Optimize In-kernel swap memory by avoiding duplicate swap out pages
Srividya Desireddy, Dinakar Reddy Pathireddy · 2016
On embedded devices the physical memory is a critical resource. RAM should be used very efficiently without affecting the performance of the device. In-kernel memory swapping is a Linux feature which creates RAM based swap area and provides a form of virtual memory compression. It increases performance by using a compressed block device in RAM for paging instead of disk. Since In-kernel memory swapping is an alternative way to provide swapping, the memory utilized to store the compressed swapped pages should be optimized. Through experiments it is observed that duplicate pages are swapped by kernel to the swap area, which leads to redundant pages being stored and hence increasing the swap area. This paper proposes a new mechanism to avoid duplicate compressed pages swapped to the In-RAM swap area. Experiments have assured increase in the available physical memory and there by improved the performance of applications even at low memory conditions.