After an upgrade from 16.04 to 18.04, the amount of memory in use, even after a reboot, is massive. The System has 64GB of ram. Prior to upgrade, typical usage was about 20% (12GB). Ater the reboot, it's up at the 80% range.
$ cat /proc/meminfo | grep Mem MemTotal: 65898276 kB MemFree: 12725584 kB MemAvailable: 18079892 kB
Nothing in 'top' shows a high memory usage. Biggest one is about 1.3Gb resident, with a few in the GB range. Nothing that would add up to 45.7 GB currently in use.
$ps -A --sort -rss -o comm,pmem | head -n 8 COMMAND %MEM TestServr 2.0 java 1.5 java 1.0 lwsmd 0.6 gnome-shell 0.5 systemd-journal 0.4 gnome-shell 0.2
Also, Gnome-process-monitor is semi-useless as it seems to be suffering from a bug where it won't show all processes, even if you click on "All Processes".. Even if you run it as root.
What options exist for plundering the /proc filesystem to find out what process all that extra memory is allocated to?
Note, this is with almost nothing running on the system.
$ free -h total used free shared buff/cache available Mem: 62G 43G 9.0G 69M 9.9G 18G Swap: 7.6G 0B 7.6G
And this is after a fresh boot with almost no services running (not even logged in to the GUI yet, ~250 processes running, mainly system stuff like GDM, system daemons, etc.).
$ cat /tmp/free.txt total used free shared buff/cache available Mem: 62G 40G 21G 3.6M 754M 21G Swap: 7.6G 0B 7.6G
$ cat /proc/meminfo MemTotal: 65898276 kB MemFree: 9482940 kB MemAvailable: 19036072 kB Buffers: 390356 kB Cached: 8936484 kB SwapCached: 0 kB Active: 8718412 kB Inactive: 4002576 kB Active(anon): 3405360 kB Inactive(anon): 59612 kB Active(file): 5313052 kB Inactive(file): 3942964 kB Unevictable: 1856 kB Mlocked: 1856 kB SwapTotal: 7999484 kB SwapFree: 7999484 kB Dirty: 528 kB Writeback: 0 kB AnonPages: 3395996 kB Mapped: 755484 kB Shmem: 70832 kB Slab: 1141644 kB SReclaimable: 1022476 kB SUnreclaim: 119168 kB KernelStack: 18736 kB PageTables: 85152 kB NFS_Unstable: 0 kB Bounce: 0 kB WritebackTmp: 0 kB CommitLimit: 19977100 kB Committed_AS: 13634420 kB VmallocTotal: 34359738367 kB VmallocUsed: 0 kB VmallocChunk: 0 kB HardwareCorrupted: 0 kB AnonHugePages: 0 kB ShmemHugePages: 0 kB ShmemPmdMapped: 0 kB CmaTotal: 0 kB CmaFree: 0 kB HugePages_Total: 20480 HugePages_Free: 19430 HugePages_Rsvd: 320 HugePages_Surp: 0 Hugepagesize: 2048 kB DirectMap4k: 721640 kB DirectMap2M: 22274048 kB DirectMap1G: 45088768 kB