Exchange memory optimization method based on asynchronous deduplication and recompression

The invention provides an exchange memory optimization method based on asynchronous deduplication and recompression, relates to the technical field of computers, and solves the problem that data swapped to a ZRAM space in a memory are gradually increased and the data swapped to the ZRAM space in a mobile phone device is not stable due to limited memory resources of mobile phone equipment and more applications started by a user. And compressed data continuously sent into the ZRAM space can occupy a large amount of storage space, so that the residual storage space is still small. The method comprises the following steps of: starting an independent thread in a ZRAM (Zero Random Access Memory) space for scanning, and sending a page of which the page residence time exceeds a threshold value 1 into a FLASH; for the pages exceeding the threshold value 2 but smaller than the threshold value 1, searching for repeated pages with a plurality of pagecrc, and decompressing and comparing page contents to realize page shari