… much memory are you wasting with double buffering by not using of O_DIRECT. Besides general clues such as 50% of… fast and it does not disturbs OS file cache by using mincore function to get pages which are currently in cache. This… logfile unless in recovery these are waste and Innodb could use fadvice to give instruction to kernel not to cache these…

Perl used in this tool just for wrapping C-code, in which mincore called. P.S. Sorry for broken english