A Bit-Parallel Search Algorithm for Allocating Free Space

File systems that allocate data contiguously often use bitmaps to representand managefree space. Increases in the size of storage to be managed creates a needfor eficient algorithmsfor searching these bitmaps. Wepresent an algorithm that exploits bit-parallelism, examining all bits within a processor word at the same time, to improve search performance. Measurements of our implementation show that these techniques lead to a 14 times increase in the rate at which bitmappages can be searched on a 64-bitprocessor: Trace-driven experiments indicate that overall allocation performance increases by afactor of 3 to 6 on a 32-bit processox As processors mature, registers become widel;and the degree of bit-levelparallelism increases, which makes thepeqormance improvements of our search algorithm more substantial.

• Type: Conference
• Year: 2001
• Where: MASCOTS
• Authors: Randal C. Burns, Wayne Hineman
• Keywords: Allocation Performance Increases, Bit-levelparallelism Increases, MASCOTS 2001, MASCOTS 2007, Processox As Processors