Memory utilization

Inputting 'm' can show memory utilization:

Memory utilization metrics are parsed from /proc/meminfo file (For the meaning of every metric, please refer /proc document):

$ cat /proc/meminfo
MemTotal:       196664796 kB
MemFree:        160337264 kB
MemAvailable:   177147604 kB
Buffers:         1098864 kB
Cached:         16097336 kB
SwapCached:            0 kB
Active:         19958356 kB
Inactive:       13062956 kB
......

Please beware that in proc_mem() function, some metrics are only valid if LARGEMEM macro is defined (Refer this document to know what is "Huge pages".):

void proc_mem()
{
    ......
#ifdef LARGEMEM
    ......
    p->mem.hugetotal = proc_mem_search("HugePages_Total");
    p->mem.hugefree = proc_mem_search("HugePages_Free");
    p->mem.hugesize = proc_mem_search("Hugepagesize");
#else
    p->mem.bigfree = proc_mem_search("BigFree");
#endif /*LARGEMEM*/
}

You can also press 'V' to get "virtual memory" statistics:

The information is read from /proc/vmstat:

$ cat /proc/vmstat
nr_free_pages 34583276
nr_zone_inactive_anon 77718
nr_zone_active_anon 8755682
nr_zone_inactive_file 2972621
nr_zone_active_file 1707733
nr_zone_unevictable 56
nr_zone_write_pending 19037
nr_mlock 56
......

and processed by read_vmstat() function.