I am seeing high Active usage when I do a cat /proc/meminfo :
MemTotal: 65965328 kB MemFree: 51640992 kB Buffers: 1050332 kB Cached: 8516112 kB SwapCached: 0 kB Active: 11512732 kB Inactive: 1878028 kB HighTotal: 0 kB HighFree: 0 kB LowTotal: 65965328 kB LowFree: 51640992 kB SwapTotal: 2096472 kB SwapFree: 2096472 kB Dirty: 51340 kB Writeback: 0 kB AnonPages: 3823896 kB Mapped: 132288 kB Slab: 876208 kB PageTables: 15060 kB NFS_Unstable: 0 kB Bounce: 0 kB CommitLimit: 35079136 kB Committed_AS: 4945780 kB VmallocTotal: 34359738367 kB VmallocUsed: 264384 kB VmallocChunk: 34359473967 kB HugePages_Total: 0 HugePages_Free: 0 HugePages_Rsvd: 0 Hugepagesize: 2048 kB
You can see Total Memory is 65 GB while Active usage is around 11 GB. The main java process than is running on the server isn't consuming a lot of memory ( ~ 5 % from output of top ) . I would like to know how I can dig deeper and investigate what is causing this high Active usage. I understand that this value indicates the memory actively used for buffer and page cache that cannot be reclaimed.
I am running RHEL5 kernel version 2.6.18. How can I break the "Active" usage into finer parts and identify what exactly is contributing to this high usage ?