Hi, According to this page about 1.36% of the system memory is reserved to mem_map (I confirmed it before in the code – I saw that the kernel indeed saves a struct of 65 bytes for each page, meaning 63 structs per page). I have a server (CentOS6) with 256GB of RAM, so it means that the kernel reserves about 4GB for mem_map. Most of the pages in my server are hugepages, using the kernel command line argument “hugepages=X”. I believe this means that the kernel can reserve a much smaller amount of memory for the mappings – since there are much less pages (i.e. if all pages are huges it can reserve 8MB instead of 4GB). Am I right? Any suggestions if and how it can be done? Thanks, Amitai |