the finish time of programs is reduced by 31.81% on average.

Determining memory conditions in a virtual machine

Abstract: Memory assigned to a virtual machine is reclaimed. A resource reservation application running as a guest application on the virtual machine reserves a location in guest virtual memory. The corresponding physical memory can be reclaimed and allocated to another virtual machine. The resource reservation application allows detection of guest virtual memory page-out by the guest operating system. Measuring guest virtual memory page-out is useful for determining memory conditions inside the guest operating system. Given determined memory conditions, memory allocation and reclaiming can be used control memory conditions. Memory conditions in the virtual machine can be controlled with the objective of achieving some target memory conditions.

Method and system for managing a display image in compressed and uncompressed blocks

Abstract: A virtual frame buffer controller in a computer's display system manages accesses to a display image stored in discrete compressed and uncompressed blocks distributed in physical memory. The controller maps conventional linear pixel addresses of a virtual frame buffer to pixel locations within blocks stored at arbitrary places in physical memory. The virtual frame buffer controller maintains a data structure, called a pointer list, to keep track of the physical memory location and compression state of each block of pixels in the virtual frame buffer. The virtual frame buffer controller initiates a decompression process to decompress a block when a pixel request maps to a pixel in a compressed block. The block remains decompressed until physical memory needs to be reclaimed to free up memory. A software driver for the virtual frame buffer controller performs memory management functions, including adding to a free memory list when the virtual frame buffer requires more memory and reclaiming memory previously allocated to a block of pixels whose state has changed from a compressed to an uncompressed state, or from a decompressed back to a compressed state.