Decongest: Accelerating Super-Dense PCM under Write Disturbance by Hot Page Remapping

Rujia Wang Sparsh Mittal Youtao Zhang Jun Yang
Abstract: At small feature sizes, phase change memory (PCM) shows write disturbance (WD) error (WDE) and this issue can eclipse the density and energy efficiency advantage of PCM. We propose 'Decongest', a technique to address WD errors in main memory designed with super-dense (4F2 cell size) PCM. Decongest works by identifying and remapping write- intensive hot pages to a WD-free spare area, which avoids WD to nearby pages due to writing these hot pages, and WD to these hot pages from writing nearby pages. Compared ...